Front Panels - Thoughts

Mike Stein mhs.stein at
Sun Nov 1 15:47:20 CST 2015

Brent Hilpert wrote:
> One problem with a front panel on an S100 machine - or any
> microprocessor-based machine - is getting access to the program
> counter so you can tell it to start running at some arbitrary
> address. The Altair/IMSAI panels resolved this with a hack, jamming a
> jump instruction into the processor data lines (not the S100 bus data
> lines) via a special connector to a special processor card.     
> In general, even if you can bus master to put stuff into memory,
> front panel functionality is pretty limited if you don't have control
> ever execution.  

Regarding Cromemco, they did sell a blinkenlights
Z-1 which was  essentially a Cromemco backplane
and cards in an IMSAI chassis.

Their ZPU processor card does have several option 
jumpers to make it compatible with a front panel.


More information about the cctech mailing list