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!

Cheers,
Chuck





More information about the cctech mailing list