24 Feb
1998
24 Feb
'98
12:12 a.m.
On Mon, 23 Feb 1998, Tony Duell wrote:
...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.
-jim
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jimw(a)agora.rdrop.com
The Computer Garage - http://www.rdrop.com/~jimw
Computer Garage Fax - (503) 646-0174
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.