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by Tom Hunter

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

2 months, 2 weeks

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RS232 Spec

by Steve Lewis

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

2 months, 2 weeks

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PDP-8 and PDP-12 Paper Tape Images Posted (Re: Paper Tape Reader Needed)

by Jay Jaeger

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

2 months, 2 weeks

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Re: RS232 Spec

by donald donaldwhittemore.com

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.

2 months, 2 weeks

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Looking for Tiny BASIC Extended source code

by Eric Scharff

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

2 months, 2 weeks

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SLIP TCP/IP stack for PRO/VENIX

by Cameron Kaiser

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 -----------

2 months, 2 weeks

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VCF East 2025 Survey Results

by Jeffrey Brace

VCF East 2025 Survey results: https://www.surveymonkey.com/stories/SM-chUD9AoxbzNkIk230AwghQ_3D_3D/ Jeff Brace VCF East Showrunner

2 months, 2 weeks

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System Source Swap Meet April 26 & 27, 2025 (Hunt Valley, MD)

by Jeffrey Brace

More info here: https://ca.syssrc.com/wp/?page_id=105&civiwp=CiviCRM&q=civicrm%2Fevent%2Fin…

2 months, 2 weeks

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VCF East photo gallery

by William Sudbrink

Commodore Z has put up a very nice gallery of photos of VCF East 2025: https://www.commodorez.com/VCFEXX/index.html Bill S. -- This email has been checked for viruses by Avast antivirus software. www.avast.com

2 months, 2 weeks

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RK11-D register address assignment

by Jos Fries

The "RK11-D and RK11-E moving head disk drive controller manual" (EK-RK11D-MM-002) states in par. 2.5 (Installation Procedure) that the register and vector addresses of a RK11-D can be configured by "seven interrupt vector address jumpers and eight address selection jumpers of the M7257". The manual however doesn't state the address range that can be configured by these jumpers and refers to engineering drawing D-CS-M7257-0-1 for that information. I found these drawings in the RK11-D Engineering Drawings but cannot find information in them on the valid address ranges. Therefore my question: what is the address range a RK11 controller can be configured for?

2 months, 2 weeks

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