128K system ROM socket adapter for Olivetti Prodest PC128s or Acorn BBC Master Compact
This is a DIP28 adapter PCB to place two 27512 EPROMs instead of a single 27C010
This socket adapter is intended for who wants to have 128k of memory in the system ROM instead of the 64K the PC comes with.
Follow the instructions on how to correctly program the two 27512 EPROMs at https://oshwlab.com/black__man/acorn-bbc-master-compact-128k-system-rom
Warnings:
- Put the jumper PL12 on south position otherwise the socket adapter won't work
- The original system ROM the PC comes with can't be just put on the system socket ROM of my adapter unless reprogrammed
- Program the two 27512 ROMs with the correct layout otherwise the PC won't boot at all
- The adapter is shipped with no ROMs on it. It should work with every 27512 compatible EPROM
- If using my adapter, no ROMs can be put on socket IC38