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Thread: National Semiconductor SC/MP Low Cost Development System Manual Needed

  1. #11
    Join Date
    Feb 2014
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    Melbourne, Australia
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    Welcome here,

    good you got the help from Museum Vic.

    What part of Melb are you in?

    Eastern side of bay or western side?

  2. #12

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    Hi Everybody,

    Sorry I haven't been keeping up with this thread.

    Museum Victoria also sent me a PDF of the manual - very nice to have! They must have been very surprised at the sudden burst of interest!!

    If anyone wants me to check something out on my working system just let me know!
    I did dump the ROMs but it sounds like folks have access to listings etc.

    Geoff

  3. #13

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    Quote Originally Posted by GeoffC View Post
    Hi Everybody,

    <snip>

    I did dump the ROMs but it sounds like folks have access to listings etc.

    Geoff
    And after way to long I've uploaded them to github:

    https://github.com/geoffcoward/retro...ster/scmp-lcds

    If anyone needs these in another form or anything like that please let me know.

    I'm necro'ing this thread just so it's all in one place.

    Geoff

  4. #14
    Join Date
    Jan 2020
    Location
    South of England
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    I spoke with a friend who built a SC-MP system about manuals, he mentioned some manuals are at: http://www.bitsavers.org/components/national/scmp/
    Do these help?

    Chris

  5. #15
    Join Date
    Jan 2015
    Location
    Sydney, Australia
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    Hi,

    Unfortunately the actual SC/MP LCDS Manual isn't in the Bitsavers repository.

    I am currently restoring an LCDS, but it fortunately has all the manuals. I was able to read the ROMs using my homebrew 8085 system, but one of the ROMs is dead. I hand typed the LCDS listing and ran it through my 2650 x-assembler, and then cross checked it to ensure the x-assembler output perfectly matched the LCDS listing. I burnt it to a 2716 EPROM and connected it up via the standard LCDS bus, but it didn't work. Maybe it needs to be burnt into 4 x 2716 EPROMS, using only 512bytes of each ROM and connected to the signals that connected the original ROMs. So, I will give that a try when I get a chance.

  6. #16
    Join Date
    Sep 2006
    Location
    Silicon Valley
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    Quote Originally Posted by river View Post
    Hi,

    Unfortunately the actual SC/MP LCDS Manual isn't in the Bitsavers repository.

    I am currently restoring an LCDS, but it fortunately has all the manuals.
    do you have a way to make a copy of the manuals, or scan them?
    I know someone who has a partial LCDS and would like to put together the missing pieces

  7. #17
    Join Date
    Jun 2012
    Location
    UK - Worcester
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    Yes, it would be really useful to get a copy of this manual on bitsavers.

    Dave

  8. #18

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    Hi,

    I just sent a copy of the manual to bitsavers.

    Geoff

  9. #19

  10. #20

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    Quote Originally Posted by river View Post
    Maybe it needs to be burnt into 4 x 2716 EPROMS, using only 512bytes of each ROM and connected to the signals that connected the original ROMs.
    So, I will give that a try when I get a chance.
    If you are saying that the PROM code was originally programmed into multiple PROM devices (of which one failed) then you should be able to use a single EPROM programmed only with the code that PROM originally contained to substitute for that device.

    Just make sure the /CE signal on the PROM's socket is connected to both the /CE ( pin 18 ) and /OE ( pin 20 ) pins of the substitute EPROM, and make sure all unused lines of the EPROM, especially the upper address lines, are tied to an appropriate state (So if the original PROM only has A0-A8, say, tie A9, A10 on the 2716 EPROM to 0V).

    If the original PROM is 4-bit wide, then obviously only connect D0-D3 of the 2716 to the corresponding pins on the socket.

    Also, VPP (pin 21) on a 2716 needs to be held at +5V in read mode.

    When doing this kind of thing I usually take a surplus ordinary (not turned pin) socket which will fit into the socket for the PROM and then solder wires to the contacts of the surplus socket. These wires I then take to the corresponding pins of a larger socket which is the right size for the EPROM which will be standing in for the PROM.

    Attached, an example of this sort of adaptor lashed up to make a standard 8-bit wide EEPROM look like two 4-bit wide bipolar PROMs. The image clearly shows that the makeshift 'headers' for plugging into the 16-pin PROM sockets are just IC sockets with wires soldered to them. I use ordinary sockets rather than turned-pin because their flat pins fit more snugly into existing conventional sockets than the round pins of turned-pin sockets do.
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