Adding RAM to the Epson IM-403
The IM-403 comes with a single empty 72-pin SIMM slot for RAM expansion. You can add any single- or dual-bank RAM strip to this slot. Just make sure you use the older, non-EDO RAM. If you put EDO RAM in this socket, your machine won't boot. (Want to guess how I know?)
When I was converting my IM-403 to a PC, I paid $25 for 16 megs of RAM. Not too long ago, that would have cost a couple of hundred bucks...
Refer to the IM-403 manual for details on adding the memory strip. The only problem you might run into involves single- versus dual-bank RAM. 72-pin SIMM strips with 1, 4, or 16 megs are generally single-bank, while strips with 2, 8, or 32 megs are dual-bank Install the SIMM strip per the manual, then power-up the box and see how much memory it reports. If you expect 16 and it shows 8, you need to jumper the box for dual-bank RAM.
The IM-403 isn't fussy about parity; it'll take either 32-bit or 36-bit strips just fine. If you install 36-bit (parity) SIMMs, you will need to use the System Configuration Utility on power-up to set up the unit for parity RAM.