<common-ish machines that _can_ do the formatting. 8" 'RX01' floppies can <be formatted in most soft-sector 8" CP/M machines (and a PERQ will not <only do the format, it'll even stick an 'RT11' directory on the disk). Or if the cpm machine is running the RT11 package (a C program) it could set a directory and read/write the disk as well! Still use that one here! <You say 'some Rainbows'. I thought this was just a software <consideration, and that the hardware of all 'bows was capable of <formatting blank disks. Since the 'bow disk controller is just a WD179x <chip (IIRC) on one of the micro's buses, it seems hard to figure out a <way to stop it from formatting, although anything is possible. The rainbow needed a formatter program to do it. It was generally available. However DEC used the 1793 in a lot of systems (DECMATE, PRO3xx, and a few other but hid it behind a 8051 microcontroller that didn't have a format routine in the internal rom. Reason, the 1793 needs to be fed every byte to write to the disk including gaps and marks. DEC hardware that can format floppies: Vt180 RX180 format. PDT-11/150 RX01 format Rainbows (RX50) RQDXn (in either a Qbus MicroVAX or PDP-11) with software (rx50, rx33, Rx23, rx24, and hard disks) VS2000 (rx50, rx33, hard disks) RX02 can reformat from RX01 (SSSD to SSDD and back). It just cant do the initial format. There maybe other but those are most common. Of the non DEC hardware that can do 8" formatting CCS2xxx systems (S100/cpm) (both 8 and 5.25) Compupro S100 (various cpus) (both 8 and 5.25) SDS " " Teltek " " Multibus with nonINTEL DD controllers (NEC BP2190 8", 5.25 or 3.5) Xerox820 SB180 (8, 5.25, 3.5) Ampro (8"SD, 5.25, 3.5) and the list goes on..... Allison