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Thread: Saving ROM data from Tek 4052

  1. #101

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    Whoa... did I just get promoted to senior member??
    "END OF LINE" [MCP, 1982]
    "An admin that isn't a bit hackerish is just the guy mopping up the keyboard" [Phrack V0b I3f P12]
    "Any appearance of danger is simply a device to enhance your experience" [Futureworld, 1976]

  2. #102

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    So, spend the day rummaging through my pile of 4052 PCB's.
    Result : 5 dead 4116's ( out of ca 120 tested ), the diagnostic rom pack really helps here.
    I now have 3 sets of confirmed working 4052 (digital-) PCB sets. My remaining PCB's will be tested another day.
    My second 4052 will still need some fixes in the analog department and in the powersupply.

    Roland, if you want to borrow a set of boards and / or the debugger over the festive season, be my guest !

    Jos

  3. #103

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    Hi Jos,

    4% failure rate... could be worse tho.
    Is there a pattern regarding date / manufacturer label?

    Many thanks for your generous offer, I could actually use the time to try out the debugger / diagnostics! That said, I probably won't be passing by Koblenz anytime soon. I will check if I have an opportunity before Xmas. Not exactly sure when I'll be taking my break, yet.

    Meanwhile, I'll have another look at those schematix you uploaded. I exposed and etched a board aeons ago, in the early 90s, but since never took an another project that needed it.

    --Roland
    "END OF LINE" [MCP, 1982]
    "An admin that isn't a bit hackerish is just the guy mopping up the keyboard" [Phrack V0b I3f P12]
    "Any appearance of danger is simply a device to enhance your experience" [Futureworld, 1976]

  4. #104

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    Quote Originally Posted by GanjaTron View Post
    4% failure rate... could be worse tho.

    --Roland
    4% may not seem bad, but with 36 4116's in the system the likelihood of at least one being bad is 77%...
    Start looking into those ram's !

    Jos

  5. #105

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    I've just gone through the Diagnostic ROMpack manual, and it does indeed mention a microcode memory test in the appendix. It mentions that if RAM near the bottom of memory is bad, the diagnostics module may itself hang. In this case the on-board microcode test can help identify the faulty chips via the program counter:

    The program counter on the MCP board contains a mask that indicates which bits [chips] are bad ... Any bit that is logic 1 indicates an error. This method isolates the error to two RAM chips. It cannot determine which is the bad chip because the order in which the two bytes were fetched is not known.
    So either my microcode detected over a dozen faulty chip pairs, or the PC indicates actual firmware running, and doing exactly what we would expect it to do with a loop coded in the firmware. I think I'll go with the latter...

    I also took a look at the diagnostics module schematic. Most parts should be straightforward to get, and the two 2716s can be replaced with a more common 2732 or 2764. But what's the modern equivalent of the 6810 static RAM (128 x ? I also noticed there's no photo of the PCB itself, which would serve as a basis for a layout template. Having said that, it shouldn't be all that difficult to breadboard this thing.
    "END OF LINE" [MCP, 1982]
    "An admin that isn't a bit hackerish is just the guy mopping up the keyboard" [Phrack V0b I3f P12]
    "Any appearance of danger is simply a device to enhance your experience" [Futureworld, 1976]

  6. #106

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    Quote Originally Posted by GanjaTron View Post
    I
    But what's the modern equivalent of the 6810 static RAM (128 x ?
    I also noticed there's no photo of the PCB itself
    I would go for a 6116 sram to substitute the 6810, picture of front and backside of the PCB are on my FTP site.

    Still contemplating to make a PCB with Kicad, but interest is very limited, and it would also have to be usable as a normal ROMPACK.


    Jos

  7. #107

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    Quote Originally Posted by jdreesen View Post
    I would go for a 6116 sram to substitute the 6810, picture of front and backside of the PCB are on my FTP site.

    Still contemplating to make a PCB with Kicad, but interest is very limited, and it would also have to be usable as a normal ROMPACK.


    Jos
    Hi Jos,

    sorry, those photos on your FTP site aren't accessible -- please check the permissions. Making a PCB in the ROMpack form factor might be a bit of a challenge. Alternatively, we could go for a 50-pin edge connector with ribbon cable that connects to J5 after removing the ROMpack slot assembly. A bit cumbersome, but maybe easier to source the parts.

    --Roland
    "END OF LINE" [MCP, 1982]
    "An admin that isn't a bit hackerish is just the guy mopping up the keyboard" [Phrack V0b I3f P12]
    "Any appearance of danger is simply a device to enhance your experience" [Futureworld, 1976]

  8. #108

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    Hi everyone,

    I checked out some prototype boards with 44pin edge connectors last night, and came across Vector Electronics' "Plugbord":
    https://www.vectorelect.com/plugbord...-contacts.html

    Digikey and Farnell stock them, though they're not cheap. Still they'd be an alternative starting point for a homemade diagnostics module if we don't go the KiCAD route. Having said that, I'll try to contact posters in the other 4052 threads on here, who have similar issues with their units.

    --Roland
    "END OF LINE" [MCP, 1982]
    "An admin that isn't a bit hackerish is just the guy mopping up the keyboard" [Phrack V0b I3f P12]
    "Any appearance of danger is simply a device to enhance your experience" [Futureworld, 1976]

  9. #109

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    Hi Roland,

    the prototype boards you link to are not suitable, as they have the wrong spacing on the edgeconnector. ( 0.156", should be 0.100" ) You will shortciruit the signals / power supply etc.
    If we have 10 or so interested people then a PCB order in China will be cheaper than buying prototype boards. And much more reliable.
    But I have had only 3 reactions so far, and that is yours included...

    Jos

  10. #110

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    Quote Originally Posted by jdreesen View Post
    the prototype boards you link to are not suitable, as they have the wrong spacing on the edgeconnector. ( 0.156", should be 0.100" ) You will shortciruit the signals / power supply etc.
    Hi Jos,

    thanks for pointing that out; I didn't even notice that, nor do I currently have a module at hand to check the edge connector spacing. Vector has only one 44pin plugboard with 0.1" spacing (https://www.vectorelect.com/3795-1.html), but I haven't found any retailer who stocks it, and it's too small to accommodate the diagnostix module components.

    --Roland
    "END OF LINE" [MCP, 1982]
    "An admin that isn't a bit hackerish is just the guy mopping up the keyboard" [Phrack V0b I3f P12]
    "Any appearance of danger is simply a device to enhance your experience" [Futureworld, 1976]

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