On 2013-01-06 21:47, John Wilson wrote:
I still can't find where it says "8085A" in the 110/130 manual, but page
B-3 gives I/O page timings and mentions an "I/O microprocessor" and the
fact that word I/O takes 90 usec but byte I/O takes 180 usec. So that
certainly explains the difference in the DUV driver. Plus the manual
specifically says that RSX11S is available for the /110, so I guess it
was even supported! Sweet.
Also mentioned on page 4-6, but pretty much with the same level of detail. Byte writes cause a read-modify-write. Time of 180 usec. And there is an (unmentioned) 8-bit microprocessor acting in between the PDP-11 and any peripherials.
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
I still can't find where it says "8085A" in the 110/130 manual, but page
B-3 gives I/O page timings and mentions an "I/O microprocessor" and the
fact that word I/O takes 90 usec but byte I/O takes 180 usec. So that
certainly explains the difference in the DUV driver. Plus the manual
specifically says that RSX11S is available for the /110, so I guess it
was even supported! Sweet.
John Wilson
D Bit
On 2013-01-06 21:34, John Wilson wrote:
From: "Steve Davidson" <jeep at scshome.net>
The main target for the PDT-11 was RT-11. It was slow. The floppies
spent a great deal of time seeking.
Slow, but still a PDP-11! I had a /150 (plus VT62 and LA36) as my main
computer when I was a frosh at RPI ('84-'85) and it was quite a bit above
average compared to other personal computers at the time (C64, Apple ][,
TRS-80, Atari 800, but IBM PCs were still rare -- so mostly fun toys with
pretty graphics but slow and no disk space and usually no 80-column text).
With 60 KB and most of the floppy/TU58 driver up in ROM space its free
memory was at the very high end of MMU-less PDP-11s -- stuff fits in a PDT
that won't run on a "real" LSI-11.
I ran a PDP-8 at home back then. Boy, those RK05 were fast, and stored a lot. :-)
Also, PAL8 was ridiculously fast... MACREL was a bit worse... But still, compared to what most people played with...
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
On 2013-01-06 21:28, John Wilson wrote:
From: Johnny Billquist <bqt at softjar.se>
You must be talking of the PDT-11/150 then. The /110 and /130 sat inside
a VT100 shell. Extremely similar to a VT103 (I actually never figured
out what the difference between a VT103 and a PDT-11/130 is.)
I may be grossly misinformed, but my understanding is that although the
/110 and /130 both live inside a VT100, they're *not* like VT103s, and
have no Q-bus but use a custom CPU board just like the /150 (I doubt it's
the exact same board, but a similar design).
I could have sworn the 110/130 manual on bitsavers (which is misfiled
away from the 150 manual -- I forget where) said so but on a quick skim I
can't find it. The I/O hardware has enough programming differences that
it can't be regular Q-bus stuff, although I suppose they could have made
a whole set of PDT-specific boards.
You know, I had never even thought that thought, but now that you mention it, it makes total sense. I think you must be right.
All the PDT-11 use the same system board. It's not a Qbus at all, in any of them.
That definitely also makes it very different from the VT103.
Thanks for making me understand this. :-)
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
From: <Paul_Koning at Dell.com>
BTW, does anyone know why SIMH doesn't support booting from RC11?
I never miss a chance for a plug: Ersatz-11 has RC11 booting.
(The device name is DC:, so MOUNT/DISMOUNT/BOOT work as usual.)
John Wilson
D Bit
From: "Steve Davidson" <jeep at scshome.net>
The main target for the PDT-11 was RT-11. It was slow. The floppies
spent a great deal of time seeking.
Slow, but still a PDP-11! I had a /150 (plus VT62 and LA36) as my main
computer when I was a frosh at RPI ('84-'85) and it was quite a bit above
average compared to other personal computers at the time (C64, Apple ][,
TRS-80, Atari 800, but IBM PCs were still rare -- so mostly fun toys with
pretty graphics but slow and no disk space and usually no 80-column text).
With 60 KB and most of the floppy/TU58 driver up in ROM space its free
memory was at the very high end of MMU-less PDP-11s -- stuff fits in a PDT
that won't run on a "real" LSI-11.
John Wilson
D Bit
From: Johnny Billquist <bqt at softjar.se>
You must be talking of the PDT-11/150 then. The /110 and /130 sat inside
a VT100 shell. Extremely similar to a VT103 (I actually never figured
out what the difference between a VT103 and a PDT-11/130 is.)
I may be grossly misinformed, but my understanding is that although the
/110 and /130 both live inside a VT100, they're *not* like VT103s, and
have no Q-bus but use a custom CPU board just like the /150 (I doubt it's
the exact same board, but a similar design).
I could have sworn the 110/130 manual on bitsavers (which is misfiled
away from the 150 manual -- I forget where) said so but on a quick skim I
can't find it. The I/O hardware has enough programming differences that
it can't be regular Q-bus stuff, although I suppose they could have made
a whole set of PDT-specific boards.
John Wilson
D Bit
On 2013-01-06 21:22, Paul_Koning at Dell.com wrote:
On Jan 6, 2013, at 2:50 PM, Johnny Billquist wrote:
...
I'm even more curious what a PDT-11 optimization is doing in an RSX
driver...was there at one time an RSX product product planned for the
PDT family?
I'm not at all surprised to learn that RSX ran on the PDT-11.
RSX can run on pretty much any PDP-11, as long as you have atleast around 50K of ram. That's about the lower limit, I'd guess. No other hardware frills or features required
RT requires far less. In college, I ported RT to run on the physics department 11/20, which had 8 kW of memory. It required a port because for a disk it had an RC11, which RT did not support. Fortunately, one of the RT authors had come to work at our college, and he helped me a lot. I asked him "why no RC11 support". Answer: "there weren't any around DEC to test it on".
Yes. RT-11 can run on even smaller things, but RSX can really run on much less than most people believe.
Originally that machine ran DOS-11 V4, ugh. RT was a much better OS. We ran RT Basic on it, with mods I made to support all the lab equipment (DR11-A, AD-01, AD-11, KW11-P). Interrupt handlers written in Basic, fun...
BTW, does anyone know why SIMH doesn't support booting from RC11?
Noone have written the code for it? :-)
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
On 2013-01-06 21:18, Johnny Billquist wrote:
I think only the 11/130 had the TU58. The /110, as John mentioned,
supported only downline loading of the system from somewhere else.
I know I've seen the manuals... Hmm, hang on...
Ah! Found it.
The PDT-11/150 documents sits under pdp-11 on bitsavers.
The PDT-11/110 and /130 sits under terminals on bitsavers. That's why I
didn't find it at first...
And of course, reading through manuals always gives answers...
Yes, it's RSX-11S that was supported on the PDT-11. Page 1-5 of the PDT-11/110 and /130 manual.
Hmm, reading through this a bit more, it would appear that the /110 was intended for RSX, while the /130 was intended for RT-11.
Makes sense, I guess, since you could have a pretty full RT-11 environment there, but for RSX, you'd need some other system for the development, and run the PDT-11/110 with no mass storage, and 11S downloaded at boot, running diskless.
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
On Jan 6, 2013, at 2:50 PM, Johnny Billquist wrote:
...
I'm even more curious what a PDT-11 optimization is doing in an RSX
driver...was there at one time an RSX product product planned for the
PDT family?
I'm not at all surprised to learn that RSX ran on the PDT-11.
RSX can run on pretty much any PDP-11, as long as you have atleast around 50K of ram. That's about the lower limit, I'd guess. No other hardware frills or features required
RT requires far less. In college, I ported RT to run on the physics department 11/20, which had 8 kW of memory. It required a port because for a disk it had an RC11, which RT did not support. Fortunately, one of the RT authors had come to work at our college, and he helped me a lot. I asked him "why no RC11 support". Answer: "there weren't any around DEC to test it on".
Originally that machine ran DOS-11 V4, ugh. RT was a much better OS. We ran RT Basic on it, with mods I made to support all the lab equipment (DR11-A, AD-01, AD-11, KW11-P). Interrupt handlers written in Basic, fun...
BTW, does anyone know why SIMH doesn't support booting from RC11?
paul
