- vcf-midatlantic - lists.vcfed.org

VCF Museum - Microcomputer slots, S-100 to Apple II to IBM PC, Lou Eggebrecht
by Douglas Crawford 26 May '23

26 May '23

This is the first in what I expect to be a series of posts that highlight subject I/We are thinking of at the museum. In the museum, one of our talking points- a "sub tour" in the museum, highlights concepts of interconnects, from back planes to buses. Bus slots are best represented currently in the micro era exhibits on S-100, Apple II, and the PC. One idea that is probably coming is to have a whole slew of labeled add-in boards on the wall to show how significant the ability and the practice of upgrading a microcomputer was. Slots were important to make these machines versatile and created entire sub industries around each machine that had slots. I'm less versed in the slot systems of the minicomputers; I imagine a certain amount of this dynamic occurred there too. I'd like to share a bit of lore on the IBM PC bus, as this, I find, is lesser known in the hobby. The father of the IBM PC ISA bus is Lou Eggebrecht, and its a great story. He wrote the book, literally, on the IBM PC ISA Bus. https://archive.org/details/interfacingtoibm00egge I just bought a copy. We'll have this in the museum. After the PC was launched, a situation happened between him and IBM and they "parted ways". A short interpretation might go along the lines that IBM perceived Mr. Eggebrecht was capitalizing too much personally on the ISA bus. My reference is "Blue Magic - The People, Power and Politics Behind the IBM Personal Computer" by James Chposky and Ted Leonsis. I don't know his whole career after IBM. I do know he went on to be an influential person at Commodore, ICS and Broadcom. Here's a period piece on him at Commodore (https://amr.abime.net/review_51617) He seemed to follow along with moves of Mr. Hock Tan. Hock Tan is the CEO that presided at Commodore at the end of line, selling off the assets I think. Hock Tan then came to ICS (Integrated Circuit Systems), a Valley Forge-based fabless mixed signal semiconductor designer with products revolving around phase-locked loops. Of interest to most of our hobby--- ICS was started by Ex-MOS process engineer Ed Arnold in the late 1970s. ICS had a number of ex-Commodore personnel on staff. Mr. Eggebrecht I believe was on the board of ICS for while, and this is where I had a chance to meet him in the late 1990s. At the time I only knew he had some involvement with the IBM PC. He was very likeable; humble, warm, and gracious. Mr. Eggebrecht was ideal to have on the board at ICS - who's chief products were the timing generators for the Intel processors and chipsets at the time. Hock Tan went on to IDT (as did I) when he sold ICS to IDT and then to Avago (I did not). Hock Tan orchestrated the huge merger of Avago and Broadcom. I mention this, because, not surprisingly, Lou Eggebrecht served on the board of Broadcom for some time too. He would be a great speaker at a VCF! :-O I hope his oral history gets taken too.

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VCF Museum - Microcomputer slots, S-100 to Apple II to IBM PC, Lou Eggebrecht
by Herbert Johnson 26 May '23

26 May '23

I read Doug's post, and subsequent posts, and started to write a response that filled in on a few points. Such as, actual S-100 bus history. Or, why a "slot" isn't quite a bus, and the history of that. And, how IBM's PC bus isn't quite like MITS's Altair Bus - which wasn't quite "S-100". That became a lecture, and it's not useful or polite to post a lecture. So I created a Web page instead, and I'm posting a link to that, for those interested in a little more background. While it's my opinion, it's a technically informed one; some history can be argued of course. It's also on-the-fly and a bit rough. http://www.retrotechnology.com/herbs_stuff/bus_history.html The point relevant to this discussion, is to flesh-out some of the background that Doug references. I hope it informs his intended display. It's certainly a good idea, to display and describe general features of vintage computers. One of them is a bus architecture, or maybe the lack of one, why such things occur, and their consequences. My interest in S-100 architectures is certainly a consequence. Much of my Web site is devoted to S-100 computers. Others who have posted, have sites or interests in specific brands or architectures. I'm informed by their responses in my document. Thanks to all and I hope I have some useful considerations in my offline response. Regards Herb Johnson -- Herbert R. Johnson, New Jersey USA https://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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August Repair Workshop & InfoAge Volunteer Cookout
by Jeffrey Brace 26 May '23

26 May '23

The August repair workshop will be August 26 & 27. Signup is here: https://docs.google.com/spreadsheets/d/1fWMqLQ_8wqgUHlUJMqLlH84z3CPpOzc2Tb-… There is a volunteer cookout run by InfoAge for all the volunteers on August 26. So we are invited. I need a count of who is coming, so please sign up on the Repair Workshop list to let me know that you are coming. Likely it will be burgers, hot dogs, soft drinks. There is no cost to volunteers. Volunteers and their families will be coming. Probably it will be around 6PM, but details will be forthcoming. Thanks! Jeff Brace VCF National Board Member Chairman & Vice President Vintage Computer Festival East Showrunner VCF Mid-Atlantic Event Manager Vintage Computer Federation is a 501c3 charity https://vcfed.org/ <http://www.vcfed.org/> jeffrey(a)vcfed.org

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Usagi Electric (Dave Lovett) visits Computer Museum @ System Source (20 Minute Video)
by rar 25 May '23

25 May '23

YouTube creator, David Lovett, (Usagi Electric) was here in Baltimore last week and filmed some of the highlights of the museum. He chose a few items that we rarely talk about in addition the items we usually show. https://www.youtube.com/watch?v=iqiFOkJ_Kbg We are shipping him one of our Bendix G-15s for him to restore. Can't Wait! Bob Roswell https://museum@syssrc.com 410-952-9140

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Speaking of youtube videos - my museum vid.
by Dave Shevett 25 May '23

25 May '23

Finally edited this together - a tour of the museum when I was down there for VCF east. https://youtu.be/qCDxU6aJC3U -- Dave Shevett shevett(a)pobox.com

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I tube, you-tube, we all tube for ...
by Jeffrey Jonas 25 May '23

25 May '23

Just making sure everyone knows of 1) Bill Mauchly's videos https://www.youtube.com/@BillMauchly/videos 2) The wonderful followup to "The Secret Life Of Machines" is the 'Secret life of Components' https://www.youtube.com/@timhunkin1/videos This channel is about Tim Hunkin's work. It includes his TV work, arcade machines, public clocks and his recent youtube 'Secret life of Components' videos. 3) for purely mechanical devices, see Brad Litwin https://www.youtube.com/@BLitwin/videos http://www.bradlitwin.com/ These are the works of Bradley N. Litwin, kinetic sculptor, musician, self-made madman. Here, you will find all kinds of mechanical stuff, ranging from the miniscule to pieces that fill a proscenium stage. And, Brad is the inventor and maker of MechaniCards, an affordable collection of "mechanundras," designed to be mailed, presented as unusual gifts, or just zoning out, while playing with them, on your coffee table. and so much more! -- jeff jonas

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First TV Show Home Computer?
by Douglas Crawford 23 May '23

23 May '23

(Computer in the home) Munsters beat out Batman?! Claimed to be a UNIVAC https://youtu.be/aa2nCVke2XY?t=219

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Re: [vcf-midatlantic] Ohio Scientific 440 Video Board
by Bill Degnan 23 May '23

23 May '23

I almost surely have schematics and specs for all of this. What should I look for to assist? Or stop by at your convenience. I have reorganized the OSI stuff to make it easier to use and I have been planning to explore the 400 series stuff. Bill On Mon, May 22, 2023, 8:02 PM Alexander Pierson via vcf-midatlantic < vcf-midatlantic(a)lists.vcfed.org> wrote: > Bill & Bill, > Mr. Degnan, I had seen your 400 board photo on vintagecomputer.net, which > I used as a reference during the construction of my replica from > glitchworks (which is now running!), but I had not seen the rest of the > image set including the 440. That will be helpful as a reference, as I've > only found photos of 4 other units out there. Seems yours has the last two > RAM sockets populated for color. > > > The documents for both the 440 and 420c available online from osiweb & > Mark's OSI archive are ones provided by Mr. Dromgoole himself, so thank you > for having uploaded those -- without them, I'd be up a creek. Also, good > to know about Mike's ASCII keyboard adapter. > > > I've also come across what might be an example of an original Challenger > with a 440 and a 420c on DigiBarn's page. They're the cards farthest from > the nameplate. > https://www.digibarn.com/collections/systems/challenger/page_01.htm > > I wish attending a workshop was in the cards for me, but the distance/time > tends to clash with my work schedule. > > > Thank you, > -Alexander 'Z' Pierson > On Monday, May 22, 2023 at 01:41:05 PM EDT, Bill Degnan via > vcf-midatlantic <vcf-midatlantic(a)lists.vcfed.org> wrote: > > Maybe I will bring my osi 400 stuff to the upcoming vcfed workshop, If I > can go and have coverage at the museum then > B > > On Mon, May 22, 2023, 12:43 PM Bill Dromgoole via vcf-midatlantic < > vcf-midatlantic(a)lists.vcfed.org> wrote: > > > You just need an ascii keyboard with TTL level outputs for the 440 video > > board. > > The input is enabled for one micro second every five milliseconds by the > > OSI 65V ROM. > > This means you need a keyboard strobe pulse about 10 milliseconds long > for > > it to work. > > You can use M. Willigals PC keyboard to apple 1 adapter board for testing > > purposes if you want. > > The early version only had a pulse width of 125 microseconds though. > > I had to use a 74ls123 with a 15K resistor and a 1.1 microfarad capacitor > > between the adapter and the 440 to get the correct pulse width. > > > > He no longer sells the board but can build your own. > > http://www.willegal.net/appleii/appleii-kb-int.htm > > > > Bill > > From: Alexander Pierson via vcf-midatlantic > > Sent: Monday, May 22, 2023 9:37 AM > > To: vcf-midatlantic(a)lists.vcfed.org > > Cc: Alexander Pierson > > Subject: [vcf-midatlantic] Ohio Scientific 440 Video Board > > > > > >

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Re: [vcf-midatlantic] Ohio Scientific 440 Video Board
by Bill Dromgoole 23 May '23

23 May '23

You just need an ascii keyboard with TTL level outputs for the 440 video board. The input is enabled for one micro second every five milliseconds by the OSI 65V ROM. This means you need a keyboard strobe pulse about 10 milliseconds long for it to work. You can use M. Willigals PC keyboard to apple 1 adapter board for testing purposes if you want. The early version only had a pulse width of 125 microseconds though. I had to use a 74ls123 with a 15K resistor and a 1.1 microfarad capacitor between the adapter and the 440 to get the correct pulse width. He no longer sells the board but can build your own. http://www.willegal.net/appleii/appleii-kb-int.htm Bill From: Alexander Pierson via vcf-midatlantic Sent: Monday, May 22, 2023 9:37 AM To: vcf-midatlantic(a)lists.vcfed.org Cc: Alexander Pierson Subject: [vcf-midatlantic] Ohio Scientific 440 Video Board

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August Repair Workshop Rescheduled to August 26 & 27
by Jeffrey Brace 22 May '23

22 May '23

Unfortunately a gremlin deleted our reservation for the August repair workshop back in January. Some other group has since reserved for our originally scheduled weekend. So the new date is August 26 & 27. *Signup for August*: https://docs.google.com/spreadsheets/d/1fWMqLQ_8wqgUHlUJMqLlH84z3CPpOzc2Tb-… *Other dates for Repair Workshops:* *Signup for June*: https://docs.google.com/spreadsheets/d/1Y17roR2xP75sq5kjbv8jcVPk-a3vCVjWdmT… *Signup for July:* https://docs.google.com/spreadsheets/d/1TJJxdL8skd7giR1miP-5AKMHwoBSqU7gse-… *Signup for October*: https://docs.google.com/spreadsheets/d/1skx8EEXuJl2fUdNGrDIeJO8eekSQQI-ciyT… *Signup for November*: https://docs.google.com/spreadsheets/d/1gcb3OQ60zfuZpNcXkqi-rUwvlVeYLZF4t1s… Thanks! Jeff Brace VCF National Board Member Chairman & Vice President Vintage Computer Festival East Showrunner VCF Mid-Atlantic Event Manager Vintage Computer Federation is a 501c3 charity https://vcfed.org/ <http://www.vcfed.org/> jeffrey(a)vcfed.org

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