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Thread: OSI reproduction boards: Who is interested?

  1. #1
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    Default OSI reproduction boards: Who is interested?

    Now that we have Gerbers from scans of several original OSI boards, we are able to produce some bare PCBs.

    We already have some actual PCBs out there, including Klyball's 600 and 610 boards, Grant's data separator board, Klyball's 470Z disk interface with data separator and RAM/ROM, plus Glitch's universal memory board and 560Z board. I think these are all available now, or will be soon.

    It looks like the cost will be on the order of $20-$25 per board if we get at least 10 PCBs in an order, not counting shipping. This is using the PCBcart online calculator for prototype boards. There may be better prices out there.


    I would like to use this thread to express interest in the following boards:

    502 (6502 CPU with 8K RAM and BASIC in ROM)
    505 (6502 CPU with floppy interface and extra I/O; no RAM )
    540B (color video board, 32 x 64)
    580 8-slot backplane

    These, together with the boards mentioned above, should be enough to create a full OSI system. For disk interfaces (if you don't have a 505 board) I would look into Grant's 470Z board. For memory, I'd look into Jonathan's new universal memory board before an older OSI board.

    I am considering doing a scan of the 48K dynamic RAM board and the 24K static RAM board, but the 24K RAM requires its own power supply in C2/C4 systems. it's got 48 2114 chips drawing 70 to 100 mA each. The lower end of that range is the low power 2114L chips!

    Use this thread, or the sister thread at the OSIWeb.org forum, to record your interest. If any board gets 10 interested folks, I'll pull the trigger. I'm counting myself as in for one of each board, so that makes 9 more hobbyists for any board.

    Dave

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    The Universal RAM board is just about ready for production, I need to add the C2P mounting hole and a few pull-up resistors to allow partial population.

    There are *plenty* of 560Z boards available, as well as full parts kits, including IM6100s.

    Happy to do the board orders and kits, or just the kits if you're wanting to run the boards, Dave.

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    As someone who doesn't know anything about OSI systems, what would it take to get a fully functional system built up from scratch? One of the two CPU boards, the video board, a backplane, and a memory board if the CPU board has no memory? Would you recommend a CPU board with no memory in favor of having the FDC built in? So at least 3 or 4 bare boards, plus all of the components to populate them, plus some sort of keyboard, power supplies, floppy drives?

    Seems like an interesting project, but I have no idea how much work and $ it would take to put a working system together.

  4. #4
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    I'd like to put my name down for a pair of 502 boards. Are these exact copies of the originals and therefore going to require a little extra work to use standard 2716 EPROMs?

    Cheers,
    Dave

  5. #5
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    Quote Originally Posted by Moonferret View Post
    I'd like to put my name down for a pair of 502 boards. Are these exact copies of the originals and therefore going to require a little extra work to use standard 2716 EPROMs?

    Cheers,
    Dave
    They are very close to the originals. Gerbers were prepared from calibrated scans of the original. That process replaced the original fonts with stroke fonts, and replicated polygons with numerous traces, resulting in slightly rounder edges. I imported the Gerbers into the Altium PCB program, recreated the polygons by tracing the outlines as closely as I could (to reduce the file size and processing time), and recreated the text to get closer to the original fonts. So, not exact.

    Now that the files are in Altium PCB format, a future project will be to enter the schematics and link the netlists. Then modifications will be a snap.

  6. #6
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    Quote Originally Posted by glitch View Post
    The Universal RAM board is just about ready for production, I need to add the C2P mounting hole and a few pull-up resistors to allow partial population.

    There are *plenty* of 560Z boards available, as well as full parts kits, including IM6100s.

    Happy to do the board orders and kits, or just the kits if you're wanting to run the boards, Dave.

    It would be awesome if you handled the PCBs.

  7. #7
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    Quote Originally Posted by dfnr2 View Post
    It would be awesome if you handled the PCBs.
    Yeah, no problem! Do you want me to put items in my preorder system for this? It's already set up, I'd just have to add the project(s).

  8. #8
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    That would be fantastic. Can you post here and on the osiweb forum, and indicate what the trigger will be for ordering?

    Thanks for taking this on!!

  9. #9
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    We also have gerbers for the 582 4-slot backplane, which my be of interest to anyone who would prefer a C4P style computer rather than a C8P big-box style.

    You can see the list of available reproduction boards on the Github site.

    Feel free to express interest in any other of the boards here as well.

    Dave

  10. #10
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    Quote Originally Posted by gslick View Post
    As someone who doesn't know anything about OSI systems, what would it take to get a fully functional system built up from scratch? One of the two CPU boards, the video board, a backplane, and a memory board if the CPU board has no memory? Would you recommend a CPU board with no memory in favor of having the FDC built in? So at least 3 or 4 bare boards, plus all of the components to populate them, plus some sort of keyboard, power supplies, floppy drives?
    You're right on target. If you want a BASIC-in-ROM and cassette model, like a C4P, then a 4-slot backplane, a 502 ROM/cassette CPU, and a 540B video board would get you started, and you could upgrade later to a floppy system by adding a 470 floppy board and a RAM board, or Klyball's 470Z which has the floppy and RAM all together.

    For a floppy system, the 505 CPU+floppy, a 540B video board, and a RAM board (from Glitch) would get you started. With the 505 board, you can add an A15 I/O connector board to get extra I/O. The A15 is also on Github, and if there is enough interest, I'm sure a run of those could be arranged.

    Seems like an interesting project, but I have no idea how much work and $ it would take to put a working system together.
    These designs are really meant to be built up and hacked by hobbyists, so there are lots of common TTL chips, widely spaced. That means lots of soldering, so a good soldering iron and good eyes (or good glasses.) I like to solder with a head magnifier nowadays.

    Each large 8x10 system board would be about $20 or so bare. I'm not sure how much parts would be but these boards have somewhere in the range of 10-30 TTL chips per board, and you'd probably want machined pin sockets, so parts could add up.

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