Atlantis wrote:
I think that the easiest solution will be to start with some Monitor program instead of rewriting this Basic interpreter to work as a standalone piece of software.
If that BASIC is dependent on external routines, you can't just drop in any old monitor and hook it up; each monitor is different from each other monitor, sometimes vastly so.
I think that the easiest way to go at this is to do what amounts to fairly standard reverse-engineering job on this: start with the entry point to the source you have, walk through it until you find where it breaks, and then start writing the bits of code you need to make things work. I'm happy to help out with more details on getting that set up if you want to contact me via a private message here. (Actually, I already sent you one about something else.)
BTW, I have written a 6800 CPU simulator and machine-code unit test framework (found
in here) that might be useful to you as well, especially if you're not highly confident in writing 6800 code that works the first time. The unit test framework also works for 6502, using py65 as the CPU simulator.
BigEd wrote:
It's true though that expertise here on the 6502 is widely held, but on the 6800 a bit more thin.
Well, certain CPU-specific expertise, yes. But in many areas 6502 systems expertise is also 6800 systems expertise because so much was inherited from the 6800 world, such as the bus design. Some might say even "stolen," given the propensity to directly use Motorola 6800-series parts (e.g., the 6821 and the 6850) and make almost exact copies of them (6520 and 6550).
That may be the reason that there's probably more 6800 systems expertise here than there is on anycpu.org.
And let's not forget that much 6800 work can be fairly easily ported to 6502 systems, to the advantage of the 6502 community. As one example, that unit test framework above, which would have been trivially ported from 6800 to 6502 had I not started from the other direction. :-) (Still, doing a 6800 version definitely improved the 6502 version as well.)