Dual Goteks in the PC-8801mkIISR at last
Tags: computer nec pc88 pc8801mkiisr gotek floppy homemade-hardware mod
In my previous entry, I found out that my old IBM PC “DOS” floppy adapter was not sufficient when trying to read from two drives at once. Somehow, they confused the floppy controller enough that nothing could be read from the second drive.
Knowing that the PC-8801 speaks Shugart, and the Gotek speaks Shugart, the obvious next step was to get out of the way and allow the two of them to speak Shugart. As a result, I made a very simple edge-connector-to-IDC adapter.
When the boards arrived, I immediately soldered them up. And… nothing worked! The computer didn’t even seem to notice that it had floppy drives.
I spent two days on-and-off building nasty breadboard contraptions, reading up on the Shugart bus, and studying emulator source. Nothing made sense. The straight adapter should work perfectly.
Frustrated, I went back to the machine and compared the two adapters. I had put the IDC connector on the wrong side of the board, so that the signals were all backwards when I plugged it in.
After a quick re-solder job and tweaking the jumpers on the drives (both Goteks had to be set to S0), everything worked! Telenet Music Box (which requires both floppies inserted at the same time) launches immmediately. I now have dual Goteks in my SR.
With this change, the machine also doesn’t “hang up” for a long time at startup when there are no USB sticks inserted into the Goteks. Right into N88-BASIC, just like we like it.
So mark another one down for “total bonehead,” but also another successful board project. Now I just have to build two more adapters for the mkII so every PC88 in my collection can have a Gotek!