June 2021 - vcf-midatlantic

Re: Original Macintosh Architecture Questions
by MikeWillegal 24 Jun '21

24 Jun '21

I agree that the original Macintosh (128K) is very painful to use, especially if you try to use it with only the single floppy drive that came with it. Saying it has a poor system design without understanding the design constraints that the developers were faced with, is doing them a disservice. 1) Hardware cost was critical. Apple already had the Lisa. The Macintosh was intended to get the Lisa GUI to an affordable price point that would encourage mass market adoption. The cost goal... a) Limited the system to 128K of DRAM and 64K of ROM. b) Floppy drive only for mass storage. 2) The designers were challenged with implementing a fairly complex GUI a) To make the feature set fit within the available memory, the designers had to implement a paging system to pull system features off of floppy as needed. This degraded performance a great deal, but the only other design choice they had was to reduce the feature set. Once more memory and a SCSI hard drive were added with the release of the Macintosh Plus, the user experience with the same basic hardware and software system was transformed into a very positive one proving the basic system design was good. My opinion is that marketing pressures required that the system to be released before the technology for a high performance system of this type was really affordable. Though significantly enhanced over the years, the same basic architecture lived on until the release of OS/X in 2001, which is not a bad run for a system which was originally designed to work on hardware with such significant limitations. regards, Mike Willegal

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Museum Report 2021-06-23
by Jeffrey Brace 24 Jun '21

24 Jun '21

About a dozen visitors today, which means that summer visitors have begun. Normally there are very few visitors on Wednesdays, but in the summer we get a decent number. The first two visitors were an older couple and their grandson from Florida. He specified to his grandfather that at the top of his list of things to do was to come visit our museum. He was a finance major, but had learned to program in the "R programming language". I had never heard of this, but in any case I explained to him how computers worked, and the history of computers. He was fascinated. He stayed about 2 hours and I had him try some BASIC programming. He loved it! There was another visitor who was Bulgarian and recognized the Apple 2 clone that we had in the museum. She actually knew what it was and where it was manufactured and some history. Her son tried out some BASIC programming on it and stayed for over an hour. There were some other visitors who spent about 40 minutes there, but it became hard to help everyone with three groups of highly interested people. There were 3 last minute visitors, but the girl really liked that most of our computers were hands on because many museums don't allow that. She really enjoyed using them. Overall a good day at the museum. ========================================= Jeff Brace Vice President & Board Member Vintage Computer Festival East Show-runner Vintage Computer Federation is a 501c3 charity http://www.vcfed.org/ jeffrey(a)vcfed.org

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Ampex Computer
by Douglas Crawford 24 Jun '21

24 Jun '21

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Homebrew Computer Systems from Bob the donor
by Jeffrey Brace 24 Jun '21

24 Jun '21

>From "Bob the donor": "{FirstComputerAssembled.jpg} is what it looked like in working order, not just the box of parts I sent with bernie. The rocker switches were for entering the boot-loader for the cassette interface, which used a 565 PLL to convert the FSK audio to bits for the UART. IIRC, it used the same tones as were used on the ham bands for TeleType chats (because I also did that). {FirstComputerCircuitBoardsTop.jpg} This was my first computer because I was introduced to the MOS Tech 6502 in 1975 and thot it was Really Neat. That IC cost me $25 back then; it's the 40 pin white ceramic item on the 'middle' board. The half board, far left, is the cassette interface. To its right is the memory board (note the 2102s, partially installed at this point). There was only 2 KB of RAM, both because of the price and also my rather small programs. Various 'glue bugs' are below the RAM and on the next-right board with the processor. Below the uP are parallel interface ICs and the UART. The rightmost board is the video generator, which used a character-generator IC (the largest bug). It required another 2 KB of 2102s, used in two banks that alternated access, because they were so slow. IIRC, the display was 32 lines of 64 characters. I later removed this part, added a UART and powersupply so it worked as a standalone video display. That was in the box of parts, and should still produce serial-to-text. {FirstComputerCircuitBoardWiring.jpg} Is pretty self-explanatory. A mouse would be right at home! I added a few more wires every evening after it was too dark to continue finishing the house construction. Entering the boot-loader every time quickly became a bother so I soon added some NiCads and a small secondary powersupply to keep the main 2KB alive. It was quite a project for how little I did with it; a word processor that could output thru a Model 19 TTY, and also display ham RTTY when I didnt want the noise of the 19. It turned out that I was far more interested in building than in coding, which is why this computer didnt last and you got only a box of some parts of it. The computer in the metal case is an Apple 2 clone board. As you've discovered, I had to 'bend' the board to make it fit the neat enclosure. The price of Apple (or any) 5.25" drives was high, which is why I 'went hardware' again and installed an 8-Track drive and circuitry to make use of it. A larger pulley on the motor provided a faster tape speed (probably around 8 or 9 ips, but I dont remember exactly), dual UARTS read/write to the stereo head (writing square waves at this speed required something like 45 volts IIRC). This required special code, which was in the battery-backed CMOS RAMs that replaced the original Apple ROMs. I copied the useful parts of those ROMS into the RAM so the computer still behaved like an A-2, but my code and the 8-track 'imaged' the RAM and system state, then restore it all on demand. No doubt the battery is long dead from decades in storage, so it's all junk now. As bernie and I were loading it into his car, I noticed the back-panel connector for a paper-tape drive. I no longer have that or I would have included it. So far, I have not found any code listings or diagrams, but will forward anything that turns up." Here are the pictures folder for anyone interested with the new pictures added: https://drive.google.com/drive/folders/1DhjdsPnDN9s5vkCTalxUilHZGvctiVtt?us… ========================================= Jeff Brace Vice President & Board Member Vintage Computer Festival East Show-runner Vintage Computer Federation is a 501c3 charity http://www.vcfed.org/ jeffrey(a)vcfed.org

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Bernie S paid a visit!
by Jeffrey Brace 24 Jun '21

24 Jun '21

Bernie S paid a visit on May 16 at the very end of our repair workshop. He had brought some items for Dmitry. One thing was a custom built 6502 system with all sorts of wires. Another one was a custom built Apple // clone. Very interesting to see all these items. Sorry this is so late, but I've been busy planning for VCF East. Here are some pictures of the items: https://drive.google.com/drive/folders/1DhjdsPnDN9s5vkCTalxUilHZGvctiVtt?us… ========================================= Jeff Brace Vice President & Board Member Vintage Computer Festival East Show-runner Vintage Computer Federation is a 501c3 charity http://www.vcfed.org/ jeffrey(a)vcfed.org <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai…> Virus-free. www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai…> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>

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Saw this and thought this list is exactly the target audience.
by Mark Whittington 23 Jun '21

23 Jun '21

[image: image.png] Not sure how the list handles embeds, so here's a link: https://imgur.com/a/gsSGV1a

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Re: [vcf-midatlantic] Laserdisk transfer to digital?
by Dave McGuire 22 Jun '21

22 Jun '21

Frequently this is not the case, though, and it's not the case here. Matt is a professional video archivist; he wrote the book on this. -Dave On June 21, 2021 3:45:45 PM Sentrytv via vcf-midatlantic <vcf-midatlantic(a)lists.vcfed.org> wrote: > ---------- > Re: [vcf-midatlantic] Laserdisk transfer to digital? > From: Sentrytv sentrytv(a)yahoo.com > Date: Jun 21, 3:45 PM > To: vcf-midatlantic vcf-midatlantic(a)lists.vcfed.org > > As usual, there is a complicated answer and way to do things > and > there is a simple answer and way to do things. > > Somewhere in between is the correct way to do this. > > JM2C > > Sent from: > My extremely complicated, hand held electronic device. > >> On Jun 21, 2021, at 1:03 PM, Alexander Jacocks via vcf-midatlantic <vcf-midatlantic(a)lists.vcfed.org> wrote: >> >> Since Matt has offered, and he has the expertise, I think that we should >> have him do it. >> >> If you want, at the Baltimore workshop, bring the LDs and, and I will bring >> them to Matt, in Pittsburgh. >> >> - Alex >> >>> On Sun, Jun 20, 2021 at 4:30 PM Jeffrey Brace via vcf-midatlantic < >>> vcf-midatlantic(a)lists.vcfed.org> wrote: >>> >>> On Sun, Jun 20, 2021 at 4:23 PM Jeff Salzman via vcf-midatlantic < >>> vcf-midatlantic(a)lists.vcfed.org> wrote: >>> >>>> I have a laserdisc player, time base corrector, and video capture card. >>> How >>>> soon does this need done? >>> >>> There is no rush for this, but I would like someone to work on it steadily >>> so that it doesn't get forgotten. >>> A player was donated, but don't know if it works or if it is better or >>> worse than your player. I will leave that up to you. >>> Alex Jaccocks has offered to do this, but maybe both of you can figure out >>> between you two who wants to do it or collaborate. >>> >>> >>>> >>>> Jeff Salzman >>>> >>>> On Sun, Jun 20, 2021, 3:23 PM Dean Notarnicola via vcf-midatlantic < >>>> vcf-midatlantic(a)lists.vcfed.org> wrote: >>>> >>>>> So called “Video Game Enhancers” are simple time-base correctors and >>> will >>>>> remove Macrovision. >>>>> >>>>> On Sun, Jun 20, 2021 at 3:07 PM Wil Birkmaier via vcf-midatlantic < >>>>> vcf-midatlantic(a)lists.vcfed.org> wrote: >>>>> >>>>>> Laserdisc has a few different formats: all analogue, analogue video >>>> with >>>>>> mono analogue audio and digital audio, or analogue video with all >>>> digital >>>>>> audio. >>>>>> >>>>>> They key to a good capture these days is to get the best composite >>>> video >>>>>> converter you can find as the video is stored like a vinyl record, as >>>> an >>>>>> analogue composite video stream. So yes using the svideo on some of >>> the >>>>>> newer players, the conversion of composite to svideo is still not the >>>>> best. >>>>>> I need to find a link to a decent converter to 720p I have been using >>>>> with >>>>>> vhs and am happy with. >>>>>> >>>>>> On Jun 20, 2021 14:45, Jeffrey Brace via vcf-midatlantic < >>>>>> vcf-midatlantic(a)lists.vcfed.org> wrote: >>>>>> >>>>>> Does anyone know if it is possible to transfer laserdisks to a modern >>>>>> digital format? There are 16 laserdisks recently donated that have C >>>>>> programming training from 1984, which was part of a UNIX and C >>>>>> training program. The reason for the transfer is that we don't know >>> how >>>>>> rare these disks are nor how long laserdisk will last. >>>>>> >>>>>> There are 16 laserdisks as well as supplemental floppy disks and some >>>>>> paper >>>>>> manuals. >>>>>> >>>>>> >>>>>> ========================================= >>>>>> Jeff Brace >>>>>> Vice President & Board Member >>>>>> Vintage Computer Festival East Show-runner >>>>>> Vintage Computer Federation is a 501c3 charity >>>>>> http://www.vcfed.org/ >>>>>> jeffrey(a)vcfed.org -- Dave McGuire, AK4HZ New Kensington, PA

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IBM and RCA computing video
by W2HX 22 Jun '21

22 Jun '21

After some telephone switchboard stuff, lots of shots of IBM and RCA computers in this pentagon data center video. https://www.youtube.com/watch?v=J8hLqpigv1g 73 Eugene W2HX

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Re: [vcf-midatlantic] Your selected charity received a $32.71 donation from AmazonSmile
by Dean Notarnicola 21 Jun '21

21 Jun '21

Thanks! I was only able to locate it on Amazon using the full string ‘Vintage Computer Federation’. This is the way it is listed on the IRS website. On Mon, Jun 21, 2021 at 10:40 AM Jonathan Sturges via vcf-midatlantic < vcf-midatlantic(a)lists.vcfed.org> wrote: > A quick note to anyone changing their Smile charity to VCF. I couldn't > get smile.amazon.com to locate VCF by any name-based searching I tried, > but using the tax ID # (47-4133714) works. > > -Jonathan > > >

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Re: [vcf-midatlantic] Your selected charity received a $32.71 donation from AmazonSmile
by Jonathan Sturges 21 Jun '21

21 Jun '21

A quick note to anyone changing their Smile charity to VCF. I couldn't get smile.amazon.com to locate VCF by any name-based searching I tried, but using the tax ID # (47-4133714) works. -Jonathan

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