> A hand assembled program entered in binary dip switches enabled a hex
keypad.

Hex keypad!
You had a hex keypad ! ????????????

When I was a boy we only had binary switches for all input (address and
data).
The SC/MP (Nat Semi's fond nightmare)  had a convenient 'step one step and
stop while outputting address lines' mode which allowed data entry to RAM
using the cpu as an address counter. Then reset and run.

My greatest programming joy (possibly ever?) was the first time I persuaded
a D2 kit to read a block of data from an 8 track magnetic tape drive into
the 6802's buffer. Flick - 1 block read. Wasn't sure it had actually worked
until I had rewound the tape, zero'd RAM buffer and read it again and
compared the data. Had to steal the stack pointer and use it to store data
to get the loop speed fast enough to handle the tape. 1 MHz clock afair.



    Russell "uphill to school both ways, in the snow,
        without shoes, at the bottom of a lake in a
            cardboard box*" McMahon

* See archives of years gone by for explanation, if needed :-)

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