Date   : Sat, 09 Jul 1988 19:52:29 GMT
From   : eve.usc.edu!mlinar@oberon.usc.edu (Mitch Mlinar)
Subject: CBIOS & format for Xerox 820-1 w/double dens mod

In article <8480@pur-ee.UUCP> young@pur-ee.UUCP (Mike Young) writes:
>   I have a Xerox 820-1 I'm trying to upgrade to double
>density, using the WD 2793 controller (yes, and the Emerald Microware
>upgrade kit). It runs CP/M 2.2, and does it very nicely. It occurs 
>to me that I will need a format program to handle
>double density. I could write one, but if someone else has invented this
>particular wheel, why should I? :-)
>
>   In addition, the CBIOS will also need to know how to select the
>proper density, keep track of who's double and who's single at any given
>moment, etc. (this particular system will have 2 to 4  5 1/4" DSDD drives


There are a couple of ROMs sold for the 820-I which have a number of
utilities associated with them.  One is the Xpro MicroCornucopia ROM and the
other is the MicroCode Plus2 ROM.  The Xpro is super-cheap since it has few
features in it.  Plus2 is about $40(?) but has about 11 formats built-in, a
way to define user-definable formats, and can read/write MS-DOS disks through
Bridger Mitchell's DosDisk program.  There are a bunch of other features
Plus2 has that Xpro does not; Xpro only comes with ROM, BIOS, FORMAT, and
SYSGEN.

I will have to warn you that I am a tad biased, though, since I wrote the ROM
and all utilities for it.

-Mitch