> From: Mattis Lind
> What about the M9300 board? Do you have an idea what the purpose is of
> that card?
Yes, that one's well-documented and understood.
It's intended for use on the 'B' UNIBUS of the RH11-AB, in deployment
configuratons where that UNIBUS is in use, but there's no CPU on it to
respond to NPR bus requests.
(See:
http://www.bitsavers.org/pdf/dec/unibus/RH11_Peripheral_Controller_Course.pdf
pg. 11 for an example; the 'B' UNIBUS of the -11/45 is used for a separate
path into the 45's dual-port FASTBUS memory.)
On such a UNIBUS, the M9300 is used at the start of the bus, and is jumpered to
allow on-board circuitry to respond to an NPR with an NPG.It also has a SACK
timeout capability, documented in:
http://www.bitsavers.org/pdf/dec/unibus/RH11-AB_OptionDescr.pdf
on pp. 69-70, but I'm not fully familiar with that.
Noel
