ZiLOG Z80-RIO Operating System User's Manual page 39

3.4.5 PCON
The PROM console driver provides basic console I/O and
becomes the default device for logical units I and 2
when OS encounters errors while requesting input from
or output to these units. Refer to the MCZ or ZDS PROM
User's Manual for full details.
3.4.6 FLOPPY
The PROM floppy disk driver is used by ZOOS as the access
primitive for the floppy disk drives. Refer to the MCZ
or ZDS PROM User's Manual for full details.
3.4.7 DISK
DISK is the hard disk controller interface provided for
those utilities requiring access by sector address. Refer
to Chapter 7 for full details.
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