January 2016 - vcf-midatlantic

Interesting OP-AMP Boards
by Systems Glitch 27 Jan '16

27 Jan '16

All, These came in a lot of other plugboard/protoboard bits I picked up: http://imgur.com/a/XUFAJ One has two 741 OP-AMPs, the other two have a single LM311. I'm guessing from the array of hollow pins that they're meant to be wired up with some sort of banana-plug-like jumper system. I'm not sure what they're from. Some sort of analog computer or control system, perhaps? Any ideas? They're single-sided, but everything on the back side is gold plated. Thanks, Jonathan

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Mystery ROM from MITS 88-PMC ROM Board
by Systems Glitch 27 Jan '16

27 Jan '16

I've been going through a lot of my S-100 boards, doing cleaning and testing. Tonight I started on a MITS 88-PMC, which had a ROM in the last socket (locations 0xFF00 - 0xFFFF) with no label. It's not the MBL, DBL, or TURMON. Here's a hex dump from the Dajen SCI monitor: http://pastebin.com/24Gjh2kw It starts with LXI SP, 0xFF13 -- a ROM location. I've seen the trick used elsewhere, to reduce code size by using an in-ROM jump table. Anyone recognize the code? Thanks, Jonathan

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test ... this might our DNS change to the new hoster...
by Evan Koblentz 27 Jan '16

27 Jan '16

I had a message bounce just now, so our DNS change may be underway....

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DNS changes
by Evan Koblentz 27 Jan '16

27 Jan '16

Hopefully this message will get through at some point. :) I logged into the domain zone editor for our new hoster and made the necessary A/MX/TXT entries. That should make this list "just work" when the DNS changes over from GoDaddy to the new company. I'm not sure if that is happening right now (Erik told us it would be soon) or if there's just a hiccup of some sort. Regardless, it would be good and worthwhile when it's done!

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OT: snow storm
by Evan Koblentz 27 Jan '16

27 Jan '16

How did everyone handle the storm? I'm in the heart of the deepest stuff -- 30". Shoveled twice yesterday and once today.

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Re: [vcf-midatlantic] OT: snow storm
by VAXman＠tmesis.org 26 Jan '16

26 Jan '16

Kyle Owen via vcf-midatlantic writes: >I saw a handful of flakes here in mid-Alabama. :) Wow! A state of emergency there. :)

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Important Workshop Jan 30/31 Notes
by Jeffrey Brace 26 Jan '16

26 Jan '16

LOCATION: InfoAge Building 9032A - (2201 Marconi Road, Wall Township, NJ) DATE: Saturday January 30 & Sunday 31 TIME: Start about 10 A.M. on Saturday end whenever. End about 5 P.M. on Sunday. (Starts around 10 A.M. Sunday morning) COST: $10 for all members attending the workshop, which MARCH donates to InfoAge as thanks for providing the space for us. EQUIPMENT: MARCH will provide a table and you can use any available electrical outlet. Bring your own tools, power strips, power cords and supplies etc. DRINKS: You should bring your own. However, I will bring a case of water bottles free for everyone to take. FOOD: You provide your own. We may order pizza or go out to a dinner. Usually we make a decision when everyone gets hungry. PARKING: Park behind the back ramp of 9032A (which is around the building), or in the main parking lot, NOT in the courtyard. Please close the front gate behind you after entering. Not sure of the situation with snow right now near the back ramp. I'm hoping that a lot of it will be melted by Saturday. LOOSE THEME: Commodore 64 and Commodore 1541. Feel free to bring whatever you want, or just watch. There are plenty of people to help and one can learn a lot by watching. HAM RADIO: Martin Flynn said that if anyone is interested he can open N2MO. Let me know if anyone has a desire for it. If you need to contact me, my smart phone is: 732-759-1783. Hope to see lots of you there! :-D Jeff Brace

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FS: MITS 88-VI (RTC) Vector Interrupt and Real Time Clock
by Systems Glitch 26 Jan '16

26 Jan '16

link: http://www.ebay.com/itm/272116893925 This one appears to be pretty early. The silkscreen is black instead of yellow, but it does have a copyright date of 1975, and no solder mask. It includes an early Intel 8214 Priority Interrupt Controller in white ceramic with gold lid and gold leads. I would guess it was assembled in mid-1976 by the IC date codes. You'll need one of these for MITS timesharing BASIC, or if you want to use interrupt-driven I/O devices. I've tested everything on this board except the 60 Hz timebase. That requires modifying your S-100 box to put unfiltered, unregulated 16 VAC on pin 55 of your motherboard, which I didn't want to do. I tested the interrupt controller by writing an initialization routine based off the example in the MITS 88-VI manual, and writing interrupt service routines to display the interrupt level on my IMSAI's programmed output register. Thanks, Jonathan

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Marvin Minsky
by Evan Koblentz 26 Jan '16

26 Jan '16

Father of AI died. http://www.techrepublic.com/article/father-of-ai-marvin-minsky-dies-at-88-l… Coincidence that 1950s project was called "Snarc" which happens to be my domain.

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Girl Scout cookies... vintage computer related!
by Herb Johnson 26 Jan '16

26 Jan '16

About restoring capacitance-keyswitch keyboards, including source materials, and work by several former-MARCH members: http://www.retrotechnology.com/restore/sol_keys.html Metalized Mylar in rolls may be available at "dollar stores" as gift-wrapping. It's just aluminum on Mylar. Snack chip bags, cookie bags as noted, helium balloons, gift wrap - on and on. the challenge is the right "foam" material. Bill Degnan came up with a good material - see my Web site, and his. Herb -- Herbert R. Johnson, New Jersey USA http://www.retrotechnology.com OR .net

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