I have the PC85 Microbee from the last post working now. Thanks to Ernest, who persevered in his assistance and identified a mistake in the ROM order, I was finally able to get a proper booting PC85B system. This allows double sized (16K – AKA 27128) ROMs and I’ve got a couple of additional games installed in “high” ROM spots above existing ROMs.
(The PC85 “core” (or top) board is the same between the A and B variants* so it’s a simple ROM swap to upgrade from one to the other)
From here on out, I’ll probably swap out the ROM that currently contains Viatel, as I have no use for that, and swap it for some additional games.
I am also beginning my research on how to make a clear acrylic case for this unit. I figure a nice transparent case will show off the beautiful innards of this system, and it is beautiful.
For anyone who is upgrading the PC85 from A to B, the ROMs need to go in the following sockets:
|ROM Name||IC Socket N°||Lower ROM PAK||Upper ROM PAK|
|ROM E||IC 25||PAK1 (Help)||PAK9 (Free)|
|ROM F||IC 24||PAK2 (Spreadsheet)||Reserved|
|ROM G||IC 23||PAK3 (Graphics)||Reserved|
|ROM H||IC 22||PAK4 (Viatel)||PAK12 (Free)|
|ROM I||IC 27||PAK5 (Shell/Menu)||PAK13 (Free)|
*Just to be especially exciting, there’s a MB8328-2 model that could theoretically be in a PC85 that needs a mod to be upgraded to 16k ROMs. Thankfully mine is a MB8328-4 which doesn’t have this disadvantage