Homebrew QBus designs - was Re: VAX 4000-100 QBUS cables
toby at telegraphics.com.au
Tue Nov 29 11:54:46 CST 2016
On 2016-11-29 12:22 PM, Noel Chiappa wrote:
> > 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:
> It implements a single 16-bit register. (Changing it to support a single
> block of registers would of course be trivial.)
This is great! Are there any other accompanying materials of interest to
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