- vcf-midatlantic - lists.vcfed.org

Settings for Jan (1/15 repair session)
by Neil Cherry 16 Jan '23

16 Jan '23

First, I had a great time with all the VCF folks on Sunday at CDL. I met new people and had fun getting distracted with this and that related to vintage computers. :-) I was working with Jan on her IBM PC/AT and getting the setting for the cards. Well my memory isn't so good but I did find a useful site that will help. http://dosdays.co.uk/topics/io_addresses_irq_dma.php If the network card can be set for IRQ 9 that's a good spot. PC/XTs could use IRQ 2 but that's handling the IRQs 8-15 and IRQ 9 is it's replacement on the AT. IRQ 3 is com port 2 and IRQ 4 is com 1. I got them backwards. The above web site has good references for the IO ports. This get muddled depending on the settings of the other cards. I seem to recall that many PC, XTs and ATs didn't have an LPT2 and I don't recall seeing a sound card in your machine. -- Linux Home Automation Neil Cherry kd2zrq(a)linuxha.com http://www.linuxha.com/ Main site http://linuxha.blogspot.com/ My HA Blog Author of: Linux Smart Homes For Dummies KD2ZRQ

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Breakfast tomorrow at Blue Swan at 9AM
by Jeffrey Brace 14 Jan '23

14 Jan '23

If you’re in, let me know. -- ========================================= Jeff Brace VCF National Board Member Chairman & Vice President Vintage Computer Festival East Showrunner Vintage Computer Federation is a 501c3 charity https://vcfed.org/ <http://www.vcfed.org/> jeffrey(a)vcfed.org

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Repair Workshop reminder 1/14 & 1/15, 2023
by Herbert Johnson 13 Jan '23

13 Jan '23

Weather looks good for me to drive up Saturday, not Sunday. David Gesswein kindly accepts my request to read an MFM drive I have. I have some parts to pick up from various people. I'll bring a simple 6809 kit to assemble with some of those parts. And I'll float around to see if I can help others with repairs. Regards Herb Johnson -- Herbert R. Johnson, New Jersey in the USA http://www.retrotechnology.com OR .net preserve, recover, restore 1970's computing email: hjohnson AT retrotechnology DOT com or try later herbjohnson AT comcast DOT net

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Repair Workshop reminder 1/14 & 1/15, 2023
by Jeffrey Brace 13 Jan '23

13 Jan '23

Just reminding everyone that there is another repair workshop this coming Saturday and Sunday January 14 and 15. Signup here: https://docs.google.com/spreadsheets/d/1-CzOmtnbGWwcNc53ewymcAe1Zt5xNTow4cm… ========================================= Jeff Brace VCF National Board Member Chairman & Vice President Vintage Computer Festival East Showrunner Vintage Computer Federation is a 501c3 charity https://vcfed.org/ <http://www.vcfed.org/> jeffrey(a)vcfed.org

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Re: [vcf-midatlantic] Repair Workshop reminder 1/14 & 1/15, 2023
by Neil Cherry 13 Jan '23

13 Jan '23

On 1/13/23 10:34, Jonathan Sturges via vcf-midatlantic wrote: >> Reset sees a low (/RST) every 3s. So there is a watchdog timer setup. I traced it back to a MC14584B (yea!) which is a hex >> schmidt trigger (what? 😉 ). So I have to do some more tracing but the MC14584B is socketed so I'll build a manual reset >> circuit and figure out what is going on later. > Ahh, the Schmidt trigger. Pairs of those gates are good for fixing marginal amplitude issues and/or "squarifying" a > less-than-square waveform. If the RST signal looks well-formed, then the problem is probably upstream of the Schmidt trigger. I pop'd the chip out and soldered up a resistor, cap and NO PB on a carrier. I'll search for the watchdog later. That solves that problem for now. The new troublemaker is the USB dongle doesn't have enough oomph to pull up the 6803 Rx pin. I'm going to drive it with either a NOT or NAND gates or an opto to drive it a bit more. -- Linux Home Automation Neil Cherry kd2zrq(a)linuxha.com http://www.linuxha.com/ Main site http://linuxha.blogspot.com/ My HA Blog Author of: Linux Smart Homes For Dummies KD2ZRQ

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Re: [vcf-midatlantic] Repair Workshop reminder 1/14 & 1/15, 2023
by Jonathan Sturges 13 Jan '23

13 Jan '23

-----Original Message----- From: Neil Cherry via vcf-midatlantic <vcf-midatlantic(a)lists.vcfed.org> Subject: Re: [vcf-midatlantic] Repair Workshop reminder 1/14 & 1/15, 2023 > Reset sees a low (/RST) every 3s. So there is a watchdog > timer setup. I traced it back to a MC14584B (yea!) which is a hex > schmidt trigger (what? ;-) ). So I have to do some more tracing but the > MC14584B is socketed so I'll build a manual reset circuit and figure out what is > going on later. Ahh, the Schmidt trigger. Pairs of those gates are good for fixing marginal amplitude issues and/or "squarifying" a less-than-square waveform. If the RST signal looks well-formed, then the problem is probably upstream of the Schmidt trigger. -Jonathan

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Jan 2023 Repair Workshop Info
by Jeffrey Brace 12 Jan '23

12 Jan '23

Signup for January 2023 Repair Workshop here: January 2023 Repair Workshop Signup Sheet <https://docs.google.com/spreadsheets/d/1-CzOmtnbGWwcNc53ewymcAe1Zt5xNTow4cm…> Spaces are first come first serve to the CDL space. Limited space available. Sign up to guarantee a space in your preferred area!!! *DATES*: January 14 & 15, 2023 *LOCATIONS:* InfoAge: 2201 Marconi Road, Wall Township, NJ Building 9059 (CDL Hackerspace - Formerly IXR) TIME: Saturday START time == 10 A.M. END time == 11PM. Sunday START time == 10 A.M. and END == 5 P.M. *SIGNUP HERE!*: Signup sheet Click HERE <https://docs.google.com/spreadsheets/d/1-CzOmtnbGWwcNc53ewymcAe1Zt5xNTow4cm…> ! Face Masks are required for non-vaccinated people. Vaccinated people have the option to wear masks, but they are highly recommended. *COST:*- $15 per person, PER day. This money goes to InfoAge and CDL. - $25 per night for those wanting to stay overnight (Money goes to InfoAge). Please pay ME upon arrival. Cash or PayPal is acceptable as payment. Ask ahead of time if you need to use a credit card. *OVERNIGHT*: Bring your own pillow, blankets, soap etc. We provide a bed frame and an uncovered mattress. There are showers and a kitchen for your use. - You can pay via PayPal to paypal(a)vcfed.org. or to me via cash or credit card in person. *EQUIPMENT:* - VCF will provide a table and you can use any available electrical outlet. - Bring your own tools, power strips, power cords, and supplies etc. - If you need particular tools that you don't own or particular parts, please post to the list for those going. They may have what you need. Let them know ahead of time. - Let everyone know what project you are working on ahead of time to inspire collaboration. *DRINKS*: You should bring your own. We have a refrigerator in CDL to keep them cold. VCF will buy some water and soft drinks for member use. *FOOD*: *Saturday Night Dinner at 7PM?*: Options: * Brick House Tap and Tavern * MJs * Patrick's Pub * Ottos * Robinson Ale House *Sunday Morning*: Blue Swan Diner *Sunday Afternoon*: Wawa? *PARKING:* Park in the main parking lot, unless you are unloading. Don't park on the lawn. QUESTIONS? PHONE: ( 7 3 2 ) 7 2 2 - 5 0 1 5 EMAIL: repairworkshops AT vcfed DOT org Have fun everyone! ========================================= Jeff Brace VCF National Board Member Chairman & Vice President Vintage Computer Festival East Show-runner VCF Mid-Atlantic Executive Director Vintage Computer Federation is a 501c3 charity http://www.vcfed.org/ jeffrey(a)vcfed.org

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[FS] Really Nice Fully Loaded and Boxed IBM AT with 5153 and 5154 Monitors
by Alexander Jacocks 10 Jan '23

10 Jan '23

All, I just posted this on VC Forum, and wanted to make sure that everyone here saw this listing, as well. Please let me know if you are interested. - Alex https://forum.vcfed.org/index.php?threads/extremely-nice-foully-loaded-ibm-…

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VCF East 2023 Registration Links
by Jeffrey Brace 06 Jan '23

06 Jan '23

In case you missed the previous emails: Exhibitor Registration: https://forms.gle/iKZNPqFPSeobjnau5 Vendor Registration: https://forms.gle/zGsPxCcuDQBXm3fb7 Volunteer Registration: https://forms.gle/UEbiFYvgEiBk9MS27 Speaker Registration: https://forms.gle/yvV311ucBEWXzqpx9 ========================================= Jeff Brace VCF National Board Member Chairman & Vice President Vintage Computer Festival East Showrunner Vintage Computer Federation is a 501c3 charity https://vcfed.org/ <http://www.vcfed.org/> jeffrey(a)vcfed.org

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Re: [vcf-midatlantic] What we can learn from vintage computing
by Jeffrey Jonas 05 Jan '23

05 Jan '23

Bob Jeffway posted: > I co-teach a class at University Of Massachusetts in Amherst > using Bob Applegate's KIM-1 replicas. An interesting choice for sure. Hex keypads & displays are definitely a step-up from toggle switches and individual bits. > We start with machine language programming, then move to an assembler, > and teach all the low-level stuff; address bus, data bus, controls, clock, etc. > and how to interface hardware. Very nice! Ben Eater advocates breadboarding everything yourself, learning every wire along the way: https://www.youtube.com/c/beneater One of my masters' degree pre-reqs was a 68000 lab course with this single board trainer: http://ferretronix.com/tech/sbc/index.html#68k The ROM provided an interactive debugger and a few run-time library calls for print, read, etc. http://ferretronix.com/tech/68k/68k_monitor_notes -- jeff jonas

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