front panels

From: James Willing <>
Date: Tue Feb 24 00:12:05 1998

On Mon, 23 Feb 1998, Tony Duell wrote:

> >
> > The one thing you could do with a real front panel (not the debugger ROMs
> > and a keyboard/LED display) is debug new card designs. Remember the Morrow
> Which reminds me of my only moan with the PDP8/e and P850 panels - you
> can't access I/O devices directly from them. You have to enter a little
> program (OK, only about 4 instructions) first.
> The Intellec MCS8i and the PDP11 (obviously, since all I/O is memory
> mapped) do allow you to access I/O devices directly from the panel.

...and the front panel on the Altair 8800b.

It has function switches on the front panel that allow you to load or
display the contents of the accumulator, and input/output directly to any
I/O port.

This little bit of magic done by code stored on a 1702 eprom on the front
panel PC board, and some sequencer logic that forced it onto the processor
data bus when the appropriate switches were hit.

The Computer Garage -
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Received on Tue Feb 24 1998 - 00:12:05 GMT

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