Got this idea from Ben Weaver’s website after he had already hacked up a QS6. You can read about all the motivations behind this fix there:
The mention on the website was that someone tried on a QSR and it did not work. Well, I proved the opposite. It works quite well, although my implementation puts the address switches on the back of the unit. Micro switches on the front would probably work better, but I digress. Onward.
Starting from the pinout of a PCMCIA card, we’ll need A23 (16MB) and A24 (32MB) for larger card support.
QSR schematic not available, but used QS6 as reference. A23 (Pin 122) and A24 (Pin 123) need to be cut.
Zoomed out to show the A23 switch addition – purple wire.
Close up of connections. A23 only at this point. Note the cut traces for both A23 and A24.
PCMCIA numbering is odd – numbers counted in zigzag. Bottom card (1-68) and top card (69-136). Shown for reference.
Added second switch for A24, and reusing power and ground for that switch as well.
Drilled holes in back where there was room for switches.
Now once you get everything modded, you need to get a card programmed with the data. That I will leave for another post!