What 6502 macro assembler was used for the AIM-65 Monitor ROM?

[Chuck Guzis]

On 3/22/19 10:28 AM, Glen Slick via cctalk wrote:
> On Fri, Mar 22, 2019 at 9:59 AM Chuck Guzis via cctalk
> <cctalk at classiccmp.org> wrote:
>>
>> At the expense of being boo-ed for this, could the original Rockwell
>> stuff perhaps have been assembled using a mainframe/mini-hosted
>> cross-assembler?
>>
>> I'm aware of several situations where this was the case.
> 
> The date in the AIM-65 Monitor Program Listing header block in the
> source code is Aug 22, 1978. That is less than 1 year after the
> introduction date of the VAX-11/780. I suppose it still could have
> been something that ran on a VAX by then, or a PDP-11 (or PDP-10?), or
> some other mainframe/mini host if it wasn't self hosted on a Rockwell
> 6502 development system.
> 
> It's really just more of a curiosity issue at this point if anyone
> finds a definitive answer.

Many cross-assemblers for early MPUs were written in (shudder!) FORTRAN.
 There were several good reasons for this.

The first is that if you had a mini or mainframe, you were pretty much
guaranteed to have FORTRAN, which had been implemented under various
standards since 1966.

The other is that in the 70s, there was still a population of six-bit
character machines not using ASCII, not to forget the ones using EBCDIC.
 So hard-coding character sets into programs that were supposed to be
portable over a wide range of machines was an issue.

I think some of the old FORTRAN code for PALASM may still be around, as
an example.

--Chuck