Homebrew QBus designs - was Re: VAX 4000-100 QBUS cables

Toby Thain 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:
>   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.)

This is great! Are there any other accompanying materials of interest to 
QBus hobbyists?


> ...

More information about the cctech mailing list