TWGS vs. ZipChip

Nathan Mates

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Oct 28, 1992, 5:10:01 PM10/28/92

to

I'm going to be buying a Zip Chip or a TWGS sometime in the near future,
and I would like a recommendation on one of the two. So far, the major
characteristics of the two SEEM to be: (from what I've read)

TWGS- User upgradeable easier than Zip
Zip - Cheaper, larger cache possible

Is this really the case? If anyone has anything to dispute these two,
please email me.

(If this is a FAQ, oooooops!)

Thanks in Advance

Nathan Mates
nat...@cco.caltech.edu

Joe Kohn

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Oct 29, 1992, 2:27:10 PM10/29/92

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Let me put it this way. A year, year and a half ago, ZIP Technology came to
my local user group to give a demo of the ZIPGS. A number of user group
members purchased ZipGS at that meeting. As it turned out, 70% of all the
Zips sold had to be returned, as they did not work!

On the other hand, I have had a TransWarpGS for several years, and have had
no problems with it.

Joe Kohn

That Ian Guy

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Oct 29, 1992, 7:12:41 PM10/29/92

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In article <BwwE1...@well.sf.ca.us> jo...@well.sf.ca.us (Joe Kohn) writes:
>In article <1cn33p...@gap.caltech.edu> owl.caltech.edu!nathan (Nathan Mates) writes:
>>I'm going to be buying a Zip Chip or a TWGS sometime in the near future,
>>and I would like a recommendation on one of the two. So far, the major
>

>Let me put it this way. A year, year and a half ago, ZIP Technology came to
>my local user group to give a demo of the ZIPGS. A number of user group
>members purchased ZipGS at that meeting. As it turned out, 70% of all the
>Zips sold had to be returned, as they did not work!

I have had two different Zips in my IIgs over the past 2 years and have had
zero problems with them (the first was on extended loan from a friend with
more than one GS; the second I bought myself becuase I was so impressed).
The Zip has many technical advantages over the Transwarp: the Zip draws 120
ma and the Transwarp draws 1.2 amps (1200 ma, 10 times more power!, and the
corresponding heat increase). The Zip coprocesses I/O, which was graphically
illustrated when MODZap was version 00.20 and ran on Zipped machines but
wouldn't run correctly on Transwarped ones. Basically, this means all I/O
intensive operations (music, graphics, serial, etc) will be faster on a Zip
than a comparable TWGS. The Zip also is a much smaller board with far fewer
components and after the usual initial problems is a much more reliable
board in the long run than a TWGS.

As a final note, I talked to someone recently who took their TWGS out of their
computer, shot it with a shotgun, and ordered a Zip...

>Joe Kohn

--
Ian Schmidt: irs...@iastate.edu or aol.com, BITNET: twbv4@isuvax
=--=-=-=-=-=-=-=-=-=Real Change in '92: Vote Ross Perot!-=-=-=-=-=-=-=-=-=-=-=-
"I have no experience running up a four trillion dollar debt" - Ross Perot
Ask me about the GS<>IRC demo...better yet ask da...@ccwf.cc.utexas.edu!

Todd P. Whitesel

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Oct 30, 1992, 5:48:42 AM10/30/92

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My Zip experience has been that while the Zip is a superior design nearly all
modern standards, both it and the RamFast "D" card have more noise sensitivity
than "hi power" designs like the TWGS and the RamFast "C".

Zip seems to be having about pretty even luck, according to the reports I've
seen. Lots of people have no problems and never pipe up. Lots of people never
seem to be able to get a ZipGS to work in their system. Still others have to
send it back once or twice before they get one that works.

What Zip needs to do is get their hands on some of the problem machines and
figure out what is really going on with a logic analyzer. It has got to be
some noise characteristic that's specific to certain manufacturing runs of
the IIgs motherboard. (Supposedly the ROM 03 always like the Zip; unfortunately
I haven't seen enough confirmation or evidence to the contrary about this.)

Todd Whitesel
toddpw @ cco.caltech.edu

Joe Kohn

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Oct 30, 1992, 12:01:19 PM10/30/92

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OK, Ian. I'll ask. What's the GS<>IRC demo?

If you were involved with it, I want it!

Regarding the ZIP/TWGS question...

I have spoken to many people who are very very happy with their ZIP's.
Unfortunately, I've also spoken to many people who are outraged at the fact
that they have had to send in their ZIP GS several times before getting one
that works. If people want to buy ZIP GS, I just think it's important that
people realize that ZIP's track record has been spotty, to say the least.

Again, I have had a TWGS since almost the day they were released, and have
been very very happy. I am not an apologist for AE, and I don't like the 900
tech support, but, IHMO, the TWGS is a great product.

Joe Kohn

Paul Benson

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Oct 30, 1992, 3:44:05 PM10/30/92

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In <Bwy1y...@well.sf.ca.us> Joe Kohn writes:
>I have spoken to many people who are very very happy with their ZIP's.
>Unfortunately, I've also spoken to many people who are outraged at the fact
>that they have had to send in their ZIP GS several times before getting one
>that works.

I have a TWGS and have had little trouble with it (knock, knock). I agree
with Joe, I rarely hear people complaining about the TWGS as with the Zip.
The TWGS can go the full 14MHz, the Zip is hindered (at least for now).
I always hear people suggesting to try running some program at xx% of
speed if they have a Zip because the Zip messes up the program. I have
never had to slow down a program with my TWGS because it would not run.
There are a few things I wish the TWGS did that the Zip does, such as
lower power dissipation and the faster screen drawing, but apparently
they broke some rules and that is why some things are just not quite
right about the boards. However, I'd probably recommend a Zip to a friend,
since Zip apparently does have a decent return policy, and you'll eventually
get one that works. I'd rather spend my money on a company that is
supporting us, and the Zip is certainly not a terrible piece of hardware.

Pauley
GEnie: P.Benson1

Mark Munson

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Oct 30, 1992, 5:29:16 PM10/30/92

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I had a 7 MHz TransWarp in my GS. It was replaced with a 9 MHz ZipGS with 32K RAM
Cache. I havn't had trouble with either card, but I like the Zip better due to
it's higher speed and better control panel.

The Transwarp would only let me run at 1, 2.6, or 7 MHz. While the ZipGS will
let me run at a variety of speeds. I've found that running my new GS desktop
applications at 0.6 MHz to be real handy for following the execution of the
program.

A prior author mentioned that the Zip was hindered from going up to 14 MHz. Is
this really true? I was under the impression that the Zip was easier to upgrade
if you already had a 9+ MHz version, becuase the CPU was already being driven
at ~5.5 Volts. The 7 MHz Zip cards don't have the extra transistor and resistors
that were needed to boost the CPU voltage (although they can be added to the 7
MHz version circuit card which has room for them).

My ( MHz Zip actually has a 7 MHz rated 65C816 chip installed. I was let to
believe that all I needed to go faster was a 14 MHz rated 65C816, faster/larger
RAM CACHE chips, and some faster crystals.

Who has the fastest ZipGS, and whay types of parts are you using?

[MGM]

the Weasel...

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Oct 30, 1992, 6:07:36 PM10/30/92

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jo...@well.sf.ca.us (Joe Kohn) writes:

>Regarding the ZIP/TWGS question...

>that works. If people want to buy ZIP GS, I just think it's important that
>people realize that ZIP's track record has been spotty, to say the least.

I believe that most of the problems concerning the ZipGS was with the faster
boards like the 9mhz and faster... Personally, I've heard almost nothing
about the 7 or 8mhz boards. I have a 8mhz for a year and a half with no
problems. =)

>Again, I have had a TWGS since almost the day they were released, and have
>been very very happy. I am not an apologist for AE, and I don't like the 900
>tech support, but, IHMO, the TWGS is a great product.

One feature of the TWGS that I envy is the built in CDA. I wish my Zip
could be accesed like the TWGS anytime I wanted to. I hate booting GS/OS
or even running Zippy to just change the speed.

>Joe Kohn

---Mike

Gregory Ross Thompson

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Oct 30, 1992, 3:45:19 PM10/30/92

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jo...@well.sf.ca.us (Joe Kohn) writes:
> Let me put it this way. A year, year and a half ago, ZIP Technology came to
> my local user group to give a demo of the ZIPGS. A number of user group
> members purchased ZipGS at that meeting. As it turned out, 70% of all the
> Zips sold had to be returned, as they did not work!

Hold on. I bought a ZipGS 9/32 a little over a year ago. I have
not had a single crash that I've attributed to the Zip. PLEASE don't
interpret Joe's comment as "the Zip sucks". The Zip doesn't suck.
It's very user upgradable. I've bumped mine up to a 64k cache, and
will probably pump it up to 12MHz whenever I have the money/motivation
to do it (about $100).

> On the other hand, I have had a TransWarpGS for several years, and have had
> no problems with it.

Many people have also had Zips, and not had problems. Both boards
are good. Both have advantages and disadvantages.

> Joe Kohn

-Greg
InterNet: gre...@cmu.edu
or: gt...@andrew.cmu.edu
BITNet : R746GT0T@CMCCVB
AOL : GRThompson

Todd P. Whitesel

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Oct 31, 1992, 8:33:05 AM10/31/92

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jo...@well.sf.ca.us (Joe Kohn) writes:

>I have spoken to many people who are very very happy with their ZIP's.
>Unfortunately, I've also spoken to many people who are outraged at the fact
>that they have had to send in their ZIP GS several times before getting one
>that works. If people want to buy ZIP GS, I just think it's important that
>people realize that ZIP's track record has been spotty, to say the least.

I don't intend to argue with this, but I do want to express the opinion that
Zip is not totally at fault. The chances for success of a ZipGS installation
has proven to be overwhelmingly dependent on the system it's added to.
Why else would the major classes of Zip users be people who have never had
problems, and people who have had lots of problems? Zip having a super-high
failure rate simply doesn't make sense -- it would have to hit everyone evenly,
and their design is too simple to exhibit the complexity-failure problems
that a good number of TWGS's have had.

If anybody lives in the LA area (near Culver City) and has had problems with
more than one Zip, AND you can spare the time, it might not be such a bad
idea to offer to bring your IIgs down to their office and let them figure out
why it doesn't work. I am willing to bet that Zip will discover a noise
characteristic that only exists on certain production runs of IIgs's, and
that it is what is responsible for a lot of their "rejects".

Drew of CVT has found that the RamFast rev D board has some noise sensitivity
problems in the DRAM circuit, which causes the board to be more "zappable" in
some systems than others. The bizarre part is, I've never had a problem with
the Zip that wasn't finally traced to a specific cause (usually a goof on my
part), but my IIgs has eaten two RamFast D boards and is back to using the
original Rev C that never dies. Apparently, this same phenomenon is why CVT
cannot recommend the Rev D board to //e users -- the noise characteristic in
a //e is a lot harder to filter out than the one in most IIgs's. But in some
IIgs's, it appears to sometimes be too much for today's "low power" designs.

What is needed is a "compromise" design that uses older high power chips for
the noise sensitive logic, and modern low-power stuff for the rest. State
of the art boards have to deal with this and problems that are far weirder.
One of my friends has been spending the last few months of his life getting
an R4000 board designed, and while some of the problems require lots of EE
theory (plus some wave physics!) to solve, he griped yesterday about how he
just wasted a week because "the last board couldn't do two bus transfers back
to back, but the R4000 can" ... funny, this is why every Zip has those slot
speed settings. The reason you never have to slow the TWGS down is because
the TWGS does it for you whether you need it or not.

Zip did not break any rules that were written. Zip tested the bounds of what
was left unsaid. Things like AppleTalk and ProTerm have had to suffer because
they didn't expect to be accelerated as much as they have been. If I didn't
want to have to crank my Zip down to x% whenever I run ProTerm I would just
set slot 2 to Normal and forget about it. But I like being able to get it to
run as fast as it will let me, rather than not having any choice as to how
fast it is.

Todd P. Whitesel

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Oct 31, 1992, 8:45:05 AM10/31/92

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mmu...@animal.es.com (Mark Munson) writes:

>A prior author mentioned that the Zip was hindered from going up to 14 MHz. Is
>this really true? I was under the impression that the Zip was easier to upgrade
>if you already had a 9+ MHz version, becuase the CPU was already being driven
>at ~5.5 Volts.

As far as I know, no shipped board has ever had the voltage booster active or
even installed. Zip does not pump the voltage on high speed boards they sell;
they hand-pick chips that can be tricked into operating above spec and use them
(that's why the printed speed rating doesn't match the clock speed you know
it's getting).

The deal with 14 mhz is that the original cache controller ASIC has some slow
paths in it that couldn't go much faster than 12.4 mhz (or at least that seems
to be the consistent figure). The modification that Zip is charging through
the nose for (and it's not exactly a simple modification) is to bypass parts
of the ASIC with 74F or some other fast logic parts, so that the board can run
at 14+ (I forget what the new maximum is). This appears to be specific to the
Sanyo, because Zip's original tests showed that the ASIC would let you go up
to 20 mhz -- when a CPU that could handle it was available.

>My ( MHz Zip actually has a 7 MHz rated 65C816 chip installed. I was let to
>believe that all I needed to go faster was a 14 MHz rated 65C816, faster/larger
>RAM CACHE chips, and some faster crystals.

Up to 12.4 mhz, that _is_ all you need. I think Zip was caught off guard by
this 12.4 requirement also. They've recovered with full capitalistic spirit
intact, though... at this point, with all the returns and problems (which,
remember, I don't think are quality control problems on Zip's part but really
information they aren't aware of), they probably need the money.

Joe Kohn

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Oct 31, 1992, 1:20:29 PM10/31/92

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To: Greg Thompson
Re: Zip vs TWGS

You hold on, Greg. You even quoted me. I said 70% of the people at the
Gravenstein Apple IIGS User Group that purchased Zips had to return them as
they didn't work.

Subtracting 70% from 100% gives you 30%. So, 30% of the people that
purchased Zips in my user group got ones that worked right out of the box.

That is a fact. And, you can't argue with facts.

Joe Kohn

Jawaid Bazyar

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Oct 31, 1992, 6:17:38 PM10/31/92

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jo...@well.sf.ca.us (Joe Kohn) writes:

Sure you can. Is it possible these people bent the pins of the connector
as they installed them? I, as another, have never had a problem with my
Zip except one, which was my fault (I moved my computer across the country
about 6 times in as many months- in the back of a loud and rumbly Mustang-
a solder joint on the crystal broke from the vibrations). Ever since
I got my 9/64 upgrade, not a single problem. None. Zip. :) Zero.
I know Many other people with Zips who have also had no problems.

Seriously, Joe, if you took that same user's group and had them
install new carburetors on their cars, when 70% of them failed to
operate correctly would you blame the carburetor?

I'm not trying to be insulting. I'm just saying that _I've_ had
problems getting the damn connector in correctly, and I've been
pulling and plugging chips for 10 years.

--
Jawaid Bazyar | Ask me about the GNO Multitasking Environment
Procyon, Inc. | for the Apple IIgs!
baz...@cs.uiuc.edu | P.O Box 620334
--Apple II Forever!-- | Littleton, CO 80162-0334 (303) 933-4649

Reade Glyn Devin

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Nov 1, 1992, 1:31:22 AM11/1/92

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As I had e-mailed the original poster of this thread, I _have_ had
problems with TWGS. About 18 months ago I ordered one from Roger
Coats and I couldn't even get to the first welcome screen (nor the
TWGS error program). I sent it back for a replacement. _That_
didn't work as there were problems with the scheduler (??). I sent
it to AE. About three times I sent it to AE and got a different
board back each time (identifying marks on the PCB). Finally I
gave up on TWGS and exchanged it for a Zip 9/32. Fantastic. No
problems at all.

I'm using ROM 01, AEDL 2400, iS FPE, Zip 9/32, Ramkeeper w/ GSRam+ 3Meg
and apple 1Meg.

Yes, I realize that this doesn't in general make TWGS worthless and
Zip problem free, but I figured it was time to give Zip some support
on this thread... By the way, that was a different problem
with the TWGS each time.

--Devin gl...@manning.cs.ualberta.ca

David....@bbs.actrix.gen.nz

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Nov 1, 1992, 8:37:20 AM11/1/92

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In article <BwyIw...@news.cso.uiuc.edu> mjk3...@uxa.cso.uiuc.edu (the Weasel...) writes:
>
> One feature of the TWGS that I envy is the built in CDA. I wish my Zip
> could be accesed like the TWGS anytime I wanted to. I hate booting GS/OS
> or even running Zippy to just change the speed.

I don't have that problem. I just memorized the code needed to turn
the ZIP on or off. :-)

OFF:

lda #$55
sta $c05a
sta $c05a
sta $c05a
sta $c05a
stz $c05a
asl
sta $c05a
rts

To turn it on again, change the 'stz $c05a' to 'stz $c05b'.

I can type this into the mini-assembler faster than I can boot ProDOS-8
and locate ZIPPY. :-)
--
David Empson

Internet: David....@bbs.actrix.gen.nz EMPS...@kosmos.wcc.govt.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand

Andrew Roughan

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Nov 1, 1992, 8:26:18 AM11/1/92

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gl...@cs.UAlberta.CA (Reade Glyn Devin) writes:
> [...] I _have_ had
>problems with TWGS. [...]

>I'm using ROM 01, AEDL 2400, iS FPE, Zip 9/32, Ramkeeper w/ GSRam+ 3Meg
>and apple 1Meg.

This may or may not have been related, but the FPE is _not_ compatible with
the TWGS.

Regards,
Andrew.
--
Andrew Roughan | Snail: PO Box 65 Wahroonga, NSW 2076 Australia
Apple // Sub-editor | Net: po...@socs.uts.edu.au
"Applecations" magazine | Ask me how "Eclipse" is going... (BBS software)
Apple Users' Group, Sydney | There can never be enough Apple //s

ONG TAT-WEE

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Nov 1, 1992, 11:57:52 AM11/1/92

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Let me give my $0.02 worth of Zips:

I recently upgraded my 8/16 Zip personally with my friend's help. As we
live in Singapore, the gigantic cost of postal required to send the card
back to Zip Technologies made us took the risk of violating the
warranty. During the upgrading process, one of the capacitors on board
was accidentally damaged. It was crushed to pieces. As the capacitance
was not written on it, we couldn't find a replacement.

But we carried on with the upgrade and finally got my Zip working at 9
mhz with 32k cache. The crushed capacitor is still missing. The fact
that the card survived the damage gives me even more confidence in it
and the upgrade costs us only S$50.00 (or US$25.00) for everything. It
couldn't go to 64k cache 'coz the crushed capacitor happens to be for
the other pair of cache ram chips. Does anyone know what's the
capacitance of the thing?

The only problem I have now is that I can't do a disk-to-disk copy from
the System 6.0 Finder with the Zip on. Finder reads the source disk
until the last group of blocks and gives an error message that the disk
was ejected accidentally during the operation when it was in face in the
drive all the time! I either have to disable the Zip (which I don't
bother) or use Photonix (which I do). I suspect this problem could be
due to pushing the Zip from 8 to 9 mhz as mine is the old version 1.01.

- DOTW -

Gregory Ross Thompson

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Nov 1, 1992, 4:58:00 AM11/1/92

to

jo...@well.sf.ca.us (Joe Kohn) writes:
> To: Greg Thompson
> Re: Zip vs TWGS
>
> You hold on, Greg. You even quoted me. I said 70% of the people at the
> Gravenstein Apple IIGS User Group that purchased Zips had to return them as
> they didn't work.

Argh. I didn't mean that as a flame, I'm sorry if it came out that
way.

> Subtracting 70% from 100% gives you 30%. So, 30% of the people that
> purchased Zips in my user group got ones that worked right out of the box.
>
> That is a fact. And, you can't argue with facts.

Fine. I was just trying to make a statement on the other side of
yours. Your post was saying that the zip was bad. Mine was saying
that it was good. Again, I didn't mean it as a flame, and I hope you
don't take it as one.

Still, the fact that I've got one which works fine, Todd's got one
that works fine, Brendan has one that works fine, etc... Tons of
people have 'em. Some are even screaming at amazingly high speeds.
They are good boards, and for me, and a whole lot of other people,
they do the job.

Glynne Tolar

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Oct 31, 1992, 1:29:49 PM10/31/92

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In article <BwyIw...@news.cso.uiuc.edu> mjk3...@uxa.cso.uiuc.edu (the Weasel...) writes:

>I believe that most of the problems concerning the ZipGS was with the faster
>boards like the 9mhz and faster... Personally, I've heard almost nothing
>about the 7 or 8mhz boards. I have a 8mhz for a year and a half with no
>problems. =)

I have to agree with that statement, almost. To make higher speed Zips, Zip
pushes 65816s beyound their rated limit. I don't think Zip tests their
product long enough before it goes out the door.

Let me tell you a story about my expirence with Zip. I originally bought
a 9MHz/16k Zip over a year ago. I had problems with it on occation with it
crashing. I seem to fix the problem by running it on a 250w power supply
and leaving the lid off. I can't sware which did the trick, but everything
ran smoother afterwords. During this time I got daring and modified my Zip
for a socket for the TTL oscilator, split cache mod, and a replacement of a
cap. on the board to fix a video problem with the PC TRansporter (only needed
on SOME PCTs.

A year or so later while I was removing a card (yes, with the power off) my
Zip started acting flakey and then died. My RamFAST card also died. Please
note I have no idea what caused all the damage. OK, so after checking to see
if I could fix these cards I call Zip about the ZipGSX. I was honest with
them and told them I had a 9/16 that I modified. They said I'd have to buy a
new one then but would give me a $30 discount if I sent the old card back.
Thinking about it only after I agreed to do it. I think I had $30 in spare
parts on the board, but I sent it back anyway. I did tell them I did upgrade
it to a 64k cache myself but would send it back as originally configured.

A few days later I receive a package in the mail from Zip. NEW CARD! GREAT!
Some interesting things about this card. 1) When I first saw it I noticed
that it did not have the +5.7v regulator on it and the CPU was marked for
10MHz. and 2) When I installed it and RAM Zippy and reported I had a 9/64.
INTERESTING, I said. I looke at the box and the invoice and both said I
got a 9/16. Sigh! OK I decided to leave well enough alone. The card works
GREAT! It has NOT given me one problem. Unlike my old one. Note the old
one had a 7MHz CPU pushed to 9. This makes me believe that must Zips with
problems may be because they are pushed too far!

I thought I Zip problems were over and then yesterday I got another package
in the mail. It was another 9/16. Looking at the invoice it said they
repaired it at no charge. STRANGE. This unit was more like mine (7 pushed
to 9). I tried it out and it ran fine for a little while then it started
crashing. Hmmmmm? Now I have one well working Zip and another somewhat
working Zip. I suspect if I put a better CPU in the somewhat working unit
It will run fine. Now, where do I get one?

Thought you all might find this story interesting. I still like my Zip and
RamFAST (now in Drews hands for repair). I can't begin to tell you what
a difference there is between a GS with a Zip and RamFAST and one with only
a Apple DMA SCSI card. I'm so glad I had it as a backup though!

>
>---Mike

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Nov 2, 1992, 1:05:29 PM11/2/92

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po...@socs.uts.edu.au (Andrew Roughan) writes:

>This may or may not have been related, but the FPE is _not_ compatible with
>the TWGS.

Sorry, but I'm going to disagree with you. I've been running an FPE and
a TWGS since TWGS came out and it's fine.

Scott Gentry
Intergraph Corporation
sc...@brnded.reston.ingr.com
or... afls...@aol.com
--
*******************************************************************************
* W. Scott Gentry | America Online: AFL Scott | No! Not me! *
* Intergraph Corporation | uunet: uunet!ingr!ne1300!brnded!scott|I'm innocent!*
*******************************************************************************

Paul Benson

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Nov 2, 1992, 3:42:20 PM11/2/92

to

In <1992Nov2.1...@b8.b8.ingr.com> Scott Gentry writes:

>po...@socs.uts.edu.au (Andrew Roughan) writes:
>>the FPE is _not_ compatible with the TWGS.
>
>Sorry, but I'm going to disagree with you. I've been running an FPE and
>a TWGS since TWGS came out and it's fine.

It depends how old your FPE is. I only noticed mine was 'bad' when I used
some of the FPE intensive graphing functions (demos) in Prosel-16's
calculator. I was told that I needed to get my FPE updated; unfortunately,
IS does not return my calls, so I've been unable to get the update :(.

Pauley
GEnie: P.Benson1

ONG TAT-WEE

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Nov 2, 1992, 9:13:28 PM11/2/92

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David....@bbs.actrix.gen.nz wrote:
: In article <1992Nov1.1...@nuscc.nus.sg> isc1...@nusunix1.nus.sg (ONG TAT-WEE) writes:
:
: For all peculiar problems with ZIPs and 3.5" drives, I recommend

: making sure that slot 6 is set to 'slow' speed on the ZIP. (Slot 6
: contains the I/O locations used to access the 3.5" drive, even though
: the drive appears to be in slot 5.)
:
: I was having occasional strange problems, such as the drive going into
: an infinite seek back-and-forth loop, until I slowed down slot 6. I
: believe the problems were caused by tight CPU timing loops in the
: AppleDisk3.5 driver, which on rare occasions were causing a seek error.
: (The drive didn't quite seek far enough, so the driver recalibrated it
: and tried to seek again. This also failed, and it never stopped trying.)
: --

Thanks for the tip! I currently have my slot 6 running at Fast.
Think I'll slow it down to see if it solves the drive problem.

: David Empson

:
: Internet: David....@bbs.actrix.gen.nz EMPS...@kosmos.wcc.govt.nz
: Snail mail: P.O. Box 27-103, Wellington, New Zealand

- DOTW -

Reade Glyn Devin

unread,

Nov 2, 1992, 8:50:29 PM11/2/92

to

In article <1992Nov2.1...@b8.b8.ingr.com>, sc...@b8.b8.ingr.com (Scott Gentry) writes:
> po...@socs.uts.edu.au (Andrew Roughan) writes:
>
> >This may or may not have been related, but the FPE is _not_ compatible with
> >the TWGS.
>
> Sorry, but I'm going to disagree with you. I've been running an FPE and
> a TWGS since TWGS came out and it's fine.

It wouldn't have been related: I follow the practice of, when
having problems with a board, going to the bare stock config and
building it up from there. The TWGS still wouldn't work :)

--Devin gl...@manning.cs.ualberta.ca

ONG TAT-WEE

unread,

Nov 2, 1992, 9:10:34 PM11/2/92

to

Todd P. Whitesel (tod...@cco.caltech.edu) wrote:
: isc1...@nusunix1.nus.sg (ONG TAT-WEE) writes:
:
: This believe is something specific to the system 6 finder also. I am not sure

: but I never had that happen under system 5, with the same hardware setup. When
: I got system 6, I started noticing it.
:
: Todd Whitesel
: toddpw @ cco.caltech.edu

You're right! My System 5.0.4 Finder does 3.5" disk-to-disk
copy perfectly with my half-crippled Zip! I can never seem to get the
System 6.0 Finder to work though.
Another addition to the System 6.0 Finder bug list?

- DOTW -

Bill Logsdon

unread,

Nov 3, 1992, 3:20:57 AM11/3/92

to

One more thing (from my perspective) I have owned a 6.75 TWGS, a 10 and
also a 7 Zip.... and have had far LESS compatability problems with the
Transwarps, versus the Zip.... however, the Zip folks were VERY much more
helpful, versus AE.....

I presently am using the 10 mhz TW, and am very happy with it, but I must
say AE's hardware/apple user support is the pits... so, all things
considered, for a user that is unfamiliar with debugging problems, spend
the bucks for the Zip.... and get the fastest speed version you can afford
as your first purchase (to save on upgrade costs)..... you will be MUCH mor
happier with their customer support...

Todd P. Whitesel

unread,

Nov 4, 1992, 5:59:00 AM11/4/92

to

gto...@xcluud.sccsi.com (Glynne Tolar) writes:

>I think I now know why. Zip is testing a new 4 layer board that will reduce
>noise on ROM 01 machines. If you buy a Zip >12 MHz I am told that is what
>you will get. They tell me the ROM 01s are just too noisey.

What a relief. It's good to hear that they are finally doing what the rest of
the industry has done for years -- go 4 layer and devote two to +5 and ground
planes. The two power planes act like a large capacitor, and really augment the
standard debouncing caps you're used to seeing next to every chip. (The ROM 03
is a two-layer design, but its layout is a masterpiece of noise isolation.)

unread,

Nov 9, 1992, 12:59:34 PM11/9/92

to

In article <1992Nov5.0...@ausom.oz.au> cjs%auso...@sol.cc.deakin.oz.au writes:

>It is interesting that ZIP don't sell >9 MHZ zips out of Amarica .. I cann't
>figure this out .. why wouldn't they ship fast zips internationally??!!

Because chances are that the higher clock speeds don't conform to the more
rigid RF specifications used in Europe and Japan. The FCC standards tend
to be slightly more lenient than some of those others in certain areas. But
I would be interested to see a GS tested for class B with a Zip running at
about 15 MHz or so.. The fact that the low power Zips and RamFASTs flake
out sometimes could very well be due to them failing class A certification
which only specifies susceptability requirements. Since they're only selling
components and not the final computer, I'm not sure how the FCC regs work on
that point. I do know that any computer system used in the home that fails
class B can get you fined $1000/day of use (after detection) and/or system
confiscation. And companies that MAKE computers that fail class B can get
entire shipments confiscated!

>
>--
>Cameron Silver
>
>Auto reply does not work (sorry...). Reply to internet address:
>-->cjs%auso...@sol.cc.deakin.oz.au :-)

Todd P. Whitesel

unread,

Nov 10, 1992, 4:55:59 AM11/10/92

to

foeg...@ccwf.cc.utexas.edu (Michael Foegelle) writes:

>I would be interested to see a GS tested for class B with a Zip running at
>about 15 MHz or so.. The fact that the low power Zips and RamFASTs flake
>out sometimes could very well be due to them failing class A certification

The GS case is one large faraday cage, so I'm not sure how much this really
matters. In the case of the Zip there is very strong evidence that the original
two-layer board design simply could not filter out noise in the power rails --
which low power CMOS is very sensitive to. My best info on the RAMfast so far
is that the low power drivers simply can't compete with noise on the data bus
generated by some peripherals and by the //e motherboard.

Your point about 15 mhz is a good one, though; I wouldn't be surprised if the
old Zip design simply doesn't run once you get much higher than that. Hopefully
the new four-layer board will be sufficiently quiet. Drew says his RAMfast D
board has Zero noise on the power rails, it's the busses to the rest of the
system that are the problem.

Michael Foegelle

unread,

Nov 13, 1992, 6:58:38 PM11/13/92

to

In article <1do0vf...@gap.caltech.edu> tod...@cco.caltech.edu (Todd P. Whitesel) writes:
>foeg...@ccwf.cc.utexas.edu (Michael Foegelle) writes:
>
>>I would be interested to see a GS tested for class B with a Zip running at
>>about 15 MHz or so.. The fact that the low power Zips and RamFASTs flake
>>out sometimes could very well be due to them failing class A certification
>
>The GS case is one large faraday cage, so I'm not sure how much this really
>matters. In the case of the Zip there is very strong evidence that the original
>two-layer board design simply could not filter out noise in the power rails --
>which low power CMOS is very sensitive to. My best info on the RAMfast so far
>is that the low power drivers simply can't compete with noise on the data bus
>generated by some peripherals and by the //e motherboard.

Well, we've already held our discussion in E-mail on most of this, but just
in case anyone else is interested, I'll re-iterate a few of the finer points.

As soon as you poke a hole in a case, whether to hang a cable out, or for
ventilation, or whatever, you no longer have a faraday cage. And with a
cable, you've got one whopping big antenna instead! (Power cords, printer
cables, modem cables, monitor cables, joystick port, etc.) Sheilded or not,
these things can radiate if there are alternate ground paths available. And
then there's MAGNETIC fields, which a simple conductive shielding doesn't
handle.

There's also the consideration of these low power cards being susceptible to
external fields produced by the card next to them, etc. Even though there
may be no problem OUTSIDE the case, when you've got a card with wires running
every which way past another that is an inch away and might not be too clean,
(noise-wise) you're likely to run into trouble.

>
>Your point about 15 mhz is a good one, though; I wouldn't be surprised if the
>old Zip design simply doesn't run once you get much higher than that. Hopefully
>the new four-layer board will be sufficiently quiet. Drew says his RAMfast D
>board has Zero noise on the power rails, it's the busses to the rest of the
>system that are the problem.
>
>Todd Whitesel
>toddpw @ cco.caltech.edu

Anyways, I think that covers most of the points we tossed back and forth well
enough for anyone else's edification...

Michael Foegelle