22 Mar
2019
22 Mar
'19
11:50 a.m.
On 2019-Mar-22, at 11:14 AM, Chuck Guzis via cctalk wrote:
On 3/22/19 10:28 AM, Glen Slick via cctalk wrote:
In that vein:
When I was tasked (1980) with producing a cross-assembler and cross-compiler
for the 68000 for our R&D sys, (Verex OS / Z language), the first operating target
was Motorola's 68000 emulator running on the campus mainframe (MTS on Amdahl / 370).
(Followed by hardware, which was a 68000 exerciser board or a bare SUN-1 processor board).
I'm pretty sure there was also a 68000 cross-assembler from Moto on the Amdahl,
although I'm not sure whether I used it or not, might have to confirm it's output
with the output from mine.
IIRC the Moto programs were written in Fortran (oops, FORTRAN).
On Fri, Mar 22, 2019 at 9:59 AM Chuck Guzis via
cctalk
<cctalk at classiccmp.org> wrote:
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.
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.