Shugart-Interface 8" Floppy Diskette Drive Configurability

Mark J. Blair nf6x at
Sat Sep 7 10:05:09 CDT 2019

I've been contemplating a floppy diskette drive emulator with features to make it fit better into systems using 50-pin Shugart style floppy drive interfaces vs. the other emulators already on the market. Studying manuals for various 8" floppy diskette drives, I see that they generally provided a great deal of configurability. There are the myriad of jumper-selectable options which change drive behavior for compatibility with various computers. Then there are features like FM data separators which are present on some, but not all, drives. And then there are many documented "cut this trace, then bodge wire this signal to pin X of the edge connector" options for special purposes such as individual drive motor controls, simultaneous monitoring of all four drive ready signals, etc.

Since fully supporting all of the options I've seen documented would have real hardware cost and add complexity to the design, I'm wondering just how much of that configurability is really necessary. Which non-default options are really needed for system still in use and/or in the hands of collectors? Which were only ever provided for some obscure industrial system manufacturer, with no surviving systems in existence? Which were included just in case somebody might need them, but were never used in practice?

I'd appreciate it if anybody can provide insight into this, such as examples of systems which required non-omnipresent and/or non-default configuration options.

Mark J. Blair, NF6X <nf6x at>

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