rx01 w/o controller board

[Tony Duell]

> 
> On Apr 5 2005, 19:21, Allison wrote:
> 
> > The state machine is a simple but programable non-von cpu that can do
> > the needed tasks to execute complex command to seek, read or write
> > a sector.  The RX02 is a 2901based bitslice that does more as it
> > has to do the needed tricks for DD format.
> 
> Ah yes, I'd forgotten that.  Thanks for reminding me where I'd seen
> another 2901!

It was the first 2901 'system' I ever worked on. I can remember some 
train journeys between Bristol and London where I sat commenting the 
microcode (I'd dumped out the ROMs -- remarkably easy on the RX02 since 
grounding an IC pin that was otherwise pulled up to +5V disabled the 
sequencer outputs and let you take over the PROM address lines). I wrote 
a disassembler, produced a listing, and spent quite a time commenting and 
understanding it. I learnt a lot from that.

-tony