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

Charles Dickman chd at chdickman.com
Tue Nov 29 12:24:03 CST 2016

On Tue, Nov 29, 2016 at 12:54 PM, Toby Thain <toby at telegraphics.com.au> wrote:
> 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.

The DEC Chipkit documentation has the internal schematics for the
standard DEC interface chips and is very much worth a read.

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