Great pictures! I also noticed your 72pin SIMM trapdoor expansion. May I ask if your trapdoor expansion works to 1Meg? The reason I ask is that I was considering soldering a 72pin direct to the trapdoor expansion of my a600 but I found that the 72pin SIMMS did not have the /OE line - because of this I desoldered a 4MB DRAM chip from a 72pin SIMM (the individual DRAM has the OE line) and soldered (what I thought from the schematics) MA9 on the trapdoor to only realise that the schematic diagrams for the A600 are wrong and address line 9 is not connected at the trapdoor slot (expansion connector pin 32 )so I only got 0.5MB of extra ram since the DRAM chip only has one RAS line..... so if the /OE line is not needed on the 72pin SIMM then I can solder a 72pin simm directly to the trapdoor slot expansion and wire the RA0/RA1 lines to the correct points on the SIMM... does this make sense to you or if not do you have details of your SIMM->TRAPDOOR expansion as shown in your released picture? Many thanks, Paul.
