The Zilog MCZ is an extremely early Z80 development system, produced by Zilog, which came out in 1976. It used twin 8-inch hard sectored floppy drives; here’s one at the Centre for Computing History:

A Zilog MCZ at the Centre For Computing History

The MCZ ran Zilog’s own operating system, Z80-RIO, and used 77 track single-sided disks, with 32 sectors (each marked by an index hole), with 132 bytes per sector — 128 bytes of user payload plus two two-byte metadata words used to construct linked lists of sectors for storing files. These stored 320kB each.

FluxEngine has experimental read support for these disks, based on a single Catweasel flux file I’ve been able to obtain, which only contained 70 tracks. I haven’t been able to try this for real. If anyone has any of these disks, an 8-inch drive, a FluxEngine and the appropriate adapter, please get in touch

Reading discs

Just do:


You should end up with an zilogmcz.img which is 315392 bytes long.

Useful references

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