Cambridge Computer patents related to Z88 :
Issue 4 board modification to use a full internal slot with 512K static RAM and a 512K 5V Flash Eprom. An internal Flash Eprom allows OS update with ROMUpdate Utility.
View of the full internal slot with a 512K Flash Eprom on the left (Am29F040) and a 512K SRAM (HM628512) on the right.
Component side tracks to be cut near the ROM socket which has to be added after unsoldering of the old ROM.
Tracks to be cut and wires to be added on the PCB side.