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@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