8080 Assembler-Text Editor (ATE)

Chuck Guzis cclist at sydex.com
Mon Apr 17 17:53:46 CDT 2006

On 4/17/2006 at 6:20 PM Dave Dunfield wrote:

>By the time the Z80 was common, so were good assemblers and
>debuggers - but when the 8080 (ie: this instruction set) was designed,
>there was no such software commonly available for "personal use" -
>chances are your assembler was a pad of paper, a pencil and the Intel
>databook (thats how I wrote my earliest software).

When I started to get into microprocessors, I wrote my own 8008
cross-assembler--and I used hex on a CDC 6600 (which was, curiously, an
octal machine--60 bit words with 6 bit characters).  It just made sense.  I
never finished the 8008 machine I was building, but went for the 8080 when
it came out as the MITS box.  I revised the 8008 assembler  to assemble
8080 codes.   IIRC, my assembler was a one-pass job.  There wasn't any good
reason to write a two-pass assembler, given the simplicity of the code I
was writing.

Hex actually made a lot of sense, not only from the standpoint of 8-bit
characters, but also due to the decimal arithmetic available on both the
8008 and 8080 MPU's.  Try reading packed decimal coded in octal!


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