Space, the next frontier - test-drb@ccmp.vtda.org

25 May 1999

...
 > Q-bus or Unibus controller.  (On some Rainbows, it
is possible to low-level
> format RX50 media directly.) 
...
 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. 
On a Rainbow, a dedicated Z80 does the floppy I/O; the formatting
code has to be in the Z80's firmware (which, indeed, is a "software
consideration".).  In some revisions of the Z80's firmware,
the format option for RX50's isn't present (it returns an error).

I'm currently looking for the "RX50 FAQ", put together by Charles
Lasner most of a decade ago, in hope that it discusses which firmware
revisions are/aren't capable of formatting.  So far I've turned up
about 30 pages of Charles's notes on RX50 interleave issues, but
nothing about the Rainbow firmware!

-- 
 Tim Shoppa                        Email: shoppa(a)trailing-edge.com
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