On Thu, Mar 06, 2008 at 04:13:01PM -0300, Alexandre Souza wrote:
>IDE interface wants to be 16 bits, and given that
the bus interface is
>16 bits for Unibus and Qbus...
Ethan, a very nice implementation of a simple CF
interface is the speccy
one. I don't have a link handy and I'm on a hurry. But look for cf
interfaces for ZX Spectrum and you'll find a very simple way to drive a CF
card. Maybe it can be implemented on your big iron :)
I didn't say "CF", I said "IDE". CF supports 8 or 16-bit access,
in any case, Qbus and Unibus are still 16 bits, and I think using an
8-bit CPU to talk to a Qbus or Unibus will add complexity to the project
vs using a 16-bit CPU.
It's been beaten to death on the list in the past, but CF is not a good
choice for a long-term use with a swapping OS (VMS and Ultrix in this case).
I don't know enough about RSX and RSTS internals to know if they do lots of
writes to the boot drive or not.
Oh... and not all CF-interfaced rotating media support 8-bit mode. I have
a 5GB CF-interfaced drive here (in a USB wrapper), and from researching the
drive mech on Seagate's site, it explicitly does *not* support 8-bit mode,
only 16-bit "true IDE" mode. I was thinking of stuffing onto my IOB6120
until I found that out. I also have a real IBM-branded 340MB Microdrive
with me; I haven't checked on that one yet.
Ethan Dicks, A-333-S Current South Pole Weather at 6-Mar-2008 at 19:50 Z
South Pole Station
PSC 468 Box 400 Temp -40.9 F (-40.5 C) Windchill -78.8 F (-61.6 C)
APO AP 96598 Wind 21.8 kts Grid 17 Barometer 679.7 mb (10640 ft)
Ethan.Dicks at usap.gov http://penguincentral.com/penguincentral.html