Q-bus I/O project

[Jay Jaeger]

Quite a piece of work.  I hope you can continue to plug away at it.

I get that bit about mistakes.  Even my simple PIC-based Documation card
reader interface board had a mistake (fortunately, one I could easily
fix without having to create a new board).  Fortunately, my Mark-8
boards ended up mistake free, but only because of hours and hours and
hours of cross-checking against the layouts in the Radio Electronics
sponsored flyer, the schematics and against know issues.  But those were
nothing like this thing's complexity.

JRJ

On 10/9/2015 8:38 PM, John Wilson wrote:
> This may never see the light of day (if the prototype turns out to be
> stillborn) but it's pretty and I can't resist posting a pic before I've
> powered it on and proven its uselessness:
> 
> 	http://www.dbit.com/wilson/projects/qba.jpg
> 
> Officially it's for my morally repugnant attempts to earn a living (so it's
> supposed to be a Q-bus bridge that connects over Ethernet), but I wanted to
> still be able to do something fun in the very likely case that the Ethernet
> port doesn't work (no idea if my PCB layout is kosher for something as fast
> as the gigabit PHY's bus) or has uselessly high latency, so I added an SD
> card slot and made all the CPU-end terminators switchable, so it can act
> as just a plain peripheral (I'm mainly thinking disk controller -- I've
> already found a reason why the USB device port can't work), if its CPU's
> alive and can talk to the Q-bus.  We'll see.  Many many many chances for
> mistakes.  Five different power-supply voltages, for starters.
> 
> As always, I can't say enough good things about XMOS microcontrollers and
> OSHpark.com.
> 
> John Wilson
> D Bit
>