Preparing for my demo video of the MPF-IP BASIC, another Microprofessor MPF-IP enthusiast I was chatting with on another forum just complained that his BASIC wouldn't print properly beyond 18 characters, and that certain BASIC statements documented in the manual don't work (SON, SOFF).
I said, what do you mean? My BASIC just works fine, no issues with the printer, and SON / SOFF work flawlessly!
He then pointed me to the BASIC ROM image he was using:
I grabbed it and burned an EPROM, and indeed - this version must be a prior version and has these issues! For printouts, you'll have to limit yourself to 18 characters per line, else your printout looks as follows:
Now, my original BASIC ROM is indeed working fine, has SON / SOFF, and printing works fine beyond 18 characters:
Seems the MPF-IP BASIC got a major update. There is no obvious version number encoded in the ROM image (at least not in ASCII).
Comparing the ROMs a bit, I see that they even omitted the READY prompt in order to accommodate the patches and SON & SOFF... the new version goes to 0x1ff8, whereas the "buggy" version has 0x1ff3 as last address. So a few bytes more. They really used almost all of the 8 KBs in the 2764!