Re: CALCULATORS

[Shmuel Metz]

In <Pine.LNX.4.64.12...@darkstar.example.net>, on
08/19/2012
at 09:35 PM, Michael Black <et...@ncf.ca> said:

>I think you could get cheap ones, probably for learning to use
>one in high school,

In my HS a good slide rule was a status symbol. I don't know of any
classmate that had an el cheapo slipstick.

--
Shmuel (Seymour J.) Metz, SysProg and JOAT <http://patriot.net/~shmuel>

Unsolicited bulk E-mail subject to legal action. I reserve the
right to publicly post or ridicule any abusive E-mail. Reply to
domain Patriot dot net user shmuel+news to contact me. Do not
reply to spam...@library.lspace.org

[Shmuel Metz]

In <Pine.LNX.4.64.12...@darkstar.example.net>, on
08/19/2012

at 10:46 PM, Michael Black <et...@ncf.ca> said:

>I remember about 1998, I saw a forsale poster somewhere. And he
>offered I think it wsa a PDP8 for a hundred dollars. It was almost
>something I was willing to spend, and it was certainly that vintage
>of microcomputer.

I believe that the PDP-8 used discrete transistors.

[Shmuel Metz]

In <k0s4tn$kig$2...@dont-email.me>, on 08/19/2012
at 08:46 PM, "Charles Richmond" <nume...@aquaporin4.com> said:

>"Hard disk storage" seemed adaquate for most of the rest of the
>computer industry.

I know of nobody in the computer industry that called a CRAM, drum,
RACE or TBM "Hard disk storage".

[Shmuel Metz]

In <87ipcek...@blp.benpfaff.org>, on 08/19/2012
at 10:51 AM, Ben Pfaff <b...@cs.stanford.edu> said:

>It depends. At least the AMD version of the x86 architecture has an
>instruction named SYSCALL.

That came much later, as did IBM's Program Call.

[Simon Turner]

On Friday, in article
<502e6228$8$fuzhry+tra$mr2...@news.patriot.net>
spam...@library.lspace.org.invalid "Seymour J. Shmuel Metz"
wrote:

> In <20120817.08...@twoplaces.co.uk>, on 08/17/2012
> at 09:11 AM, si...@twoplaces.co.uk (Simon Turner) said:
>
> >The Delightful Rod is far from the only person who posts to afc via
> >news.individual.net,
>
> Still, if they can't or won't control the morphing of their trolls
> their trolls, it's tempting. Think of it as an extension of the UIP.

Hmmmm. Morphing sock puppets could make an interesting subject for
complaint! Their use policy is quite simple, but does say that valid
e-mail addresses should be used in postings.

> >Much better to quietly killfile all Rod's assorted sock puppets, and
> >add new ones each time they pop up.
>
> If they pop up from the same provider, it's easier to just add an
> entry from the provider one time.

Well, it's certainly easier; but I don't like the idea of killfiling
innocent bystanders as well as the culprit, especially when I find many
of the bystanders' contributions worthwhile. YMMV.

--
Simon Turner DoD #0461
si...@twoplaces.co.uk
Trust me -- I know what I'm doing! -- Sledge Hammer

[Shmuel Metz]

In <proto-F22CAB....@news.panix.com>, on 08/20/2012
at 08:28 AM, Walter Bushell <pr...@panix.com> said:

>Ah, I remember when an employee of a company I was working for
>brought in his 9.6K baud modem for me to use.

Almost certainly 9600 bps, not 9600 baud.

[Shmuel Metz]

In <PM0004C7B...@aca228fc.ipt.aol.com>, on 08/20/2012
at 01:36 PM, jmfbahciv <See....@aol.com> said:

>IIRC, LIGHTS UUO isn't software.

UUO isn't software, but making use of it for something refereed to as
a system call is software.

[Simon Turner]

On 18 Aug, in article
<PM0004C78...@ac8409ec.ipt.aol.com> See....@aol.com
"jmfbahciv" wrote:

> Simon Turner wrote:
> > On 17 Aug, in article
> > <PM0004C77...@ac83b7da.ipt.aol.com>
> > See....@aol.com "jmfbahciv" wrote:
> >
> >> If you don't read replies to speedo's posts, then you have missed some
> >> very interesting posts.
> >
> > I'm well aware of that, and I used to just kill speedo's posts so I
> > could try to pick out the worthwhile replies; but I found it impossible
> > to read the replies without also reading (some of) what he had written,
>
> I just skip it while I'm scanning the post.

I found I couldn't. Some part of it would catch my eye and I'd find my
blood pressure rising.

> IMO, Morten's write-ups are worth the stress. He would not have done
> some of them if I hadn't talked with speedo.

That would make an interesting mod to my script: look for long posts by
non-Rods (esp. Morten) that have a high ratio of new material to quoted
stuff, and don't mark them as read. Hmmmmm.

(I find wading through 200 lines of quoted material just to find two
lines of new stuff annoying, too; I wish more people would trim before
replying! But the old customs are dying out: there's one group I skim
where the local netiquette has it that trimming posts before replying is
a Bad Thing, because it makes you look as though you're trying to hide
something. They have a lot of rather unpleasant arguments in that
group, which has obviously skewed perceptions over the years.)

> > Indeed. I'm alarmed by the amount I can't recall about software I wrote
> > only a few years ago...
>
> <grin> TW couldn't remember what he wrote yesterday. OTOH, JMF remembered
> every line of code and why it was written the way it was written.

Would that I could have JMF's memory. Even with my (in)famous reams of
comments I still sometimes find myself wondering why I did something in
a particular way; and to cap it all, recently I accepted a minor feature
request to some old software and actually got part of the way into the
job before realising that I'd already implemented the feature when I
first wrote the code six years ago, but the user hadn't spotted it. 8-/

[Walter Banks]

Peter Flass wrote:

> On 8/19/2012 11:15 PM, Joe Pfeiffer wrote:
> > Peter Flass <Peter...@Yahoo.com> writes:
> >
> >> On 8/19/2012 3:36 PM, hanc...@bbs.cpcn.com wrote:
> >>> On Aug 18, 6:48 pm, "Joe Morris" <j.c.mor...@verizon.net> wrote:
> >>>
> >>>> The meaning of "accurate" depends on several criteria, including how many
> >>>> decimal places are required.
> >>>
> >>> Correct. If memory serves, a slide rule was only good for roughly
> >>> three digit accuracy. Even simple BASIC gave six digit accuracy. Of
> >>> course, a slide rule was a lot more portable than a Teletype. <g> In
> >>> the early 1970s, it was far cheaper ($3) than an electronic calculator
> >>> ($100+). But calculators quickly came down in price and improved in
> >>> functionality making the slide rule obsolete by the late 1970s.
> >>
> >> I think a good slide rule cost a lot more than $3, even in 1970.
> >
> > I'm trying to remember what my K&E slide rule cost in 1975 -- for some
> > reason, $35 is sticking in my memory.

I remember paying about $22 or $23 Canadian for a K&E in the mid 60's
complete with leather case belt hook and significant instruction manual. (A
manual I opened for the first time during an office move) The first slide rule
I bought was in the mid 60's a Faber-Castell 57/87 I don't remember
what I paid but it was sub $10.

I was looking up side rules a few minutes ago and ran across the following
web site that publishes scales and constriction details for many different
slide rules
http://sliderulemuseum.com/SR_Scales.htm

w..

[Michael Black]

On Sun, 19 Aug 2012, Joe Pfeiffer wrote:

> Peter Flass <Peter...@Yahoo.com> writes:
>
>> On 8/19/2012 3:36 PM, hanc...@bbs.cpcn.com wrote:
>>> On Aug 18, 6:48 pm, "Joe Morris" <j.c.mor...@verizon.net> wrote:
>>>
>>>> The meaning of "accurate" depends on several criteria, including how many
>>>> decimal places are required.
>>>
>>> Correct. If memory serves, a slide rule was only good for roughly
>>> three digit accuracy. Even simple BASIC gave six digit accuracy. Of
>>> course, a slide rule was a lot more portable than a Teletype. <g> In
>>> the early 1970s, it was far cheaper ($3) than an electronic calculator
>>> ($100+). But calculators quickly came down in price and improved in
>>> functionality making the slide rule obsolete by the late 1970s.
>>
>> I think a good slide rule cost a lot more than $3, even in 1970.
>
> I'm trying to remember what my K&E slide rule cost in 1975 -- for some

> reason, $35 is sticking in my memory. It was just a few months after I
> bought it that the first great handheld calculator price collapse
> happened, and I bought a
> http://www.thimet.de/calccollection/calculators/Melcor-SC-535/Contents.htm
> just as I was going off to college. It's funny that, as I was looking
> for a link to the calculator, all the pages I'm finding are saying it
> was introduced at under $100 in 1974 -- I sure didn't hear of it until
> the next year!
>
>
I've never heard of Melcor. But I recall a gap after the HP-35. It hit
and made a big splash, though maybe I got that impression since someone I
knew had one, bought at his work place in a group deal. So unlike so many
other things (that I only saw in ads), I actually had the HP-35 in my
hands early.

If the Melcor was really $100 in 1974, surely we would have heard of it.
That was significantly less than the HP-35. I remember a National
calculator, I'm sure it arrived in 1975, and it got good coverage because
it was lower in price (though I can't remember the price). It took a
while (though I'm not sure how long was a "while", it's always longer when
you're living through it) before there was a scientific calculator within
my range.

Michael

[Michael Black]

On Mon, 20 Aug 2012, Shmuel (Seymour J.) Metz wrote:

> In <Pine.LNX.4.64.12...@darkstar.example.net>, on
> 08/19/2012
> at 09:35 PM, Michael Black <et...@ncf.ca> said:
>
>> I think you could get cheap ones, probably for learning to use
>> one in high school,
>
> In my HS a good slide rule was a status symbol. I don't know of any
> classmate that had an el cheapo slipstick.
>

It's a time that I just missed. The HP-35 arrived a couple of years
before I might have gone to slide rule, and by the time the need might
have arrived, scientific calculators were within reason.

I was given a small slide rule, and some brief instructions, from the
friend who got an HP-35 very early. Six inch slide rule, I guess I
thought that one might be cheap. I don't know where it went. I actually
have a 12" Gruning slide rule that came later in a bunch of junk, but
I never played with the small one long enough to remember how to use it.

Michael

[Michael Black]

On Mon, 20 Aug 2012, Shmuel (Seymour J.) Metz wrote:

> In <Pine.LNX.4.64.12...@darkstar.example.net>, on
> 08/19/2012
> at 10:46 PM, Michael Black <et...@ncf.ca> said:
>
>> I remember about 1998, I saw a forsale poster somewhere. And he
>> offered I think it wsa a PDP8 for a hundred dollars. It was almost
>> something I was willing to spend, and it was certainly that vintage
>> of microcomputer.
>
> I believe that the PDP-8 used discrete transistors.
>

Yes, and I slipped. That should have been "minicomputer". I do know the
difference.

Michael

[Charlie Gibbs]

In article <Pine.LNX.4.64.12...@darkstar.example.net>,
et...@ncf.ca (Michael Black) writes:

> The concept of a slide rule was of course used in other things, and
> I can't remember if it was here that I mentioned that fairly recently.
> I had something, maybe circular, from some audio company that
> converted dB into something, a relatively simple thing. You could
> get such things for figuring out how many turns of wire a given
> inductance needed, for making coils in radio. I'm sure there were
> lots of similar specialized things. Of course, maybe they classify
> more as a sliding or revolving lookup table.

My wife, who once worked in printing, still has a specialized
circular slide rule that was called a "proportional rule", and
was used for various printing-related calculations.

And, of course, any aviator (at least beyond a certain age),
is familiar with the good old E6B a circular slide rull, full
of scales for various aviation-related calculations, complete
with a vector calculator on the back.

--
/~\ cgi...@kltpzyxm.invalid (Charlie Gibbs)
\ / I'm really at ac.dekanfrus if you read it the right way.
X Top-posted messages will probably be ignored. See RFC1855.
/ \ HTML will DEFINITELY be ignored. Join the ASCII ribbon campaign!

[Peter Flass]

About the power of a 4004 though?


--
Pete

[hanc...@bbs.cpcn.com]

On Aug 19, 7:51 pm, Peter Flass <Peter_Fl...@Yahoo.com> wrote:

> I think a good slide rule cost a lot more than $3, even in 1970.

Oh yes. The $3 unit was a cheap one for school students, made by
Sterling Plastics. It had the A, B, CI, C, D, K scales, and the S, L,
T scales on the flip side. (Though it is stamped "made in USA"). No
case.

I have no idea what a good one cost.

IIRC, every student had to chemistry in their junior year, and the
class included lessons on how to use a slide rule. If someone took
physics (which I think was optional) they used it for that, too.

I don't know if liberal arts majors needed it in college, but sci/eng
students certainly did for chemistry and physics.

But as mentioned, once good pocket calculators came out, everyone
switched quickly.

[hanc...@bbs.cpcn.com]

On Aug 20, 8:24 am, Shmuel (Seymour J.) Metz

<spamt...@library.lspace.org.invalid> wrote:

> In my HS a good slide rule was a status symbol. I don't know of any
> classmate that had an el cheapo slipstick.

In my HS a good slide rule meant that it was old and a hand-me-down
from an uncle or father.

Almost all of us used the Sterling plastic unit, which, IIRC, was $3
at the school store.

[hanc...@bbs.cpcn.com]

On Aug 19, 10:46 pm, Michael Black <et...@ncf.ca> wrote:

> I remember about 1998, I saw a forsale poster somewhere.  And he offered I
> think it wsa a PDP8 for a hundred dollars.  It was almost something I was

> willing to spend, and it was certainly that vintage of microcomputer.  In
> contrast, he had a modem (I forget the speed, but it was "cutting edge" at
> the time) that he priced higher than the computer.

Many collectors of old stuff will buy something only to get a very
specific part of it. For instance, old telephone collectors will buy
an old telephone set just to get the old-style number card.

[hanc...@bbs.cpcn.com]

On Aug 19, 9:35 pm, Michael Black <et...@ncf.ca> wrote:

> The concept of a slide rule was of course used in other things, and I
> can't remember if it was here that I mentioned that fairly recently.  I
> had something, maybe circular, from some audio company that converted dB
> into something, a relatively simple thing.  You could get such things for
> figuring out how many turns of wire a given inductance needed, for making
> coils in radio.  I'm sure there were lots of similar specialized things.
> Of course, maybe they classify more as a sliding or revolving lookup
> table.

Circular slide rules were developed for a wide variety of purposes.
As mentioned, theyr'e used in aviation. Kodak made them to aid in
photographic printing and to calculate enlarger exposure times.

Some circular and linear slide rules were made of inexpensive
materials and distributed by companies as advertising novelties. For
instance, one scale would show an application and the other scale,
once matched to it, would show the recommended product for that
application.

[John Levine]

>>> I believe that the PDP-8 used discrete transistors.
>>>
>> Yes, and I slipped. That should have been "minicomputer". I do know
>> the difference.
>>
>
>About the power of a 4004 though?

No, the PDP-8 was considerably faster. It was 12 bit parallel (other
than the later 8/S) and had a 1.5us cycle time, so it could do a 12
bit add in 3us. A 4004 had a 10us instruction time.

For applications where 12 bits was enough, which included a lot of
data aquisition and control, the -8 was quite fast.

R's,
John
--
Regards,
John Levine, jo...@iecc.com, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. http://jl.ly

[Charlie Gibbs]

In article
<79691b02-49c3-4065...@v12g2000vbc.googlegroups.com>,

hanc...@bbs.cpcn.com (hancock4) writes:

> IIRC, every student had to chemistry in their junior year, and the
> class included lessons on how to use a slide rule. If someone took
> physics (which I think was optional) they used it for that, too.

Did you have the 6-foot-long demo slide rule hanging on the wall?

Come to think of it, there was a similarly-enlarged E6B at a recent
aviation seminar I attended. So I guess they're not dead yet.

[Ahem A Rivet's Shot]

On Mon, 20 Aug 2012 10:45:26 -0700 (PDT)
hanc...@bbs.cpcn.com wrote:

> On Aug 19, 7:51 pm, Peter Flass <Peter_Fl...@Yahoo.com> wrote:
>
> > I think a good slide rule cost a lot more than $3, even in 1970.
>
> Oh yes. The $3 unit was a cheap one for school students, made by
> Sterling Plastics. It had the A, B, CI, C, D, K scales, and the S, L,
> T scales on the flip side. (Though it is stamped "made in USA"). No
> case.

That sounds identical to the ones sold in the school tuck shop when
I started senior school in the UK (1970) I forget what it cost but it
wouldn't have been more than £2-3.

> IIRC, every student had to chemistry in their junior year, and the
> class included lessons on how to use a slide rule. If someone took
> physics (which I think was optional) they used it for that, too.

First year maths started with an introduction to Napier's bones (we
all made a set) and followed through into teaching us how to use the slide
rules. Once we had the basics slide rule drill competitions were the first
five minutes of every maths lesson for the next five years. Physics and
Chemistry lessons just assumed we knew how to use a slide rule.

> But as mentioned, once good pocket calculators came out, everyone
> switched quickly.

Yes, strangely even those of us who had seen calculator users lose
out to slide rule users time after time still bought calculators.

--
Steve O'Hara-Smith | Directable Mirror Arrays
C:>WIN | A better way to focus the sun
The computer obeys and wins. | licences available see
You lose and Bill collects. | http://www.sohara.org/

[rectifier]

"Shmuel (Seymour J.)Metz" <spam...@library.lspace.org.invalid> wrote in
message news:50322c8b$20$fuzhry+tra$mr2...@news.patriot.net...

> In <Pine.LNX.4.64.12...@darkstar.example.net>, on
> 08/19/2012
> at 09:35 PM, Michael Black <et...@ncf.ca> said:
>
>>I think you could get cheap ones, probably for learning to use
>>one in high school,
>
> In my HS a good slide rule was a status symbol. I don't know of any
> classmate that had an el cheapo slipstick.

That says more about your HS than anything else.

[Rod Speed]

Shmuel (Seymour J.)Metz <spam...@library.lspace.org.invalid> wrote

> Michael Black <et...@ncf.ca> wrote

>> I remember about 1998, I saw a forsale poster somewhere.
>> And he offered I think it wsa a PDP8 for a hundred dollars.
>> It was almost something I was willing to spend, and it was
>> certainly that vintage of microcomputer.

> I believe that the PDP-8 used discrete transistors.

Some did, some didn�t.

[hanc...@bbs.cpcn.com]

On Aug 20, 3:23 pm, "Charlie Gibbs" <cgi...@kltpzyxm.invalid> wrote:

> > IIRC, every student had to chemistry in their junior year, and the
> > class included lessons on how to use a slide rule.  If someone took
> > physics (which I think was optional) they used it for that, too.
>
> Did you have the 6-foot-long demo slide rule hanging on the wall?

Yes, they had one of those.

For whatever reason, they didn't spend very much time teaching us how
to use the slide rule. I think we only learned the C and D scales to
do multiplication and division.

I don't recall if it was chemistry or physics, but the classroom lab
had a large barometer and thermometer mounted on the wall. It had
very fine graduations. I completely forgot what experiments required
the barometric pressure, but I admired the thing. I think it was old.

[glen herrmannsfeldt]

In comp.lang.pl1 "Shmuel (Seymour J.) Metz" <spam...@library.lspace.org.invalid> wrote:

(snip)
>>For one, it takes up a lot less space. To read directly, it has to
>>be, or at least had to be, FB 80. (The Fortran compilers I remember
>>required FB 80.)

> VB worked fine for PL/I.

I suspected so. I remember once trying to use the usual (for Fortran)
FB 133 for SYSPRINT and geting a nice message telling me what the
DCB parameters should be, I believe VB 125. It seemed likely that
it would allow VB for SYSIN, but I never tried it.

>>I did use TSO for one summer, and I believe that I did it the same
>>way as with WYLBUR. As well as I remember, though, they were FB 80
>>so the reason above doesn't apply.

> TSO EDIT has a table of characteristics by data set type. When you
> keep your source code in the appropriate PDS, you automatically get
> the right settings, which are not always the ones for JCL.

WYLBUR users usually have a PDS name LIB, in EDIT (RECFM=U) format.
I do remember once having a CARDLIB, PDS in FB80, but I don't
remember what I used it for.

-- glen

[Michael Black]

On Mon, 20 Aug 2012, Charlie Gibbs wrote:

> In article <Pine.LNX.4.64.12...@darkstar.example.net>,
> et...@ncf.ca (Michael Black) writes:
>
>> The concept of a slide rule was of course used in other things, and
>> I can't remember if it was here that I mentioned that fairly recently.
>> I had something, maybe circular, from some audio company that
>> converted dB into something, a relatively simple thing. You could
>> get such things for figuring out how many turns of wire a given
>> inductance needed, for making coils in radio. I'm sure there were
>> lots of similar specialized things. Of course, maybe they classify
>> more as a sliding or revolving lookup table.
>
> My wife, who once worked in printing, still has a specialized
> circular slide rule that was called a "proportional rule", and
> was used for various printing-related calculations.
>
> And, of course, any aviator (at least beyond a certain age),
> is familiar with the good old E6B a circular slide rull, full
> of scales for various aviation-related calculations, complete
> with a vector calculator on the back.
>

Nobody really talks about circular slide rules. I remember seeing them
ina catalog, I suspect it was Edmund Scientific, and wanting one.
SOmehow they seemed especially neat.

Michael

[Michael Black]

I don't know. It was 12bits of data, which surely made things a lot
easier than a 4bit CPU. I thought the PDP8 had a better instruction set,
but I have no idea what I base that on. I did mention a while back that
someone I knew got a contract to make new controllers for a local record
pressing plant in 1979, and the guy he got to do the work used the
Intersil 6100, which ran the PDP8 instuction set. I assumed that was
chosen since he was used to the PDP8.

Michael

[Michael Black]

But there's always that split. Seling a collection intact is so much
easier, but selling separately likely raises the overall price. Few want
to buy a lot of "junk" (to them) to get the key items. Since I still read
the Apple II newsgroup, I see it there. By now, just about anyone who
needs or wants an Apple II has one or a few, but there are plenty of
things that were never bought much back then, which can be a desired item.
If it's embeded in all kinds of things like the Z80 card, and the floppy
drives and an 80 column card and a monitor and printer, you're just paying
for a lot of shipping, at the very least, to get the single item.

On the other hand, I've seen people complain about someone going in the
other direction, selling a board and manual separately, or in the antique
radio newsgroup, someone selling off an old radio in bits and pieces.
There, yes there are "junkers" that aren't worth repairing, so they should
be sacrificed to keep other radios going, but who determines what a junker
is? The seller may simply think he can make more money selling a good
radio in pieces.

Michael

[John Levine]

>> I believe that the PDP-8 used discrete transistors.
>

>Some did, some didn’t.

The original PDP-8 was build out of discrete transistors on small
(about 4x6") plug in flip-chip cards. Later models went to SSI and
eventually to the 6120 which was an entire PDP-8 processor on a chip.

It didn't run PL/I, though.

[Michael Black]

On Mon, 20 Aug 2012, John Levine wrote:

>>> I believe that the PDP-8 used discrete transistors.
>>
>> Some did, some didn’t.
>
> The original PDP-8 was build out of discrete transistors on small
> (about 4x6") plug in flip-chip cards. Later models went to SSI and
> eventually to the 6120 which was an entire PDP-8 processor on a chip.
>

It was a slipup on my part to call it a microcomputer. Yes, the term
applied to computers that came along using IC based CPUs, but I think
"microcomputer" is more a generic thing, applying to a certain vague type
of computer. I guess price, maybe size, maybe market aim, defines it.

Nowadays, I don't think anyone much has a "micromcomputer", they just have
computers.

Michael

[Peter Flass]

Yes, I remember those. These days they'd probably have to distribute
some sort of electronic calculator-like device to connect with their
customers. It's be cheap enough though.

--
Pete

[Peter Flass]

On 8/20/2012 4:41 PM, Michael Black wrote:
> On Mon, 20 Aug 2012, Peter Flass wrote:
>
>> On 8/20/2012 11:58 AM, Michael Black wrote:
>>> On Mon, 20 Aug 2012, Shmuel (Seymour J.) Metz wrote:
>>>
>>>> In <Pine.LNX.4.64.12...@darkstar.example.net>, on
>>>> 08/19/2012
>>>> at 10:46 PM, Michael Black <et...@ncf.ca> said:
>>>>
>>>>> I remember about 1998, I saw a forsale poster somewhere. And he
>>>>> offered I think it wsa a PDP8 for a hundred dollars. It was almost
>>>>> something I was willing to spend, and it was certainly that vintage
>>>>> of microcomputer.
>>>>
>>>> I believe that the PDP-8 used discrete transistors.
>>>>
>>> Yes, and I slipped. That should have been "minicomputer". I do know
>>> the difference.
>>>
>>
>> About the power of a 4004 though?
>>
> I don't know. It was 12bits of data, which surely made things a lot
> easier than a 4bit CPU. I thought the PDP8 had a better instruction set,

I thought it was terrible, but then I started with the 1130 and 360/ I
did like the PDP-11, except for the little-endian part.

--
Pete

[Joe Morris]

"Charlie Gibbs" <cgi...@kltpzyxm.invalid> wrote:

> And, of course, any aviator (at least beyond a certain age),
> is familiar with the good old E6B a circular slide rull, full
> of scales for various aviation-related calculations, complete
> with a vector calculator on the back.

One problem with the E6B is that too many people, hearing that identifier,
assume you're referring to the Boeing E-6 Mercury airborne C3 that was based
on one of the Boeing 707.

http://www.navy.mil/navydata/fact_display.asp?cid=1100&tid=800&ct=1

as opposed to the pilot's computer (and yes, that's the word used to refer
to the E6B):

http://en.wikipedia.org/wiki/E6B

...of which I've still got (somewhere) several that I used, either in the
cockpit or in teaching fledgling pilot trainees.

Incidentally...earlier this year the USAF bought 18,000 iPads as part of the
EFB ("Electronic Flight Bag") program to replace the large, heavy flight bag
with paper charts , E6B, and various "stuff" that accumulates in a typical
flight bag. I have no idea if the E6B is still taught to military
pilots...I hope so, since it has one possibly critical advantage over the
iPad: no batteries required.

Joe

[Joe Morris]

<hanc...@bbs.cpcn.com> wrote:

>I don't recall if it was chemistry or physics, but the classroom lab
>had a large barometer and thermometer mounted on the wall. It had
>very fine graduations. I completely forgot what experiments required
>the barometric pressure, but I admired the thing. I think it was old.

Aneroid or mercury barometer? If it was a mercury barometer then the column
would have had a scale next to it, with a vernier to allow very precise
measurement of the column height.

Many of the older mercury barometers were works of art, but their age, their
fragility, and the advent of excellent pressure transducers that need only
occasional calibration has made them much less common. The last time I was
at the National Weather Service facility (LWX) at Dulles International
Airport the mercury barometer was still in the facility, but one of the
forecasters said that it would be removed as soon as NWS could complete the
paperwork required to move hazardous material.

Joe

[Warren Adams]

On 8/19/2012 6:51 PM, Peter Flass wrote:
> On 8/19/2012 3:36 PM, hanc...@bbs.cpcn.com wrote:
>> On Aug 18, 6:48 pm, "Joe Morris" <j.c.mor...@verizon.net> wrote:
>>
>>> The meaning of "accurate" depends on several criteria, including how
>>> many
>>> decimal places are required.
>>
>> Correct. If memory serves, a slide rule was only good for roughly
>> three digit accuracy. Even simple BASIC gave six digit accuracy. Of
>> course, a slide rule was a lot more portable than a Teletype. <g> In
>> the early 1970s, it was far cheaper ($3) than an electronic calculator
>> ($100+). But calculators quickly came down in price and improved in
>> functionality making the slide rule obsolete by the late 1970s.
>

> I think a good slide rule cost a lot more than $3, even in 1970.
>

I purchased my Post slide rule in 1960. I think it was about $25.
I agree with the ~3 digit accuracy. Except that at work mid 60's, we
had a "double precision" slide rule. It was twice as long as the usual
slide rule, so you could get 4-5 digit accuracy. Only one I have ever
seen like it.

[Robin Vowels]

On Aug 21, 6:19 am, glen herrmannsfeldt <g...@ugcs.caltech.edu> wrote:

> In comp.lang.pl1 "Shmuel (Seymour J.) Metz" <spamt...@library.lspace.org.invalid> wrote:
>
> (snip)
>
> >>For one, it takes up a lot less space. To read directly, it has to
> >>be, or at least had to be, FB 80. (The Fortran compilers I remember
> >>required FB 80.)
> > VB worked fine for PL/I.
>
> I suspected so. I remember once trying to use the usual (for Fortran)
> FB 133 for SYSPRINT and geting a nice message telling me what the
> DCB parameters should be, I believe VB 125.

IIRC, it could only be FB and 133. Fortran output records were
of fixed size.

> It seemed likely that
> it would allow VB for SYSIN,

Cards and card images were 80 bytes, and so FB (80) was necessary.

[Joe Pfeiffer]

One of my little treasures is an Otis King cylindrical slide rule I
picked up on ebay a while ago -- this isn't a circular slide rule (I
have some of those too!), it's cylindrical. The scale spirals up the
cylinder. See http://www.hpmuseum.org/srcyl.htm

[hanc...@bbs.cpcn.com]

On Aug 20, 7:20 pm, "Joe Morris" <j.c.mor...@verizon.net> wrote:

> Aneroid or mercury barometer?  If it was a mercury barometer then the column
> would have had a scale next to it, with a vernier to allow very precise
> measurement of the column height.

Pretty sure it was mercury. I didn't know its age, but probably from
the 1950s at the latest, maybe earlier, judging by the type style on
the scales.

We had to take both the pressure and temperature for our lab
experiments. But the whole thing was pointless since the barometer
was located in a corner which was much colder than the rest of the
room, so it didn't really reflect our workbench. Further, we were
kids and barely knew what we were doing.

Chemistry was not my thing. Moles. Avogadros' number. Ions.
Akaline. Acids. Reagants (NY State Board of).

[hanc...@bbs.cpcn.com]

On Aug 20, 8:10 pm, Warren Adams <adam...@hiwaay.net> wrote:

> I purchased my Post slide rule in 1960.  I think it was about $25.
> I agree with the ~3 digit accuracy.  Except that at work mid 60's, we
> had a "double precision" slide rule.  It was twice as long as the usual
> slide rule, so you could get 4-5 digit accuracy.  Only one I have ever

> seen like it.-

Actually, I couldn't see any difference between my cheapo $3 slide
rule and some of the kids who had their father's industrial strength
slide rule made of special materials.

I would've thought that people in industry would have thd "double
precision" slide rule you mention; indeed, I don't know how they got
along without such a tool.

If the answer number began with a nine, it was not going to be very
accurate.

[glen herrmannsfeldt]

In comp.lang.pl1 Robin Vowels <robin....@gmail.com> wrote:

(snip)

>> > VB worked fine for PL/I.

>> I suspected so. I remember once trying to use the usual (for Fortran)
>> FB 133 for SYSPRINT and geting a nice message telling me what the
>> DCB parameters should be, I believe VB 125.

That was for PL/I (F).

> IIRC, it could only be FB and 133. Fortran output records were
> of fixed size.

>> It seemed likely that
>> it would allow VB for SYSIN,

> Cards and card images were 80 bytes, and so FB (80) was necessary.

That is what I used, but, as previously noted, PL/I (F) allows VB
and, I believe, LRECL greater than 80.

-- glen

[Joe Pfeiffer]

Precision was pretty much a function of length.

"Niceness" had a lot to do with how it felt to use -- a bamboo slide
rule was great; it had just the right "stickiness" that it wouldn't move
unless you wanted it to, and then it would move as far as you wanted. A
steel slide rule (I've got one of them, too!) would tend to move when
you didn't want it to. A plastic slide rule would take too much force
to get it to move at all, and when it did finally come unstuck, would
invariably go too far.

[Gene Wirchenko]

On Sun, 19 Aug 2012 22:46:05 -0400, Michael Black <et...@ncf.ca>
wrote:

[snip]

>The same thing with amateur radio equipment. Though, in the early
^^^^^^^^^^^^^^^^^^^^^^^
>seventies a lot of it was cheap, since nobody wanted tubes and nobody
>wanted equipment that didn't do the voice mode that everyone had moved
>onto. I remember getting lots of stuff back then, playing with it a bit,
>trading it. But i was using it, not collecting it.
>
>And it's only in recent decades that it's become valued. The decades have
>thinned out the heard, and enough time has passed that people regret
^^^^^
Fortuitous typo!

>getting rid of their stuff decades ago. So the demand is up, and stock is
>lower, hence higher costs.
>
>The time to collect is when the stuff is obsolete, but before it becomes
>desirable.

>
>I remember about 1998, I saw a forsale poster somewhere. And he offered I
>think it wsa a PDP8 for a hundred dollars. It was almost something I was

>willing to spend, and it was certainly that vintage of microcomputer. In
>contrast, he had a modem (I forget the speed, but it was "cutting edge" at
>the time) that he priced higher than the computer.

Sincerely,

Gene Wirchenko

[j...@arcade.demon.co.uk]

Ahem A Rivet's Shot wrote:
> Yes, strangely even those of us who had seen calculator users lose
> out to slide rule users time after time still bought calculators.

I used to be able to do trig to 2 dps with pen and paper, which
sufficed for 'O' levels (age 16), but strained for 'A' levels
(age 18), so I saved up to buy a calculator, which I still have
30 years later. I can still to SIN and COS to 1dp in my head,
not that I ever find myself needing to ;)

JGH

[Shmuel Metz]

In <k0u652$r12$1...@speranza.aioe.org>, on 08/20/2012

at 08:19 PM, glen herrmannsfeldt <g...@ugcs.caltech.edu> said:

>I suspected so. I remember once trying to use the usual (for
>Fortran) FB 133 for SYSPRINT and geting a nice message telling me
>what the DCB parameters should be, I believe VB 125. It seemed
>likely that it would allow VB for SYSIN, but I never tried it.

PL/I, yes, FORTRAN, no, at least not in OS/360.

>WYLBUR users usually have a PDS name LIB, in EDIT (RECFM=U) format.

The good news is that it's compressed; the bad news is that Wylbur
didn't automatically set characteristics for particular languages.

[Shmuel Metz]

In <Pine.LNX.4.64.12...@darkstar.example.net>, on
08/20/2012

at 04:38 PM, Michael Black <et...@ncf.ca> said:

>Nobody really talks about circular slide rules.

FSVO nobody. I certainly saw students using them.

[Christian Brunschen]

[ much snippage ]

Interestingly enough, this just popped up elsewhere:

http://www.tnmoc.org/news/upcoming-events/international-meeting-slide-rule-collectors

"The largest meeting of slide rule collectors ever held will be hosted by
the UK Slide Rule Circle (UKSRC) at The National Museum of Computing
(TNMOC) and Bletchley Park on 21-22 September 2012.

Delegates from nine countries will meet for the 18th International Meeting
of Slide Rule Collectors (IM 2012) and have a chance to see TNMOC and
Bletchley Park.

At TNMOC, the organisers, the UK Slide Rule Circle, sponsors a diverse
display of slide rules, those calculating instruments that were used
universally in aircraft design up until the 1970s, and were indispensable
to the American space programme, and especially tax collectors. For over
350 years slide rules were the principal calculating tool until the
introduction of the electronic calculator made them redundant virtually
overnight.

Anyone interested in attending the event should contact
colina...@talktalk.net"

Best wishes,

// Christian

[Patrick Scheible]

I had one of those. It was neat, however it was well into the
calculator era so after I learned basic use it languished in a drawer
for a long time.

-- Patrick

[glen herrmannsfeldt]

In comp.lang.pl1 Shmuel (Seymour J.) Metz <spam...@library.lspace.org.invalid> wrote:

(snip, I wrote)

>>I suspected so. I remember once trying to use the usual (for
>>Fortran) FB 133 for SYSPRINT and geting a nice message telling me
>>what the DCB parameters should be, I believe VB 125. It seemed
>>likely that it would allow VB for SYSIN, but I never tried it.

> PL/I, yes, FORTRAN, no, at least not in OS/360.

Yes, that is what I was trying to say. I was used to FB 133 from
Fortran, and put that on my DCB for PL/I (F). It didn't work.
PL/I (F) wants VB for output, so not so surprising that it would
allow VB for input. Not for sure, but not surprising.

I believe it wants LRECL=125, and not as Robin indicates 137.

-- glen

[Peter Flass]

Yes, SYSPRINT is limited to 120 character records.


--
Pete

[David W Noon]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On Tue, 21 Aug 2012 14:03:18 -0400, Peter Flass wrote about Re: 1132
printer history:

>On 8/21/2012 12:41 PM, glen herrmannsfeldt wrote:

[snip]

>> Yes, that is what I was trying to say. I was used to FB 133 from
>> Fortran, and put that on my DCB for PL/I (F). It didn't work.
>> PL/I (F) wants VB for output, so not so surprising that it would
>> allow VB for input. Not for sure, but not surprising.
>>
>> I believe it wants LRECL=125, and not as Robin indicates 137.
>
>Yes, SYSPRINT is limited to 120 character records.

We've always been able to specify the attributes in PL/I code:

DCL SYSPRINT PRINT ENV(VB RECSIZE(137));

OPEN FILE(SYSPRINT) LINESIZE(132);

This will then override anything specified in the JCL, except if the
BLKSIZE is too small for the LRECL/RECSIZE. With F-Level, the default
was LINESIZE(120), but the above code overrides that too.
- --
Regards,

Dave [RLU #314465]
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
dwn...@spamtrap.ntlworld.com (David W Noon)
Remove spam trap to reply by e-mail.
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.19 (GNU/Linux)

iEYEARECAAYFAlAz3F4ACgkQ9MqaUJQw2Ml4uACeNXWoc5VLLEXQWhXvqSRrpvSj
f4EAn1B4LLYnyhvVQqx7MEJnvEsX1seq
=/vc4
-----END PGP SIGNATURE-----

[glen herrmannsfeldt]

In comp.lang.pl1 David W Noon <dwn...@spamtrap.ntlworld.com> wrote:

(snip, I wrote)

>>> Yes, that is what I was trying to say. I was used to FB 133 from
>>> Fortran, and put that on my DCB for PL/I (F). It didn't work.
>>> PL/I (F) wants VB for output, so not so surprising that it would
>>> allow VB for input. Not for sure, but not surprising.

>>> I believe it wants LRECL=125, and not as Robin indicates 137.

>>Yes, SYSPRINT is limited to 120 character records.

Or 121 if you include carriage control.

> We've always been able to specify the attributes in PL/I code:

> DCL SYSPRINT PRINT ENV(VB RECSIZE(137));

> OPEN FILE(SYSPRINT) LINESIZE(132);

I was talking about the compiler SYSPRINT (listing).

The Fortran compilers write FB, and PL/I (F) VB.

If I remember, there is a nice message, presumably WTO, indicating
VB, 125, and, if I remember N*125+4 for BLKSIZE. Given VB, I never
knew why it had to be a nice multple (plus the BDW), though.

For run time, you can choose any LRECL you want, at least any that
the OS allows.

-- glen

[glen herrmannsfeldt]

In comp.lang.pl1 David W Noon <dwn...@spamtrap.ntlworld.com> wrote:

[snip]
(I wrote)

>>> I believe it wants LRECL=125, and not as Robin indicates 137.

WTO 'IEM3896I SYSPRINT BLOCKSIZE IS NOT OF FORM 4 +N*125',

This one doesn't say VB, somehow I found that out.

But why does the BLKSIZE have to be 4*N+125? The whole idea of VB is
that you can write different length records. Even if the compiler
only writes 121+4, it should still allow other lengths.

-- glen

[Joe Morris]

On Aug 21, 6:19 am, glen herrmannsfeldt <g...@ugcs.caltech.edu> wrote:

> "Shmuel (Seymour J.) Metz" wrote:

> > VB worked fine for PL/I.

> I suspected so. I remember once trying to use the usual (for Fortran)
> FB 133 for SYSPRINT and geting a nice message telling me what the
> DCB parameters should be, I believe VB 125.

H'mmm...I think that you must have been sending the output to a printer with
a 120-character line. 125 bytes, minus 1 for carriage control, minus 4 for
the green word leaves 120 bytes for data, and many printers had 120 print
positions.

Joe

[glen herrmannsfeldt]

In comp.lang.pl1 Joe Morris <j.c.m...@verizon.net> wrote:

>> I suspected so. I remember once trying to use the usual (for Fortran)
>> FB 133 for SYSPRINT and geting a nice message telling me what the
>> DCB parameters should be, I believe VB 125.

> H'mmm...I think that you must have been sending the output to a printer with
> a 120-character line. 125 bytes, minus 1 for carriage control, minus 4 for
> the green word leaves 120 bytes for data, and many printers had 120 print
> positions.

For spooled, and I believe also non-spooled, output, you can write
shorter records than the printer width.

I believe that there were some 120 character printers in addition
to the more popular 132 character wide printers. (Maybe even
some models of the 1403.)

-- glen

[brian]

On 22/08/12 11:57 AM, glen herrmannsfeldt wrote:

>
> I believe that there were some 120 character printers in addition
> to the more popular 132 character wide printers. (Maybe even
> some models of the 1403.)
>

I recall going to a client site to install a program that had assumed a
132-wide printer, and found a 120. Of course, this was totally
unanticipated. The program had been written for local use, and the
client was being given a copy as a favour - we weren't in the IT
services or software business. Needless to say, the printer width was
not a parameter, and there were nasty consequences for the page
formatting in changing it. It took the best part of a day to fix it,

This was Easycoder on Honeywell H200 machines in about 1966.

--brian



--

[Peter Flass]

In this case BLKSIZE can be anything >= 129 (one record). [that's 4+N
above, you wrote 4*N, typo?) 4 btes for BLKSIZE, 4 for RECSIZE, 1 for
carriage control, and up to 120 bytes of data.

--
Pete

[Shmuel Metz]

In <k115v...@news3.newsguy.com>, on 08/21/2012

at 07:35 PM, "Joe Morris" <j.c.m...@verizon.net> said:

>H'mmm...I think that you must have been sending the output to a
>printer with a 120-character line.

No, just that the specific program was written for 120.
RECFM=VBA,LRECL=125 will work fine going to a wider printer.

[glen herrmannsfeldt]

In comp.lang.pl1 Peter Flass <Peter...@yahoo.com> wrote:

(snip, I wrote)

>> WTO 'IEM3896I SYSPRINT BLOCKSIZE IS NOT OF FORM 4 +N*125',

(snip)

>> But why does the BLKSIZE have to be 4*N+125? The whole idea of VB is
>> that you can write different length records. Even if the compiler
>> only writes 121+4, it should still allow other lengths.

> In this case BLKSIZE can be anything >= 129 (one record). [that's 4+N
> above, you wrote 4*N, typo?) 4 btes for BLKSIZE, 4 for RECSIZE, 1 for
> carriage control, and up to 120 bytes of data.

Yes I exchanged the + and *. Must be typing too fast.

In FB, the BLKSIZE is supposed to be an integer multiple of LRECL.
But for VB, why should BLKSIZE be 4 plus an integer multiple
of LRECL?

-- glen

[Charles Richmond]

<hanc...@bbs.cpcn.com> wrote in message
news:79691b02-49c3-4065...@v12g2000vbc.googlegroups.com...

On Aug 19, 7:51 pm, Peter Flass <Peter_Fl...@Yahoo.com> wrote:

>> I think a good slide rule cost a lot more than $3, even in 1970.
>

>Oh yes. The $3 unit was a cheap one for school students, made by
>Sterling Plastics. It had the A, B, CI, C, D, K scales, and the S, L,
>T scales on the flip side. (Though it is stamped "made in USA"). No
>case.

Hmmm... I had a Sterling plastic slide rule back in the late 60's. I'm sure
it had a dark grey slip case, open on one end. Sort of like a sword
scabbart. I think it cost something like $2.95 or $3.95. *Not* expensive,
but well within high school affordability. I may still have this slide rule
*somewhere*.

A few of the Sterling plastic slide rules (sans case) are available on eBay
for little money.

--

numerist at aquaporin4 dot com

[Charles Richmond]

"Peter Flass" <Peter...@Yahoo.com> wrote in message
news:k0udjk$3g5$1...@dont-email.me...
> On 8/20/2012 1:49 PM, hanc...@bbs.cpcn.com wrote:
>>
>> [snip...] [snip...]
>> [snip...]
>>
>> Some circular and linear slide rules were made of inexpensive
>> materials and distributed by companies as advertising novelties. For
>> instance, one scale would show an application and the other scale,
>> once matched to it, would show the recommended product for that
>> application.
>>
>
> Yes, I remember those. These days they'd probably have to distribute some
> sort of electronic calculator-like device to connect with their customers.
> It's be cheap enough though.
>

These days, they distribute "free apps" for your iPhone, iPad, iPod Touch,
or Android phone or tablet. Usually these things are in the regular app
store.

[Charles Richmond]

"Warren Adams" <ada...@hiwaay.net> wrote in message
news:5rKdncTEfo6bT6_N...@posted.hiwaay2...

> On 8/19/2012 6:51 PM, Peter Flass wrote:
>> On 8/19/2012 3:36 PM, hanc...@bbs.cpcn.com wrote:
>>> On Aug 18, 6:48 pm, "Joe Morris" <j.c.mor...@verizon.net> wrote:
>>>
>>>> The meaning of "accurate" depends on several criteria, including how
>>>> many
>>>> decimal places are required.
>>>
>>> Correct. If memory serves, a slide rule was only good for roughly
>>> three digit accuracy. Even simple BASIC gave six digit accuracy. Of
>>> course, a slide rule was a lot more portable than a Teletype. <g> In
>>> the early 1970s, it was far cheaper ($3) than an electronic calculator
>>> ($100+). But calculators quickly came down in price and improved in
>>> functionality making the slide rule obsolete by the late 1970s.
>>

>> I think a good slide rule cost a lot more than $3, even in 1970.
>>

> I purchased my Post slide rule in 1960. I think it was about $25.
> I agree with the ~3 digit accuracy. Except that at work mid 60's, we had
> a "double precision" slide rule. It was twice as long as the usual slide
> rule, so you could get 4-5 digit accuracy. Only one I have ever seen like
> it.

Were Picket slide rules the only ones made of *metal*??? I remember the
Pickets were a disgusting shade of yellow...

[Charles Richmond]

"Joe Pfeiffer" <pfei...@cs.nmsu.edu> wrote in message
news:1bzk5p2...@pfeifferfamily.net...

If you are "into" cylindrical, get a Curta calculator for your cylindrical
collection. :-) I have heard of private pilots using a Curta.

[Charles Richmond]

<hanc...@bbs.cpcn.com> wrote in message
news:bcd9cc16-c20b-4b41...@f17g2000vbz.googlegroups.com...

Why don't we have an "electronic" slide rule... with a vernier dial on it???
:-)

[Robin Vowels]

On Aug 22, 10:55 pm, Shmuel (Seymour J.) Metz
<spamt...@library.lspace.org.invalid> wrote:
> In <k115v603...@news3.newsguy.com>, on 08/21/2012

>    at 07:35 PM, "Joe Morris" <j.c.mor...@verizon.net> said:
>
> >H'mmm...I think that you must have been sending the output to a
> >printer with a 120-character line.
>
> No, just that the specific program was written for 120.
> RECFM=VBA,LRECL=125 will work fine going to a wider printer.

Except if the actual output record has more than 121 characters.

[Robin Vowels]

On Aug 20, 4:30 am, sc...@slp53.sl.home (Scott Lurndal) wrote:
> Robin Vowels <robin.vow...@gmail.com> writes:
> >On Aug 19, 12:02=A0am, jmfbahciv <See.ab...@aol.com> wrote:
>
> >> A good operator [I don't know how to explain this] took handful of cards,
> >> ruffled it in several different ways, knocked it on a hard surface and
> >> felt the sides (edges) of that deck.
>
> >That was standard practice.
> >Our card reader had an L-shaped chromed plate on which a card deck
> >was knocked sideways and up and down so as to get the cards
> >perfectly lined up, prior to placing them in the reader chute.
>
> Similar to this?
>
> http://digital.lib.umn.edu/IMAGES/reference/cb/cb000534.jpg
>
> This was the final generation of table-top card readers from
> Burroughs.   Had a tendency to Jam more than the older models.

Sort of. That one has two bent-up ledges. Ours had only one.
The ledges are rather short.
Also, it's designed for a left-hander.

[Christian Brunschen]

In article <k12pdf$g3u$1...@dont-email.me>,

... and to go full circle, there are free apps for mobiles that emulate
slide rules:

Android:
https://play.google.com/store/apps/details?id=com.ml32.sliderule
https://play.google.com/store/apps/details?id=nz.gen.geek_central.infinirule

iOS:
http://itunes.apple.com/us/app/pocket-slide-rule/id421890273?mt=8&ls=1

Best wishes,

// Christian

[Michael Black]

I thought they did, they were called "analog computers". You could then
use multi-turn pots with counter dials on them, or reduction drive dials
feeding single turn pots. Nowadays, one could even use cheap DMMs as the
readout(s), to get the extra digits. I seem to recall one analog computer
in one of the hobby magazines that included a magnifying glass over the
meter, but that might have been some other project.

Michael

[hanc...@bbs.cpcn.com]

On Aug 22, 10:06 am, "Charles Richmond" <numer...@aquaporin4.com>
wrote:
> <hanco...@bbs.cpcn.com> wrote in message

There's one on my desk.

From above, let's get some random numbers. We have 2.95 * 3.95.
Let's see if I got this right.

So I slide the C over so the left 1 is over the 295. But the 395 is
off the scale, so I use the right 1 over 295. I get 113 or 11.30.
Incorrect!

Try again. Oops, the 1 is over the 290, not 295. 11.65. Correct
calculator answer is 11.6525 .


Slide rule going back into the drawer.

[Charlie Gibbs]

In article <qf2638pcvqjgq38jo...@4ax.com>, ge...@ocis.net
(Gene Wirchenko) writes:

> On Sun, 19 Aug 2012 22:46:05 -0400, Michael Black <et...@ncf.ca>
> wrote:
>
>[snip]
>
>>And it's only in recent decades that it's become valued. The decades have
>>thinned out the heard, and enough time has passed that people regret
> ^^^^^
> Fortuitous typo!

Gather round like cattle, and you shall be herd.

--
/~\ cgi...@kltpzyxm.invalid (Charlie Gibbs)
\ / I'm really at ac.dekanfrus if you read it the right way.
X Top-posted messages will probably be ignored. See RFC1855.
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[Charlie Gibbs]

In article
<944772cf-288d-4e5f...@k3g2000vby.googlegroups.com>,
hanc...@bbs.cpcn.com (hancock4) writes:

> On Aug 20, 7:20 pm, "Joe Morris" <j.c.mor...@verizon.net> wrote:
>
>> Aneroid or mercury barometer?  If it was a mercury barometer then
>> the column would have had a scale next to it, with a vernier to
>> allow very precise measurement of the column height.
>
> Pretty sure it was mercury. I didn't know its age, but probably from
> the 1950s at the latest, maybe earlier, judging by the type style on
> the scales.
>
> We had to take both the pressure and temperature for our lab
> experiments. But the whole thing was pointless since the barometer
> was located in a corner which was much colder than the rest of the
> room, so it didn't really reflect our workbench. Further, we were
> kids and barely knew what we were doing.

I tried to make a mercury barometer in the chemistry lab. I took
a long length of glass tubing, melted one end shut, filled it with
mercury, and went to stand it up. Too bad I didn't have enough
people supporting it as I raised it - the tube broke. I spent
a lot more time than would now be considered safe, crawling around
on my hands and knees gathering up the spilt mercury by sliding
paper towels under the little blobs that were all over the floor.

> Chemistry was not my thing. Moles. Avogadros' number. Ions.
> Akaline. Acids. Reagants (NY State Board of).

Old chemists never die, they just fail to react.

[Charlie Gibbs]

The first machine I worked on had a 120-position printer.
If you wanted to be really cheap, you could order one with
a 96-position printer. It looked exactly the same as a
120- or 132-position printer, except that a lot of the
hammers (and associated electronics) were omitted.

[Joe Pfeiffer]

My metal slide rule is a Pickett; it's sort of an ivory color. And...
oh, no... it's corroded since the last time I looked at it... locked up
solid...

[hanc...@bbs.cpcn.com]

On Aug 22, 12:42 pm, Joe Pfeiffer <pfeif...@cs.nmsu.edu> wrote:
> My metal slide rule is a Pickett; it's sort of an ivory color.
 And...
> oh, no...  it's corroded since the last time I looked at it... locked up
> solid.

When I was attemping the above problem, the center stick moved when I
moved the cursor, the whole thing was kind of slippery and hard to be
precise. I presume the high grade models were more 'controlled'.

Also, I wonder if the high grade models were perhaps an inch or two
longer, to give slightly more precision. The "C" scale on the
Sterling unit measured 9 7/8 inches from the '1" to "1". The total
rule measured 11 inches edge to edge.

[grey...@mail.com]

Bring lots of cash.

--
maus
.
.
...

[Joe Pfeiffer]

The good ones were bamboo. You could adjust the tension so you'd get
*just* the degree of slipperiness you wanted.

[Joe Pfeiffer]

I would love to have a Curta. Not going to happen until I hit the
lottery...

[Dave Garland]

Now, quick, tell us whether those final two digits actually mean
something, or are just noise. How about the second decimal place in
the answer?

Dave

[Dave Garland]

Most general-purpose (VOM/VTVM) type meters had mirrored bands on the
scale, and you'd eliminate parallax by moving your head so that the
reflection of the pointer was hidden by the pointer itself.

Seems to me that any D'Arsonval meter that was accurate enough to
warrant putting a magnifier on it, would have been fitted with a
larger scale at the factory ("magnifying" the scale by making the
pointer and scale longer) and sold at a higher price in the first
place. I have, however, seen (mechanical) radio tuning dials that
used magnifiers to increase the resolution without making the front
panel excessively large.

[Dave Garland]

On 8/22/2012 1:13 PM, hanc...@bbs.cpcn.com wrote:
> On Aug 22, 12:42 pm, Joe Pfeiffer <pfeif...@cs.nmsu.edu> wrote:
> > My metal slide rule is a Pickett; it's sort of an ivory color.
> And...
>> oh, no... it's corroded since the last time I looked at it... locked up
>> solid.
>
> When I was attemping the above problem, the center stick moved when I
> moved the cursor, the whole thing was kind of slippery and hard to be
> precise. I presume the high grade models were more 'controlled'.

Most of the metal and bamboo rules had end brackets that were
adjustable, both to realign the ends, and to adjust the pressure. A
good slide rule had sort of a viscous feel when you moved the slide,
and didn't overshoot.

I can't remember if rubbing paraffin on the slide edges helped with
plastic ones, but it might.

> Also, I wonder if the high grade models were perhaps an inch or two
> longer, to give slightly more precision. The "C" scale on the
> Sterling unit measured 9 7/8 inches from the '1" to "1". The total
> rule measured 11 inches edge to edge.

"10 inch" was a standard size, both for the cheapo Sterlings and the
more expensive K&E, Pickett, Post, Hemmi, etc. The more expensive
rules had thinner marking lines, spring-loaded cursors, and usually
more scales.

[hanc...@bbs.cpcn.com]

On Aug 22, 3:42 pm, Dave Garland <dave.garl...@wizinfo.com> wrote:

> > Try again.  Oops, the 1 is over the 290, not 295.  11.65.  Correct
> > calculator answer is 11.6525 .
>
> Now, quick, tell us whether those final two digits actually mean
> something, or are just noise.  How about the second decimal place in
> the answer?

There were rules regarding 'significant digits' and decimal points,
but I forgot them.

Like I said, the slide went back to the drawer (way in the back of the
drawer).. <g>

[Ahem A Rivet's Shot]

On Wed, 22 Aug 2012 15:05:32 -0500
Dave Garland <dave.g...@wizinfo.com> wrote:

> "10 inch" was a standard size, both for the cheapo Sterlings and the
> more expensive K&E, Pickett, Post, Hemmi, etc. The more expensive
> rules had thinner marking lines, spring-loaded cursors, and usually
> more scales.

There were rules without spring loaded cursors ? Even my cheap
school standard 6" had a spring loaded cursor, as did the rather more
expensive British Thornton 10" duplex that replaced it.

--
Steve O'Hara-Smith | Directable Mirror Arrays
C:>WIN | A better way to focus the sun
The computer obeys and wins. | licences available see
You lose and Bill collects. | http://www.sohara.org/

[Dave Garland]

On 8/22/2012 3:28 PM, hanc...@bbs.cpcn.com wrote:
> On Aug 22, 3:42 pm, Dave Garland <dave.garl...@wizinfo.com> wrote:
>
>>> Try again. Oops, the 1 is over the 290, not 295. 11.65. Correct
>>> calculator answer is 11.6525 .
>>
>> Now, quick, tell us whether those final two digits actually mean
>> something, or are just noise. How about the second decimal place in
>> the answer?
>
> There were rules regarding 'significant digits' and decimal points,
> but I forgot them.

That's my point. The "correct" answer to 2.95 * 3.95 is 11.7.
Additional decimal places mean nothing.

2.95 does not imply 2.95000

> Like I said, the slide went back to the drawer (way in the back of the
> drawer).. <g>

Whether you do it with a slide, a calculator, or a computer.
Calculators just make it easier to forget.

[glen herrmannsfeldt]

In comp.lang.pl1 Dave Garland <dave.g...@wizinfo.com> wrote:
> On 8/22/2012 3:28 PM, hanc...@bbs.cpcn.com wrote:
>> On Aug 22, 3:42 pm, Dave Garland <dave.garl...@wizinfo.com> wrote:

(snip)

>>>> Try again. Oops, the 1 is over the 290, not 295. 11.65. Correct
>>>> calculator answer is 11.6525 .

>>> Now, quick, tell us whether those final two digits actually mean
>>> something, or are just noise. How about the second decimal place in
>>> the answer?

>> There were rules regarding 'significant digits' and decimal points,
>> but I forgot them.

> That's my point. The "correct" answer to 2.95 * 3.95 is 11.7.
> Additional decimal places mean nothing.

But this is the PL/I newsgroup, and so the PL/I rules for multiply
should apply. There must be some newsgroup for discussing
calculators. (Note that those are fixed point values in PL/I.)

> 2.95 does not imply 2.95000

It also doesn't imply 2.95e0.

I do agree that in the floating point case one should expect
approximate answers. Don't forget some of the Cray machines
where fast, approximate answers were considered better than
slow exact answers. There was even one where multiply wasn't
commutative.

-- glen

[Dave Garland]

On 8/22/2012 4:16 PM, Ahem A Rivet's Shot wrote:
> On Wed, 22 Aug 2012 15:05:32 -0500
> Dave Garland <dave.g...@wizinfo.com> wrote:
>
>> "10 inch" was a standard size, both for the cheapo Sterlings and the
>> more expensive K&E, Pickett, Post, Hemmi, etc. The more expensive
>> rules had thinner marking lines, spring-loaded cursors, and usually
>> more scales.
>
> There were rules without spring loaded cursors ? Even my cheap
> school standard 6" had a spring loaded cursor, as did the rather more
> expensive British Thornton 10" duplex that replaced it.
>

A few. I have a single-sided (tables of constants and weights of
metals on the back) 8" wooden rule that was probably an advertising
giveaway and doesn't have any springs in the cursor. Though the
cursor window is mounted on a thin metal frame that's sort of "C"
shaped in cross-section, fitting into grooves along the top and bottom
edges, and the metal frame itself may act like a spring.

The plastic log-log Sterling that I have does have springs and is
actually rather nice, but I think it was one of their fancier models.

[Robin Vowels]

On Aug 23, 8:18 am, Dave Garland <dave.garl...@wizinfo.com> wrote:

> On 8/22/2012 3:28 PM, hanco...@bbs.cpcn.com wrote:
>
> > On Aug 22, 3:42 pm, Dave Garland <dave.garl...@wizinfo.com> wrote:
>
> >>> Try again.  Oops, the 1 is over the 290, not 295.  11.65.  Correct
> >>> calculator answer is 11.6525 .
>
> >> Now, quick, tell us whether those final two digits actually mean
> >> something, or are just noise.  How about the second decimal place in
> >> the answer?
>
> > There were rules regarding 'significant digits' and decimal points,
> > but I forgot them.
>
> That's my point.  The "correct" answer to 2.95 * 3.95 is 11.7.

Get a new slide rule.
That's not the answer my slide rule gives.

[Michael Black]

Am I thinking of something else? I remember Wayne Green advertising some
sort of cylindrical calculator in CQ or maybe 73 in the late fifties or
early sixties. The original reason he imported them was for use in road
rallies (which were happeing in the US at the time, all those imported
Porsches and other sports cars being a reason to import car rallies) where
you needed to make calculations, since it wasn't just about speed. I can
picture a cylindrical calculator.

On the other hand, wikipedia says they sold for about $125, which seems
kind of expensive to be sold in the back of a radio magazine.

Michael

[Dave Garland]

On 8/22/2012 5:32 PM, glen herrmannsfeldt wrote:
> In comp.lang.pl1 Dave Garland <dave.g...@wizinfo.com> wrote:
>> On 8/22/2012 3:28 PM, hanc...@bbs.cpcn.com wrote:
>>> On Aug 22, 3:42 pm, Dave Garland <dave.garl...@wizinfo.com> wrote:
>
> (snip)
>>>>> Try again. Oops, the 1 is over the 290, not 295. 11.65. Correct
>>>>> calculator answer is 11.6525 .
>
>>>> Now, quick, tell us whether those final two digits actually mean
>>>> something, or are just noise. How about the second decimal place in
>>>> the answer?
>
>>> There were rules regarding 'significant digits' and decimal points,
>>> but I forgot them.
>
>> That's my point. The "correct" answer to 2.95 * 3.95 is 11.7.
>> Additional decimal places mean nothing.
>
> But this is the PL/I newsgroup, and so the PL/I rules for multiply
> should apply. There must be some newsgroup for discussing
> calculators. (Note that those are fixed point values in PL/I.)
>
>> 2.95 does not imply 2.95000
>
> It also doesn't imply 2.95e0.

It usually implies (or did, way back when I was in engineering school)
that the number could not be specified with any more precision, except
perhaps by saying "2.95+/-0.005". It isn't a matter of how PL/I or
floating point handle the calculation, it's a matter of "garbage in".

[Dave Garland]

Curtas were indeed popular with rally navigators in that
pre-electronic digital era. They looked sort of like a pepper mill
with a crank on top and little slides on the sides. Yeah, it was a
little pricey for advertising in the back of a radio magazine, but
Wayne Green owned the magazine so the economics probably worked out.

Looks like ones in working order go for $1-2K on eBay. That's
actually cheaper than I expected.

[Joe Pfeiffer]

Yes, we're thinking of the same thing. I was doing some road rallies in
the mid-1970s, and wanted one at the time for that purpose, and it seems
like the price is similar. I couldn't afford one then, and now:

http://www.ebay.com/sch/i.html?_trksid=p5197.m570.l1311&_nkw=curta+calculator&_sacat=0

Note that the Curta was a mechanical calculator; about the only thing it
had in common with my cylindrical slide rule is they're both round.

[Walter Bushell]

In article <k13lsb$7kb$1...@dont-email.me>,

Perhaps students should be forced to learn slide rules, for that
reason and because the idea of multiplying by rubbing two sticks
together is so interesting.

--
This space unintentionally left blank.

[Peter Flass]

On 8/22/2012 10:12 AM, Charles Richmond wrote:
> "Peter Flass" <Peter...@Yahoo.com> wrote in message
> news:k0udjk$3g5$1...@dont-email.me...
>> On 8/20/2012 1:49 PM, hanc...@bbs.cpcn.com wrote:
>>>
>>> [snip...] [snip...] [snip...]
>>>
>>> Some circular and linear slide rules were made of inexpensive
>>> materials and distributed by companies as advertising novelties. For
>>> instance, one scale would show an application and the other scale,
>>> once matched to it, would show the recommended product for that
>>> application.
>>>
>>
>> Yes, I remember those. These days they'd probably have to distribute
>> some sort of electronic calculator-like device to connect with their
>> customers. It's be cheap enough though.
>>
>
> These days, they distribute "free apps" for your iPhone, iPad, iPod
> Touch, or Android phone or tablet. Usually these things are in the
> regular app store.
>

"Free" as in "loaded with advertising." I tried a couple of "free" iPad
calculators and promptly deleted them. For $2.95 I'll buy an "Ad-free"
one, once I have time to pick one.


--
Pete

[Peter Flass]

On 8/22/2012 10:14 AM, Charles Richmond wrote:
> "Warren Adams" <ada...@hiwaay.net> wrote in message
> news:5rKdncTEfo6bT6_N...@posted.hiwaay2...

>> On 8/19/2012 6:51 PM, Peter Flass wrote:
>>> On 8/19/2012 3:36 PM, hanc...@bbs.cpcn.com wrote:
>>>> On Aug 18, 6:48 pm, "Joe Morris" <j.c.mor...@verizon.net> wrote:
>>>>
>>>>> The meaning of "accurate" depends on several criteria, including how
>>>>> many
>>>>> decimal places are required.
>>>>
>>>> Correct. If memory serves, a slide rule was only good for roughly
>>>> three digit accuracy. Even simple BASIC gave six digit accuracy. Of
>>>> course, a slide rule was a lot more portable than a Teletype. <g> In
>>>> the early 1970s, it was far cheaper ($3) than an electronic calculator
>>>> ($100+). But calculators quickly came down in price and improved in
>>>> functionality making the slide rule obsolete by the late 1970s.
>>>
>>> I think a good slide rule cost a lot more than $3, even in 1970.
>>>
>> I purchased my Post slide rule in 1960. I think it was about $25.
>> I agree with the ~3 digit accuracy. Except that at work mid 60's, we
>> had a "double precision" slide rule. It was twice as long as the
>> usual slide rule, so you could get 4-5 digit accuracy. Only one I
>> have ever seen like it.
>

> Were Picket slide rules the only ones made of *metal*??? I remember the
> Pickets were a disgusting shade of yellow...
>

K&E made a good sliderule, AIR.



--
Pete

[jmfbahciv]

Simon Turner wrote:
> On 18 Aug, in article
> <PM0004C78...@ac8409ec.ipt.aol.com> See....@aol.com
> "jmfbahciv" wrote:
>
>> Simon Turner wrote:
>> > On 17 Aug, in article
>> > <PM0004C77...@ac83b7da.ipt.aol.com>
>> > See....@aol.com "jmfbahciv" wrote:
>> >
>> >> If you don't read replies to speedo's posts, then you have missed some
>> >> very interesting posts.
>> >
>> > I'm well aware of that, and I used to just kill speedo's posts so I
>> > could try to pick out the worthwhile replies; but I found it impossible
>> > to read the replies without also reading (some of) what he had written,
>>
>> I just skip it while I'm scanning the post.
>
> I found I couldn't. Some part of it would catch my eye and I'd find my
> blood pressure rising.

Sounds like a tool to use to learn how to relax. ;-)

>
>> IMO, Morten's write-ups are worth the stress. He would not have done
>> some of them if I hadn't talked with speedo.
>
> That would make an interesting mod to my script: look for long posts by
> non-Rods (esp. Morten) that have a high ratio of new material to quoted
> stuff, and don't mark them as read. Hmmmmm.


Even the short ones. I don't think I've ever seen a post from
Morten that didn't have something new and interesting to me.

>
> (I find wading through 200 lines of quoted material just to find two
> lines of new stuff annoying, too; I wish more people would trim before
> replying!

I have a difficult time trimming because I can't decide which ones aren't
important. But I don't read the angle-bracketed lines unless I need
to refresh my memory about the subject.

> But the old customs are dying out: there's one group I skim
> where the local netiquette has it that trimming posts before replying is
> a Bad Thing, because it makes you look as though you're trying to hide
> something. They have a lot of rather unpleasant arguments in that
> group, which has obviously skewed perceptions over the years.)

Sounds like they need some retraining.

>
>> > Indeed. I'm alarmed by the amount I can't recall about software I wrote
>> > only a few years ago...
>>
>> <grin> TW couldn't remember what he wrote yesterday. OTOH, JMF remembered
>> every line of code and why it was written the way it was written.
>
> Would that I could have JMF's memory.

There was one programmer so used to his ability to recall code that the
programmer expected him to recall someone else's code written after Jim
stopped working for the PDP-10 product line.

> Even with my (in)famous reams of
> comments I still sometimes find myself wondering why I did something in
> a particular way; and to cap it all, recently I accepted a minor feature
> request to some old software and actually got part of the way into the
> job before realising that I'd already implemented the feature when I
> first wrote the code six years ago, but the user hadn't spotted it. 8-/

Did you sit on it and then present after the equivalent time of
implementation? :-) That kind of thing was covered by our writers
so that even the most bizarre user interface would be documented.
A few writers would read our listings to find all the error messages.

/BAH

[jmfbahciv]

rectifier wrote:
> "Shmuel (Seymour J.)Metz" <spam...@library.lspace.org.invalid> wrote in
> message news:50322c8b$20$fuzhry+tra$mr2...@news.patriot.net...
>> In <Pine.LNX.4.64.12...@darkstar.example.net>, on
>> 08/19/2012
>> at 09:35 PM, Michael Black <et...@ncf.ca> said:
>>
>>>I think you could get cheap ones, probably for learning to use
>>>one in high school,
>>
>> In my HS a good slide rule was a status symbol. I don't know of any
>> classmate that had an el cheapo slipstick.
>
> That says more about your HS than anything else.

I'm jealous. I would have loved to go to a school like that.

/BAH

[jmfbahciv]

John Levine wrote:
>>>> I believe that the PDP-8 used discrete transistors.
>>>>
>>> Yes, and I slipped. That should have been "minicomputer". I do know
>>> the difference.
>>>
>>
>>About the power of a 4004 though?
>
> No, the PDP-8 was considerably faster. It was 12 bit parallel (other
> than the later 8/S) and had a 1.5us cycle time, so it could do a 12
> bit add in 3us. A 4004 had a 10us instruction time.
>
> For applications where 12 bits was enough, which included a lot of
> data aquisition and control, the -8 was quite fast.

Another reason people liked the PDP-8 is because it could sit on
a dirty and jittering machine shop floor and just keep working.

/BAH

[jmfbahciv]

Peter Flass wrote:
> On 8/20/2012 9:36 AM, jmfbahciv wrote:
>> Shmuel (Seymour J.) Metz wrote:
>>> In <PM0004C79...@users-ibook-g4-6.unknown.dom>, on 08/19/2012
>>> at 02:12 PM, jmfbahciv <See....@aol.com> said:
>>>
>>>> Doing hardware instructions.
>>>
>>> Hardware instructions not called system call. Again, it's "system
>>> call" that is the neologism and a system call is a software artifact,
>>> not an instruction.
>>>
>> IIRC, LIGHTS UUO isn't software. I don't seem to be able to find
>> my cheat sheets.
>>
>> ISTR, being able to hand the monitor a list of hardware instructions
>> but I can't remember the details this morning.
>>
>
>
> I'm not a PDP-10ian, but wasn't UUO "unassigned user operation?" That
> is an unassigned opcode that would trap to the monitor if executed?
> That much was hardware. What the monitor did with it was software.
>
>
I've tried to find the documentation for this. I don't have any old
enough. I recall UUOs and MUUOs. I don't remember enough to discuss
them. My apologies.

/BAH

[Peter Flass]

I had a nice Pickett with a case in college. A few years ago, in the
eternal struggle between the family hoarder and the family cleaner-outer
I sold it in a garage sale. A couple of years later, in a fit of
regret, I picked up one, unfortunately the cheap plastic model, in
another garage sale. Oh well, when civilization crumbles and you can no
longer get batteries for your fancy calculators, I'm prepared.

--
Pete

[Peter Flass]

On 8/22/2012 10:05 AM, glen herrmannsfeldt wrote:
> In comp.lang.pl1 Peter Flass <Peter...@yahoo.com> wrote:
>
> (snip, I wrote)
>
>>> WTO 'IEM3896I SYSPRINT BLOCKSIZE IS NOT OF FORM 4 +N*125',
>
> (snip)
>>> But why does the BLKSIZE have to be 4*N+125? The whole idea of VB is
>>> that you can write different length records. Even if the compiler
>>> only writes 121+4, it should still allow other lengths.
>
>> In this case BLKSIZE can be anything >= 129 (one record). [that's 4+N
>> above, you wrote 4*N, typo?) 4 btes for BLKSIZE, 4 for RECSIZE, 1 for
>> carriage control, and up to 120 bytes of data.
>
> Yes I exchanged the + and *. Must be typing too fast.
>
> In FB, the BLKSIZE is supposed to be an integer multiple of LRECL.
> But for VB, why should BLKSIZE be 4 plus an integer multiple
> of LRECL?
>

Doesn't have to be, as long as it's bigger than LRECL+4. You'd just
pick a convenient size, considering track size, etc.


--
Pete

[Joe Morris]

<hanc...@bbs.cpcn.com> wrote:

>When I was attemping the above problem, the center stick moved when I
>moved the cursor, the whole thing was kind of slippery and hard to be
>precise. I presume the high grade models were more 'controlled'.

Decent slide rules were designed with screws in the end-pieces so that you
could adjust the pressure exerted on the slide.

H'mmm...you got my curiosity up. I just now went to the basement and dug up
my old Pickett (more correctly, "Pickett & Eckel") model 1020-ES. Not big;
the scales are fractionally less than 10", and the entire rule is only
~1.25" high. Scales are C, D, L, CI, CIF, CF, and DF on one side, C, D, S,
T, ST, A, B, K, and DI on the other. Both of the endpieces are adjustable.

One characteristic of this slide rule that you won't find on a calculator:
it came with a genuine leather case (stamped "California Saddle Leather").
Both the slide rule and the case are in amazingly good condition other than
a tiny (and hard to see) crack in one corner of the cursor.

Joe