In order to be able to use any IBM compatible DSDD 5-1/4 disk drive with the "mount" command, a special latching and recognition circuit is necessary. The schematic enclosed is drawn with DPaint in hi res with 1 bit plane. The 23 pin connector plugs into the back of df1:. As you are probably aware, this is a difficult to get connector. However, a 25 pin connector can be cut down to fit. Just remember to renumber pins 13-23 appropriately. The 34 pin connector is a standard card edge connector universally used to interface with 5-1/4 inch drives.
Be sure the drive you use has the drive # select jumper in the drive 0 (the lowest number available) position, as the Amiga does the selecting, assuming all drives are number 0. Pins #9,20, and 21 are the drive select lines, and are rotated in the Amiga boxes, so that line 21 out of Amy selects df1:, and line 21 out of df1: selects df2:. Actually, out of Amy, line 21 selects df1:, line 9 selects df2: and line 20 selects df3:. All on the 23 pin connector, of course.
In addition to the circuit depicted, you will need a 12 volt and 5 volt power supply appropriate to the disk drive. The last I looked, Radio Shack had two different combined supplies priced at around $5.
Any construction technique should work. Mine is wire wrapped, but worked well on a breadboard as well. Don't forget RF shielding if you or your neighbors have trouble. This is probably not a beginner project since an improperly wired connector could damage the Amiga, or the 5-1/4 drive. Anyone with a little experience should have no difficulty, however.
This circuitry works with Transformer, as well, if you can get a dealer to sell it to you cheaply without the bundled drive.
