Introduction

I have a number of older Japanese computers. This board was originally developed so that I could use a Gotek floppy emulator on my NEC PC-8801mkII, which only accepted 5.25" floppy drives with an edge connector. As with all of my boards, it has gone through a bunch of revisions (and been installed in a lot of computers) since the original development.

The original version of this adapter was actually the second PCB I ever made, back in 2018.

You can read more about my development of this board through the following articles on my blog:

• PC-8801mkII floppy adapter board
• Revenge of the PC-8801mkII floppy adapter board
• Attempting dual Goteks in the PC-8801mkIISR
• Dual Goteks in the PC-8801mkIISR at last
• ...the X1 turbo article is still coming!

Fabrication

Although it's not essential for correct function, opting for hard gold plating and a bevel on the edge connector will make sure that this adapter will last through many insertions and not corrode.

Compatibility

This adapter has been tested on the following computers:

• NEC PC-8801mkII
• NEC PC-8801mkIISR
• Sharp X1 turbo
• Sharp X1 twin

Please let me know what computers you get it to work on!

Assembly

Once you have the 34-pin right-angle female IDC connector, solder it so that the plastic part of the connector is on the side of the board marked "mount connector this side."

Then, attach the adapter to the back of your 34-pin 3.5" floppy drive, and slot the edge-connector side into your floppy cable.