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Thread: PB-10 programmer schematics

  1. #1

    Default PB-10 programmer schematics

    Hi
    I see the post about someone trying to find information for the programmer they have. It is a shame that there isn't more information for these devices.
    I've had to repair my Needham PB-10 once. I realize that manufactures like to keep their schematics private but the Needham PB-10 is now, way, obsolete and no longer manufactured. No one is interested in building one today, especially with the number of cheap programmers available from China right now. I just want to be able to fix the one I have when I need to use it. I had to do a lot of signal tracing and note taking to figure the various parts out. There were even some tricky things done to the circuit to make is difficult to easily copy the hardware. Part of the lower address bits were done with a counter chip and they'd swapped a couple of the address lines, just to make it annoying. I hardly think that would stop a serious attack. It just makes it a little more trouble.
    I've made a number of routines to set the various pins to values so I can look to see if anything is running slow with a scope. I did this in Forth but one could easily convert it to some other language. It is not a schematic, just what the signals do. If anyone is interested I can post this information.
    Dwight

  2. #2
    Join Date
    Jul 2014
    Location
    New Hampshire, USA
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    I’m pretty sure that Needham did release the schematic for the PB10. They were a great company to deal with, but sadly no longer in business (the current owners have the name but don’t really support any of the original products).

    I can see if I still have a schematic at home. At the very least my PB10’s were socketed so repair should be pretty straight-forward. If all else fails I believe I have spare boards and rarely use the BP10.

    - Gary

  3. #3

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    I would love to have a schematic. I don't need to repair it now. It seems to work fine. It had one of the open collector buffers fail. I've long since replaces that part.
    Dwight

  4. #4
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    Jul 2014
    Location
    New Hampshire, USA
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    I found a print-out of the schematic. The original file might be on one of the 5.25" disks but I'll have to pull out an older system to look.

    I scanned the printout to http://www.the-planet.org/PB-10_Schematic.pdf

    Not perfect, but should be good enough for repair.

    The only failures I've ever had were in the 7407's or the cable. I also have the micro adapter board here somewhere...

    Enjoy!

    - Gary

    Quote Originally Posted by Dwight Elvey View Post
    I would love to have a schematic. I don't need to repair it now. It seems to work fine. It had one of the open collector buffers fail. I've long since replaces that part.
    Dwight

  5. #5

    Default

    Quote Originally Posted by gekaufman View Post
    I found a print-out of the schematic. The original file might be on one of the 5.25" disks but I'll have to pull out an older system to look.

    I scanned the printout to http://www.the-planet.org/PB-10_Schematic.pdf

    Not perfect, but should be good enough for repair.

    The only failures I've ever had were in the 7407's or the cable. I also have the micro adapter board here somewhere...

    Enjoy!

    - Gary
    Yep, same 7407, open collector buffer. The PDF looks fine. Thanks.
    One other question, you wouldn't happen to have a 8748 adapter would you? If I had a schematic I could make one.
    Dwight

  6. #6
    Join Date
    Jul 2014
    Location
    New Hampshire, USA
    Posts
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    Dwight -

    I do have an 8748 adapter, but no schematic. I think I have a spare, but couldn't easily locate it last night. I'll keep looking, if I do have a spare I certainly don't need two.

    I found the original PB-10 schematic file on floppy, but it's a .PRN file I'm guessing it's formatted for some "standard" dot matrix format, perhaps Epson. If it's of interest I could pass it along.

    Quote Originally Posted by Dwight Elvey View Post
    Yep, same 7407, open collector buffer. The PDF looks fine. Thanks.
    One other question, you wouldn't happen to have a 8748 adapter would you? If I had a schematic I could make one.
    Dwight

  7. #7

    Default

    The adapters were not overly complicated for these as I recall. If you don't find the extra, it shouldn't be too much to trace out the leads.
    I have the adapter for the 8751s but have always wanted one for the 48 series parts.
    Dwight
    Last edited by Dwight Elvey; June 6th, 2019 at 09:48 AM.

  8. #8
    Join Date
    Jul 2014
    Location
    New Hampshire, USA
    Posts
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    I located my spare PB10 87xx adapter board, a picture is attached.

    This board supported 8751's, 7742's, 8748's, 8755's etc. I believe it was a later design than the single 8751 adapter you have.

    You're welcome to borrow it for copying - or I'd be happy to trade it.

    = Gary

    Quote Originally Posted by Dwight Elvey View Post
    The adapters were not overly complicated for these as I recall. If you don't find the extra, it shouldn't be too much to trace out the leads.
    I have the adapter for the 8751s but have always wanted one for the 48 series parts.
    Dwight
    87xx Adapter.jpg

  9. #9

    Default

    Quote Originally Posted by gekaufman View Post
    I located my spare PB10 87xx adapter board, a picture is attached.

    This board supported 8751's, 7742's, 8748's, 8755's etc. I believe it was a later design than the single 8751 adapter you have.

    You're welcome to borrow it for copying - or I'd be happy to trade it.

    = Gary

    87xx Adapter.jpg
    I'd love to track it out and make a schematic. It needs a different zif and cable to go to the 87xx part. From the schematic I should be able to determine what that would look like. I do have the 8751 adapter. The 8755 is programmed differently than the 8755A. I'd need to look into that if I ever wanted to do a 8755A. We can move to email. You have the right one.
    Dwight

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