!pr2
Fixing the Andromeda 16K Card.....................Bob Bernard

In the April 1984 Call-APPLE there was a letter from John Wallace regarding a problem with the Andromeda 16K RAM card.  As this card was the second on the market, first after Apple's (which was bundled with Pascal), there are probably still tens of thousands in use.  Yet the Andromeda is anathema to some hardware and software.

In particular, it played havoc with John Wallace's copy of Apple PIE (a popular word processor from yesteryear), and my Lobo 8" floppy drive controller (another relic, I suppose).  Bob S-C tells of running into the problem too:

!lm+5
!rm-5
"I have an Andromeda board, and I ran into this problem with early versions of ES-CAPE.  Using a STA (or other store) opcode to any soft switches on the Andromeda card write-protected the card.  Using two stores in a row to try to write-enable the card does no good either.  I had to change all stores to loads or BITs to make it work.  Apple's board accepts either stores or loads, as do all other memory cards I have tested."
!lm-5
!rm+5

There are probably lots of interfaces and programs out there which stumble over Andromeda.  Wallace details a hardware modification to the Andromeda board which makes it work the same as all other memory boards.  I found a slightly simpler way, and I recommend that all Andromeda owners fix their boards as soon as possible.

Remove the 74LS08 chip at board location U13.  Bend pin 10 out so that it sticks straight out, and plug the chip back into its socket so that pin 10 is on the outside.  Solder a small wire to pin 10 (carefully), and solder the other end of the wire to pin 14 of the same chip.  Or, you can solder to a solder pad pin 14 is connected to, as shown in the drawing below.  (Pin 14 is connected to Vcc, the +5 volts line.)  That's all there is to it.

John Wallace suggests using a 1K resistor rather than a wire, but I found a wire is sufficient.

With the wire installed, both reads and writes can be used to switch the card, just like Apple intended it.
