8085 Dissasembly?

Bill Gunshannon bill.gunshannon at hotmail.com
Tue Apr 17 13:52:08 CDT 2018

On 04/17/2018 02:21 PM, Chuck Guzis via cctalk wrote:
> How many started coding for a machine writing machine code?
> I recall that the IBM 1620 SPS coding forms had two sides--one for
> coding assembly (SPS); the other labeled "IBM 1620 Absolute Coding
> System".  Basically a form with the first 5 positions reserved for the
> address, 2 positions for the opcode and 5 positions each for the P and Q
> addresses.
> You could enter the code from the form right into the console typewriter
> or punch it on a keypunch.  If you were a real hard-case, you didn't
> bother with coding forms, you sat down at the typewriter and did
> everything from memory, mentally keeping track of storage addresses and
> what referenced them.
> Do this for a while and disassembly is easy.  After all, you'll have all
> of the instructions and their opcodes committed to memory.
> I believe that I can still do this for 8080 code, in spite of my
> deteriorating wetware.

Well, the first programming I learned was Autocoder on the IBM 1401.
Our instructor gave us a simple project (80/80 Print). Had us write it in
Autocoder and verify that it worked. Then we had to optimize it to
reduce it to fit on a single punched card.  That was done by tweaking
the machine code output by the Autocoder "compiler".  I still have mine
around here somewhere.


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