I want a front panel for my lsi 11 w/switches and lights

Noel Chiappa jnc at mercury.lcs.mit.edu
Mon Mar 7 06:41:24 CST 2016

    > From: Ed Sharpe

    > I want a front panel  for  my lsi 11  w/switches and  lights! 

That's going to be a little tricky. The LSI11 obvously doesn't have a hardware
interface on/in the CPU which would allow a lot of the functions traditionally
found in a front panel (e.g. examining registers, single step, etc).

Some of them can be done (e.g. a halt/run switch, which LSI-11's already
support), and others could be 'sorta' done - e.g. if the CPU is running, DMA
could be used to read/write memory locations.

Probably the best way to have an emulated front panel is to build a board
that i) emulates the system serial console on the QBUS (i.e. responds to
177560-6), and ii) has a micro or something which uses ODT to emulate the
full range of normal console commands, and drives a set of LEDs and switches.

E.g. hitting the 'continue' switch when the processor was halted would issue
a 'P' command to ODT; when the 'halt' switch is raised, it would read the PC
printed when the CPU halted, and display that in LEDs, etc, etc.

Sounds like an amusing project for someone. Any takers? :-)


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