29 Nov
2016
29 Nov
'16
12:54 p.m.
On 2016-11-29 12:22 PM, Noel Chiappa wrote:
This is great! Are there any other accompanying materials of interest to
QBus hobbyists?
--Toby
From: Peter
Coghlan
Can anyone suggest an existing, simple QBUS
device that I could study
the documentation of to figure out what a basic QBUS device needs to
have and to give me some ideas on how to implement one?
Depends. Do you want to be able to do interrupts? Do you want to be able to
do DMA? Each is a significant increment in complexity.
Later DEC QBUS devices may not be the best things to look at, since they tend
to use special DEC QBUS control chips (I'm _not_ talking about bus
transceiver chips here) which are of course no longer available.
If all you want is master/slave (i.e. the ability to read/write registers),
try this:
http://ana-3.lcs.mit.edu/~jnc/tech/QSIC/test.pdf
It implements a single 16-bit register. (Changing it to support a single
block of registers would of course be trivial.) ...