Talking of the 380Z...

[Jules Richardson]

On Fri, 2005-07-08 at 23:51 +0100, Tony Duell wrote:
> > Actually, I'd not heard of the blue-cased machines before. Maybe they're
> > in standard off-the-shelf instrument cases rather than with RML logos,
> > panel cut-outs etc.?
> 
> The black case is a standard (Vero iIRC) case. It was designed to take a 
> 19" rack chassis, but RML just mounted the PSU and card guides inside. 
> OK, the cutouts and logos are custom, but that's all.

Yep, that's certainly what it looks like anyway...

> > Oh, Xebec board in my fileserver is an S1410, for which I have a manual
> > and a couple of spare boards, so I can do some messing around with a PC
> > parallel port driver. There's even a sample Z80 interface schematic in
> > the back of the manual that's probably adaptable...
> > 
> > Still concerned about timings though as some of the timing diagrams do
> > have upper constraints on signal changes (a lot of them only specify a
> > minimum limit). Time will tell if the PC's port is quick enough...
> 
> I think (wihtout trying it), you can go as slowly as you like.

Having had a better read of the timing diagrams, that looks to be the
case. The critical one is the time between the target asserting REQ and
the controller asserting ACK - but in all 'simple' SASI/SCSI interfaces
that bit's done in hardware via a flipflop, so time taken for the
software-driven part doesn't actually matter. 

Time to throw a few chips together and have a play around I think...

cheers

Jules