Hey gang, a few months ago I had found the 1968/1969 document spec of
RS-232. But now, I'm unable to find it again !
At Internet Archive, there is one link/reference to it, but it appears to
just be the cover page (which does have the date of August 1969).
I see the EIA RS-232-C spec dated from 1991 (but I think that date is just
marking when EIA took over stewardship of the standard, but the spec should
reflect/match the original 1969 one).
In the manual for the DataSet 103C (from a few years earlier than 1969), it
outlines signal lines all labeled like RS-232. But I wouldn't call it an
RS-232 spec.
Like most standards, it takes a number of years for a community/critical
mass of products to understand it and adopt it correctly. Even ASCII
wasn't globally recognized and adopted until maybe 15 years after it was
introduced? So I was trying to track down the "earliest mention" of
RS-232, to pinpoint it really being from 1962.
Technically it appears the EIA "guards" that spec, and makes it expensive
to officially download it. Maybe they took an initiative to try to scrub
earlier editions from the public web, maybe that's why it's harder to find
now? But I was pretty sure I found a scanned copy of it at some point (the
Aug 1969 one).
If anyone happens to have a printer version (of a 1969 or earlier RS-232
spec) - it would at least be nice to know that exists somewhere. I'm
pretty sure that "original spec" called out +/- 3 to 25V, later ones maybe
used 20V or 15V.
-Steve
I have been talking with Paul Anderson about some PDP-11/05 parts.
End of January Paul wrote about medical problems and possible surgery.
I have not been able to get in touch with him since and hope he is OK.
Has anyone here heard anything about Paul since January?
Thanks
Tom
Does anyone know anything about the key lock on the mains on/off
switch of the P3800?
I have one without a key. I can't identify the lock manufacturer (no
markings on it at all) so I've not been able to get a blank to cut a
replacement key. A friend who is a locksmith said she'd never seen
anything like it.
Any ideas who made the lock itself?
Were all P3800 machines normally 'keyed alike' If so, a copy of an
existing key (anyone have one?) would be a great help.
Yes, I can trvially bypass the lock/switch mechanically or
electrically. But I want to try to get this thing as original as
possible.
-tony
I have posted my PDP8 and PDP12 paper tape images onto my Google Drive
(where they are also available to CHM/Al Kossow for their "bits" collection.
https://drive.google.com/open?id=0B2v4WRwISEQRWWFFdVpCZWFTZEU&resourcekey=0…
Look in bits/DEC/pdp8 and bits/DEC/pdp12 for folders "From_JayJaeger".
There is a PDF of the contents of BOTH directories in each one (it is
the same PDF in each case).
JRJ
FWIW, both Grok and ChatGPT say the same thing.
The RS-232 standard was first described in 1960 by the Electronic Industries Association (EIA). Its full original designation was EIA RS-232, where “RS” stands for Recommended Standard.
Many years ago (March 2007 to be precise), I posted to this mailing list because I had typed in (by hand) the octal listing of TBX (Tiny BASIC Extended) from Dr Dobbs Vol. 1 No. 1, pp 16-17(
It turns out that this 8080 code basically worked and I was able to verify it in a Z-80 simulator.
Fast forward to 2025, and I have rediscovered this code and posted it to GitHub. I have also included an 8080 emulator in JavaScript so you can run TBX in your browser:
https://github.com/ericscharff/tinybasic
While keying in two pages of octal listings was an interesting exercise, I’m less keen to type in the source code for TBX, which appeared in Vol 1 No 2, pp 13-31.
I’d like to preserve this source code alongside the octal dump in my github repository.
Does anyone happen to have a listing of this source code in ASCII, or perhaps access to high quality OCR software that could perhaps automate the job?
The closest I can find is on Whipple’s own web site athttps://whippleway.com/Source_Code/TBX.asm
Which seems quite close, but is missing things from the first TBX (e.g., FOR / NXT loops)
Many thanks,
-Eric
Way back when, I asked on the list about null modems for the DEC Pro which I
planned to use for experiments with SLIP. PRO/VENIX doesn't have any network
capability other than UUCP, and it doesn't seem like anything else supports the
Ethernet CTI card other than P/OS (of course) and the unofficial 2.9BSD, but I
like PRO/VENIX V2.0 better because it's a real System V.
Anyway, here's a simple implementation with four clients (ping, DNS, NTP and
command-reply TCP) which runs over the printer port at the standard 4800bps.
That keeps the main serial port free as a second terminal and for Kermit.
Getting it to work with both the PRO/VENIX Rev. 2.0 and V2.0 compilers (i.e.,
older-than-V7 and System V respectively) was interesting.
Unfortunately Xhomer's serial port emulation isn't good enough for this yet;
many dropped bytes. It works fine with my real DEC Pro 380.
https://oldvcr.blogspot.com/2025/04/lets-give-provenix-barely-adequate-pre.…https://github.com/classilla/bass
--
------------------------------------ personal: http://www.cameronkaiser.com/ --
Cameron Kaiser * Floodgap Systems * www.floodgap.com * ckaiser(a)floodgap.com
-- God made the integers; all else is the work of Man. -- Kronecker -----------
