5 comments on “Memory upgrade on gerontological HP printers

  1. Pingback: » Making Standard SIMM s Work / Memory Upgrade on the HP LaserJet 6MP / 5MP - Dennis Little: Eclectic Commentary on Business and Technology

  2. This is an excellent blog post and you did a better job explaining presence detect thatnI ever did. I have linked back to here on the HP SIMMs post on KeyCruncher.com. Thanks, Dennis (aka KeyCruncher)

  3. Can’t thank you enough. I bought a cheaper 16MB stick and it didn’t work. the HP sticks were $5 more. All I had to do was solder a little wire for 0101 instead of 0001. Going to order 2 more now.

  4. Hello,
    I’m trying to follow your tutorial to add memory to an HP LaserJet 5P. I have two memory SIMMs, but not sure what sizes they are.
    1) two-sided module, has 8 x TC514256AJ-80 chips and 8xTC5126T-80 JAPAN 9028HAK chips, not sure what the size is. PIN 70 is connected, so that would make it a 0001, is that correct? Seems like it is an 80ns module
    2) one-sided module, 8xPanasonic MN414400CSJ-07 9543TAA30 chips, size seems to be 4MB. No PINs are connected to 72, that would make it a 0000, is that correct?

    I don’t understand how you added a wire to change from 1101 to 1001, I imagined you needed to take a connector out, not add one?
    Can you detail this a bit more, maybe in the main article?

    To me, it seems you originally had 67-off, 68-connected, 69-off(you connected it afterwards), 70-off. How does that translate to 1101 or 1001 ??
    Thanks!

    • I am really trying to remember the magic. The most probable explanation is that I started from the code 1101 (..X.) “X means connected to ground” and only one via installed) and I finished at code 1001 (.XX.) which means two middle vias installed. Yes, the source at http://ps-2.kev009.com/eprmhtml/eprma/h871.htm uses negative logic: X’s to indicate the vias and .’s for the omission.

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