Upgrade RC2014Mini to run CP/M2.2


This is a step-by-step guide for upgrading a RC2014 Mini so it can run CP/M 2.2.



Materials required

The following are needed to perform the upgrade:

  • 28-pin 600-mil wide socket
  • 128Kx8 RAM, AS6C1008, TC551001, or KM681000
  • MCP130-460DI voltage supervisor
  • W27C512 EEPROM
  • 14.7456MHz full-size oscillator
  • Compact Flash board I/O address strapped to 0x10 to 0x17

64K RAM Upgrade

Remove the 32K RAM, AS6C62256 from its socket. The upgraded RAM is a 128Kx8 RAM such as AS6C1008, TC551001, or KM681000) which is a 32-pin device. The 32-pin device is larger than the existing space can accommodate so it needs to be mounted on a 28-pin socket that, in turn, plugs into the existing 28-pin socket so the extra 4 pins hang over the socket and above the Z80 CPU. The following is modification to the 128Kx8 RAM and its socket:

  • Connect pin 2 of 128Kx8 RAM to pin32 of RAM,
  • Connect pin 32 of RAM to pin 30 of the socket
  • Cut off the skinny leg portion of pin 22 and straighten out the remaining lead so it won't touch the socket; connect a wire from the remaining lead to ground (pin 16) of RAM.
  • Connect pin 22 of the socket to pin 31 of RAM
  • Cut off the skinny leg portion of pin 30 and straighten out the remaining lead so it won't touch the socket; connect a wire to the remaining lead and leave it unconnected for now.


  • Insert the RAM along with its socket in the original 28-pin RAM socket. Pin 1,2, 31,32 of the RAM should hang over the Z80 CPU
  • Thread the uncommitted wire (connected to pin 30 of RAM) through the center hole of the RC2014Mini pc board to the solder side; connect to pin 11 of U1



16K ROM Upgrade

Add ROM-to-RAM paging circuit

CPU Clock Upgrade

CF Card


MiniMon, Simple monitor for RC2014 Mini

CP/M2.2, CPM BDOS/CCP/BIOS for MiniMon


MiniMon operating guide

Installing CP/M in a new CF disk

builderpages/plasmo/rc2014miniupgrade.txt · Last modified: 2019/06/19 08:47 by plasmo
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