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Drums vs Head-Per-Track Disks
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Quadibloc
Apr 24, 2013, 3:22:12 PM4/24/13
to
The original paper on TSS/8 says that the prototype system was
developed to use either a disk (presumably one of the head-per-track
ones that DEC had at the time) or a drum as its swap device. But IIRC,
I read that TSS/8 as delivered could only be used with one of the two
head-per-track disks made by DEC, and not with the model 251 drum.
OS/8 could work with a wide variety of mass-storage devices, even the
humble DECtape, but also not with the drum. Although it may have
required hardware options not available for the original PDP-8, for
which that drum was made.
On the topic of hardware requirements, I've read that OS/8 FORTRAN
required an FPP-12. According to the manuals, nothing is said about
FORTRAN II, except that it's improved from 8K FORTRAN. FORTRAN IV can
use an FPP-12 if available, they say, but it is required if you want
to use double precision (and then an FPP-12A with the extended
precision option is required).
Complex numbers, even though they involve only single-precision
calculations, also require a double-precision FPP; I guess that's for
fast loads and stores.
But then, the manual could be wrong. I know the original PDP-8/e Small
Computer Handbook got its EAE all wrong.
John Savard
developed to use either a disk (presumably one of the head-per-track
ones that DEC had at the time) or a drum as its swap device. But IIRC,
I read that TSS/8 as delivered could only be used with one of the two
head-per-track disks made by DEC, and not with the model 251 drum.
OS/8 could work with a wide variety of mass-storage devices, even the
humble DECtape, but also not with the drum. Although it may have
required hardware options not available for the original PDP-8, for
which that drum was made.
On the topic of hardware requirements, I've read that OS/8 FORTRAN
required an FPP-12. According to the manuals, nothing is said about
FORTRAN II, except that it's improved from 8K FORTRAN. FORTRAN IV can
use an FPP-12 if available, they say, but it is required if you want
to use double precision (and then an FPP-12A with the extended
precision option is required).
Complex numbers, even though they involve only single-precision
calculations, also require a double-precision FPP; I guess that's for
fast loads and stores.
But then, the manual could be wrong. I know the original PDP-8/e Small
Computer Handbook got its EAE all wrong.
John Savard
Quadibloc
Apr 24, 2013, 10:29:15 PM4/24/13
to
I see part of my answer: the KT/8I option that gave the 8/I a
privileged mode required the 8/I backplane - and the drums were only
offered as peripherals for the PDP-8, not later models.
John Savard
privileged mode required the 8/I backplane - and the drums were only
offered as peripherals for the PDP-8, not later models.
John Savard
Rob Doyle
Apr 24, 2013, 10:41:32 PM4/24/13
to
On 4/24/2013 12:22 PM, Quadibloc wrote:
> But then, the manual could be wrong. I know the original PDP-8/e Small
> Computer Handbook got its EAE all wrong.
I don't know about that but they must have eventually got it correct.
> But then, the manual could be wrong. I know the original PDP-8/e Small
> Computer Handbook got its EAE all wrong.
The version of the Handbook that I have was good enough to implement EAE
in my PDP-8 FPGA and have it pass the diagnostics.
Rob.
David Gesswein
Apr 26, 2013, 9:24:01 AM4/26/13
to
In article <f7e5508d-8b96-457f...@l5g2000pbp.googlegroups.com>,
FORTRAN IV. The OS/8 FORTRAN IV does require FPP for double.
Quadibloc <jsa...@ecn.ab.ca> wrote:
>
>On the topic of hardware requirements, I've read that OS/8 FORTRAN
>required an FPP-12. According to the manuals, nothing is said about
>FORTRAN II, except that it's improved from 8K FORTRAN. FORTRAN IV can
>use an FPP-12 if available, they say, but it is required if you want
>to use double precision (and then an FPP-12A with the extended
>precision option is required).
>
What is OS/8 FORTRAN? The FORTRAN I am familiar with under OS/8 is the
>
>On the topic of hardware requirements, I've read that OS/8 FORTRAN
>required an FPP-12. According to the manuals, nothing is said about
>FORTRAN II, except that it's improved from 8K FORTRAN. FORTRAN IV can
>use an FPP-12 if available, they say, but it is required if you want
>to use double precision (and then an FPP-12A with the extended
>precision option is required).
>
FORTRAN IV. The OS/8 FORTRAN IV does require FPP for double.
David Gesswein
Apr 26, 2013, 9:29:38 AM4/26/13
to
In article <9bf8de67-8f1e-470f...@j20g2000yqo.googlegroups.com>,
From what I understand and have seen so far with my equipment is the negative
bus on the 8/I was compatible with the original 8 so the drum should work.
I suspect it was just discontinued quickly and rare so wasn't supported.
I haven't heard of a drum existing or even a system that had one.
bus on the 8/I was compatible with the original 8 so the drum should work.
I suspect it was just discontinued quickly and rare so wasn't supported.
I haven't heard of a drum existing or even a system that had one.
Quadibloc
Apr 26, 2013, 10:02:17 AM4/26/13
to
On Apr 26, 7:24 am, d...@www.pdp8online.com (David Gesswein) wrote:
> What is OS/8 FORTRAN? The FORTRAN I am familiar with under OS/8 is the
> FORTRAN IV. The OS/8 FORTRAN IV does require FPP for double.
Yes, it requires it for double - and, strangely enough, for complex as
> What is OS/8 FORTRAN? The FORTRAN I am familiar with under OS/8 is the
> FORTRAN IV. The OS/8 FORTRAN IV does require FPP for double.
well. But not to run at all, as some sources have said.
But there's also a FORTRAN II for OS/8, and that one, unlike FORTRAN
IV, might even have been standard with the operating system, I had
thought.
John Savard
Rich Alderson
Apr 26, 2013, 2:39:54 PM4/26/13
to
Quadibloc <jsa...@ecn.ab.ca> writes:
Both are documented in th OS/8 Handbook, FORTRAN II in chapter 7 and FORTRAN IV
in chapter 8. F2 uses the SABR assembler (chapter 4), while F4 uses RALF (also
in chapter 8).
--
Rich Alderson ne...@alderson.users.panix.com
the russet leaves of an autumn oak/inspire once again the failed poet/
to take up his pen/and essay to place his meagre words upon the page...
in chapter 8. F2 uses the SABR assembler (chapter 4), while F4 uses RALF (also
in chapter 8).
--
Rich Alderson ne...@alderson.users.panix.com
the russet leaves of an autumn oak/inspire once again the failed poet/
to take up his pen/and essay to place his meagre words upon the page...
Robert Adamson <rwadamsonhotmail<dot>com>
Apr 26, 2013, 6:10:58 PM4/26/13
to
On 26 Apr 2013 14:39:54 -0400, Rich Alderson
is covered in the OS/8 documentation. It's an extension of the
paper-tape F2 system. The Fortran IV system was an extra-cost option
and although it's mentioned in the basic OS/8 documentation it also
had its own (much more complete) documentation which is really
necessary to get the most out of it.
<ne...@alderson.users.panix.com> wrote:
>Quadibloc <jsa...@ecn.ab.ca> writes:
>
>> On Apr 26, 7:24=A0am, d...@www.pdp8online.com (David Gesswein) wrote:
>
>>> What is OS/8 FORTRAN? The FORTRAN I am familiar with under OS/8 is the
>>> FORTRAN IV. The OS/8 FORTRAN IV does require FPP for double.
>
>> Yes, it requires it for double - and, strangely enough, for complex as
>> well. But not to run at all, as some sources have said.
>
>> But there's also a FORTRAN II for OS/8, and that one, unlike FORTRAN
>> IV, might even have been standard with the operating system, I had
>> thought.
>
>Both are documented in th OS/8 Handbook, FORTRAN II in chapter 7 and FORTRAN IV
>in chapter 8. F2 uses the SABR assembler (chapter 4), while F4 uses RALF (also
>in chapter 8).
The Fortran II system was supplied with the OS/8 operating system and
>Quadibloc <jsa...@ecn.ab.ca> writes:
>
>> On Apr 26, 7:24=A0am, d...@www.pdp8online.com (David Gesswein) wrote:
>
>>> What is OS/8 FORTRAN? The FORTRAN I am familiar with under OS/8 is the
>>> FORTRAN IV. The OS/8 FORTRAN IV does require FPP for double.
>
>> Yes, it requires it for double - and, strangely enough, for complex as
>> well. But not to run at all, as some sources have said.
>
>> But there's also a FORTRAN II for OS/8, and that one, unlike FORTRAN
>> IV, might even have been standard with the operating system, I had
>> thought.
>
>Both are documented in th OS/8 Handbook, FORTRAN II in chapter 7 and FORTRAN IV
>in chapter 8. F2 uses the SABR assembler (chapter 4), while F4 uses RALF (also
>in chapter 8).
is covered in the OS/8 documentation. It's an extension of the
paper-tape F2 system. The Fortran IV system was an extra-cost option
and although it's mentioned in the basic OS/8 documentation it also
had its own (much more complete) documentation which is really
necessary to get the most out of it.
Quadibloc
Apr 28, 2013, 3:51:39 AM4/28/13
to
On Apr 24, 8:41 pm, Rob Doyle <radioe...@gmail.com> wrote:
> The version of the Handbook that I have was good enough to implement EAE
> in my PDP-8 FPGA and have it pass the diagnostics.
Oh, yes. The handbooks were generally very accurate. But there was a
> The version of the Handbook that I have was good enough to implement EAE
> in my PDP-8 FPGA and have it pass the diagnostics.
1972 edition - not on Bitsavers - of the Small Computer Handbook that
described the PDP-8/e EAE based on a preliminary spec.
John Savard
Quadibloc
May 6, 2013, 6:10:29 PM5/6/13
to
https://www.grc.com/pdp-8/os8-sbc.htm
which lists manuals has that one at the head of the list, I think.
Since he left out the cover, I can't be sure without actually
comparing the EAE description..
John Savard
Quadibloc
May 7, 2013, 8:28:07 PM5/7/13
to
On May 6, 4:10 pm, Quadibloc <jsav...@ecn.ab.ca> wrote:
> I think I may have found it on the web, though:
>
> https://www.grc.com/pdp-8/os8-sbc.htm
No, the manual at this link contains the correct description of the 8/
> I think I may have found it on the web, though:
>
> https://www.grc.com/pdp-8/os8-sbc.htm
e EAE. It was an earlier manual that had the differences - and I now
see they were small ones.
John Savard
Quadibloc
May 8, 2013, 6:00:38 PM5/8/13
to
On May 7, 6:28 pm, Quadibloc <jsav...@ecn.ab.ca> wrote:
> It was an earlier manual that had the differences - and I now
> see they were small ones.
Maybe not so small. In my searches on the web for more information, I
> It was an earlier manual that had the differences - and I now
> see they were small ones.
found a web site (or a FAQ posting) asserting that the preliminary
description of the EAE deliberately included useless instructions -
NMU was one of them - so as to mislead engineers at DCC who were
making an imitation of the PDP-8.
Ah, it was a posting on this very newsgroup:
https://groups.google.com/forum/#!msg/alt.sys.pdp8/wiB-ZtkitQI/EEeMA_3llJMJ
John Savard
Quadibloc
May 8, 2013, 6:03:38 PM5/8/13
to
On May 8, 4:00 pm, Quadibloc <jsav...@ecn.ab.ca> wrote:
> Ah, it was a posting on this very newsgroup:
Here's a better link to the same post:
> Ah, it was a posting on this very newsgroup:
<https://groups.google.com/group/alt.sys.pdp8/browse_frm/thread/
c2207e66d922b502/9394e5fd038c4710?hl=en&lnk=gst&q=stuff+that+never
+quite+happened#9394e5fd038c4710>
John Savard
Quadibloc
May 8, 2013, 6:05:06 PM5/8/13
to
Oh, and here's part 2 of that post, in case you're curious:
<https://groups.google.com/group/alt.sys.pdp8/browse_frm/thread/
2f87117bbe086564/396fb86deae13b9b?hl=en&lnk=gst&q=stuff+that+never
+quite+happened#396fb86deae13b9b>
John Savard
<https://groups.google.com/group/alt.sys.pdp8/browse_frm/thread/
2f87117bbe086564/396fb86deae13b9b?hl=en&lnk=gst&q=stuff+that+never
+quite+happened#396fb86deae13b9b>
John Savard
Quadibloc
May 9, 2013, 1:06:35 PM5/9/13
to
The angle brackets are supposed to make things better, but apparently
at least in some newsreaders, they don't.
So here we are again:
https://groups.google.com/group/alt.sys.pdp8/browse_frm/thread/c2207e66d922b502/9394e5fd038c4710?hl=en&lnk=gst&q=stuff+that+never+quite+happened#9394e5fd038c4710
https://groups.google.com/group/alt.sys.pdp8/browse_frm/thread/2f87117bbe086564/396fb86deae13b9b?hl=en&lnk=gst&q=stuff+that+never+quite+happened#396fb86deae13b9b
John Savard
at least in some newsreaders, they don't.
So here we are again:
https://groups.google.com/group/alt.sys.pdp8/browse_frm/thread/c2207e66d922b502/9394e5fd038c4710?hl=en&lnk=gst&q=stuff+that+never+quite+happened#9394e5fd038c4710
https://groups.google.com/group/alt.sys.pdp8/browse_frm/thread/2f87117bbe086564/396fb86deae13b9b?hl=en&lnk=gst&q=stuff+that+never+quite+happened#396fb86deae13b9b
John Savard
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