- cctalk - classiccmp.org

by Robert Marinelli

I've been digging through CHM and bitsavers and haven't found an IMF for 5100 or 5110 yet. It seems a lot of CE material was just not saved. However, I've been tracing execution of ExecROS and the APL ROS - thanks to your excellent emulator and the extracted ROS files this works well. Have learned a few things about the jump tables, I'd imagine that the type 23 files would likely install themselves in high memory and modify an IOCB jump entry to point to the new/patch code. Kind of like how you take over the printer IOCB. One little issue I found with your emulator is behavior of interrupts while in HOLD. Per the APL and BASIC manuals, pressing HOLD while a program is running should pause the output (mostly so you can read the screen before output scrolls up), and then pressing HOLD again is supposed to continue execution. In emu5110 that didn't work, pressing HOLD always stopped but a 2nd press wanders off in to never land (hang or bogus error or junk on screen). While tracing & learning I noticed that if code was being executed from one of the language ROS, HOLD would fail. But HOLD/resume worked fine on an idle machine - idle is a short loop that just blinks the _ cursor at location 0x0200+902 in APL. So looking through the pseudo-schematics/block diagrams in SY31-0552-3 IBM 5110 System Logic there is quite a bit of gate logic on the multiple ROS cards, plenty of wires between them. Maybe, hardware interrupts are held off in hardware when we are doing reads from the language ROS cards. The interrupt bits are properly shown in a register, but nothing detailing gating of interrupt -> CPU. To test the idea I made this change in emu.c: 175c175,176 < check_int(); /* check for pending interrupts */ --- >if(curr_ros==ExecROS) /* if in ExecROS we can HOLD/resume */ > check_int(); /* check for pending interrupts */ and now HOLD works as expected. Norbert's JavaScript port had the same issue with HOLD, he ported the above and confirmed that the HOLD now works properly. As a side note, the MAME emulation (which may have been done independently) has the same problem, likely could use the same fix. Anyone know how to contact the MAME author? There was a lot of interest in the CHM release of APL\360 source along with auto-operator and I've tried contact a few of those folks, we just need one CE or user who kept a box of floppies. -Robert

5 months, 1 week

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50 years of the MOS 6502

by Christian Liendo

https://www.allaboutcircuits.com/news/the-mos-6502-how-a-25-chip-sparked-a-… According to many 50 years ago on September 16, 1975, MOS Technology showed the 6502 at WESCON

5 months, 1 week

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VCFMW20 recap of highlights

by Steve Lewis

VCFMW in Chicago was this past weekend! Flew up with 2 bags, came back with 4 ! Funny thing is, my wife said she was surprised I didn't come back with anything extra - well, I shipped those extra 2 bags and they haven't shown up yet. Gives me one day to come up with a cover story! :) There is so much going on at the Chicago VCF - I don't think any individual can cover the whole thing. Instead of a blog, this time I'm trying a "video photo album" to cover some of the highlights that I was able to see. Search Xiphod's Photo Album of Vintage Computer Fest (no commentary) - VCF Chicago 2025 or https://www.youtube.com/watch?v=ld1CXUTusDI or https://rumble.com/v6z4aia-xiphods-photo-album-of-vintage-computer-fest-no-… Mainly my goal was to pick up a POLY-88 that folks have been helping to restore off-and-on over the past 18 months. They got it going, so that was one of the shipments back. The other was an Apple TAM at too good a price to pass up. (and yes, wife already knows they are coming) If it's any indicator: come Sunday afternoon, merchants were fairly eager to sell at any offer (some announcing that anything unsold would go straight to scrap - maybe that's a ploy, but there were some under $10 bargains to be had, a kind of "everything must go" vibe). - Steve

5 months, 1 week

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Fun with PDP11 Assembly Language

by Martin Eberhard

I just love the PDP11's assembly language. I needed a super-tight subroutine to print a 16-bit value as 6 octal digits. This is as tight as I could make it, 16 words (including writing to the serial port, which takes 5 words). Can you beat it? ;*** Subroutine ************************* ;Print a 16-bit value as 6 octal digits ;Calling Sequence: ; jsr PC,PROCT6 ;On Entry: ; R2 = value to print ;Trashes R1,R2 ;**************************************** PROCT6: mov #100030,R1 ;Digit loop ends when '1' lands in C ;..'30' makes it ASCII sec ;All done when this is in C again ;Extract a digit and convert it to ASCII. Check for done. 1$: rol R2 ;Shift digit out of R2 & into R1 beq 3$ ;Return when done rol r1 ;Build next octal digit bcc 1$ ;Done when c = shift pattern bit ;Write digit to the serial port 2$: tstb @#CTXSTA ;Wait for transmitter (clears C) bpl 2$ movb R1,@#CTXDAT ;Transmit now ;Next digit mov #020006,R1 ;Digit ends when "2" lands in C. ;Printing ends when "sec" bit ;..leaves R2. '6' makes ASCII br 1$ 3$: rts PC Martin E.

5 months, 1 week

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Ohio scientific boot discs

by George Rachor

Looking for both 8 inch and 5.25 inch boot media. Sent from my iPhone george(a)rachors.com

5 months, 2 weeks

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Huntsville Microsystem HMI-200 emulators

by Tony Jones

Crazy long shot. I just picked up a HMI-200-64180 for $75 shipped. Curious if anyone has the manual and software for it? There is some very limited info on bit savers but nothing for the 64180. I'd also possibly be interested in picking up the 6809 version if anyone has one they no longer need and the price is fair. https://web.archive.org/web/19980206071507/http://www.hmi.com/200.html Thanks

5 months, 2 weeks

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Large language model (LLM) Web Scrapers

by Bill Degnan

For those of you who run vintage computing-related info sites, have you noticed all of the LLM scraper activity? AI services are using the LLM scrapers to populate their knowledge bases. At any given moment 5-10 of them are active on vintagecomputer.net. It’s funny, when I ask an AI about something vintage computing-related, something obscure, I can trick into giving me an answer from my own site. I have actually had to modify the site code to manage the traffic, to improve efficiency. But they’re not going after just my site, these scrapers are absorbing copies of the entire WWW. I wonder how long the WWW will remain open, it would be a bummer if I found copies of my site elsewhere. Bill

5 months, 2 weeks

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Need a Connectix quick cam?

by Van Snyder

I have a Connectix quick cam. The on ly label says FCC ID LKD1. The connector is a mini-DIN that looks like a PS-2 mouse or keyboard plug. Do you need it?

5 months, 2 weeks

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Re: [List] Re: Fun with PDP11 Assembly Language

by donald donaldwhittemore.com

You want blinky lights? Try this. 😊 https://www.chilton-computing.org.uk/ca/jpgs/195_engineers_console.jpg

5 months, 2 weeks

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Re: CTOS Ethernet EDL software

by Alexei Iliasov

The driver package (B25-PDL_CTOS_Ethernet_Packet_Driver_3.7.0) also has drivers for ACCTON 1660 and 3COM 3C509 - you need to uncomment them in JCL file. I have the Accton card installed and detected in dos (and confirmed IRQ and base address) on SG3000 platform but activating the driver always crashes CTOS to core dump. The only suspect bit “Shared memory” which appears to be boot room address and this is not installed on my card (socket missing). Wonder if anyone had success with the driver?

5 months, 2 weeks

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