Apple IIgs (rom 0)
 
Apple IIgs (rom 0)
I've bought also an early original rom (00) IIgs. However i've replaced its motherboard with a fully functional rom 3 motherboard because of rom 0 lacking compatibility with GSOS and IIgs software developed since 1988. Rom 0 and 1 have the same motherboard: they differ because of updated DIP 28 128 kb EPROM data, and updated VGC (video graphic control) wich was responsible of occasional purple fringing during old apple II graphic modes emulation.
Original box
Rom 1 and rom 0 apple IIgs. They have identical motherboard: only an out of date 28 pin DIP EPROM, and a faulty VGC.
A rare precious fully original ROM 0 motherboard.
342 0077-A is the code of 28 pin DIP "rom 0" EPROM (instead of 342 0077-B peculiar of rom 1). Interesting Microsoft 1977 Applesoft basic copyright :)