- vcf-midatlantic - lists.vcfed.org

Re: [vcf-midatlantic] Monitor needed for museum
by Evan Koblentz 26 Aug '17

26 Aug '17

Hey look! http://www.robotshop.com/en/raspberry-pi-vga-adapter.html Ethan Dicks (VCF East frequent PDP-8 exhibitor) turned me on to this. He teaches Pi classes at his local hackerspace. He said that in his experience the Pi usually "just works" to detect the video type, but that it's more reliable when you edit the config file. For 7 bucks I am definitely buying us one. I already have a low-profile widescreen VGA LCD at home that's the perfect size for our application. (VCF's existing supply of VGA LCDs are all square-shaped.) All's well that ends well.

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anyone want a mac plus $50
by william degnan 24 Aug '17

24 Aug '17

https://delaware.craigslist.org/sys/d/1986-macintosh-plus-computer/62416887… This is down the road from me, near Newark, Delaware over the PA line (rte 896 before rte 1). Bill

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FS: Industrial 486 ISA Computer with 8 GB DOM, Ethernet, MS-DOS 6.22, Utils
by systems_glitch 24 Aug '17

24 Aug '17

Description + pictures on the VC Forums: http://www.vcfed.org/forum/showthread.php?59315-FS-Industrial-486-ISA-Compu… This little box started life as an 8-port terminal and application server. It came to me with only the CPU board, and a crashed hard disk that looked like it had a plain DOS install on it anyway. I cleaned it up as described in the forum thread, but I'm thinking I'll sell it as my PICMG box is effectively the same thing but more flexible. Thanks, Jonathan

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Fake 7400-series memory
by Herb Johnson 24 Aug '17

24 Aug '17

> That was a rather interesting read. It's like a combination > of archeology and technology. - Joe Oprysko Right. That's what early vintage computing looks like - kinda. ;) Editorial follows, for those interested. Otherwise: thanks for this glimpse into a corner of chip-collecting. - H Doing some Web "archeology" found the originator of the decapitated chip. It's part of a recent project by Robert Baruch which he calls "Project 54/74" and hosted on YouTube and a wiki at project5474.org, and his Twitter account. He extracts chip die from original 7400 (and the industrial/military version 5400) logic chips, for annotation and imaging; then reverse engineers the schematic. He seems to be doing other vintage-computing stuff as well, with new S-100 boards and 3D printing, very 21st century. Tracing out chip-die sounds like rocket-science; but it's a matter of knowledge and tedium, recognizing visual patterns and following the likely logic. That's what the "fake" poster Ken Shirriff performed in his deconstruction Web post. TTL gate-level logic is usually described in 7400 documents, but not in detail. EE's in the 70's era (like me) were trained in semiconductors at almost the die level; the detailed knowledge is/was available in other textbooks for IC design specialists. And, it's something done in the microprocessor collecting world; tracing out early CPU dies. There may well be other such projects, for other chips including TTL. And it was professionally done in the era as literal reverse-engineering; competitors looking for ways to produce copies, learn design techniques, and so on. "Archeology and technology" overlap considerably; archeologists try to reverse engineer how structures or tools, homes, weapons were made. To me this is another example of what I call preservation by restoration and repair and Web publishing. I work at the S-100 board and chip level, not at the die level. As do others in this email list. Herb Johnson -- Herbert R. Johnson, New Jersey in the USA http://www.retrotechnology.com OR .net

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Fake 7400-series memory
by Evan Koblentz 24 Aug '17

24 Aug '17

http://www.righto.com/2017/08/inside-fake-ram-chip-i-found-something.html

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FS: Prototype Glitch Works Ohio Scientific Universal RAM Board
by systems_glitch 23 Aug '17

23 Aug '17

link: http://www.ebay.com/itm/272817996082 I'm selling some of the prototype boards for my GW-OSI-RAM1 Universal 128 KW RAM board. This board provides up to 128 KW (64 KW without memory management) of static RAM on the Ohio Scientific bus. It supports a 12-bit word size and is compatible with the Ohio Scientific 560Z "Processor Lab" in PDP-8 mode. It also includes a prototyping area, and a header for mezzanine display boards. Included with the auction is a Hex Lamp Register and an Octal Lamp Register, which can be mounted directly to the GW-OSI-RAM1 or used remote on a cable (e.g. for a front panel). This is a pre-production board, the most significant difference is that it lacks a corner mounting hole, which can be drilled if needed (no circuit traces run under its location). The other differences are minor. See auction link for full description! Thanks, Jonathan

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OT: my own Pi
by Evan Koblentz 22 Aug '17

22 Aug '17

Successfully booted my Pi Zero W into Raspbian tonight. Connected it to my living room TV (native HDMI) plus a keyboard and mouse. Now what? It's a little Linux computer.... although Corey says I shouldn't think of it that way. No need to serve tablet content at home :) so I could use (real) ideas about what to do with it. ________________________________ Evan Koblentz, director Vintage Computer Federation a 501(c)(3) educational non-profit evan(a)vcfed.org (646) 546-9999 www.vcfed.org facebook.com/vcfederation twitter.com/vcfederation instagram.com/vcfederation

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Monitor needed for museum
by Evan Koblentz 21 Aug '17

21 Aug '17

Everyone, We need an HDMI monitor for a permanent connection to the Pi that powers our tablet content. Ideally it should be smaller than 19" (so it can fit on a rack shelf) but not less than, say, 15" (so we can actually read it). I tried using a known-working HDMI-VGA adapter. But it's not supported by the Pi. Does anyone have a suitable screen to donate, or can someone buy it for us? This is something we need quickly. ________________________ Evan Koblentz, director Vintage Computer Federation A 501(c)(3) educational non-profit Evan(a)vcfed.org +1 (646) 546-9999 www.vcfed.org facebook.com/vcfederation instagram.com/vcfederation twitter.com/vcfederation

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OT: Pi RCA conversion
by Evan Koblentz 21 Aug '17

21 Aug '17

I'm reading this: https://www.modmypi.com/blog/how-to-add-an-rca-tv-connector-to-a-raspberry-… I cut one end off a generic yellow-tipped RCA wire and stripped back the insulation. Insider there's one insulated wire (yellow) and one bare copper wire. Which is the positive/negative? Rest assured, I'm experimenting on my own Pi, not the museum's. :) ________________________________ Evan Koblentz, director Vintage Computer Federation a 501(c)(3) educational non-profit evan(a)vcfed.org (646) 546-9999 www.vcfed.org facebook.com/vcfederation twitter.com/vcfederation instagram.com/vcfederation

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Re: [vcf-midatlantic] OT: Pi RCA conversion
by Evan Koblentz 21 Aug '17

21 Aug '17

> Center conductor is video. > Shield is ground. Some would call it negative. Thanks! Found it on Google but I appreciate the confirmation from someone I know and trust.

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