Forum OpenACS Q&A: Re: compiling OMSI PASCAL programs in DEC RT57XM monitor

Posted by Don Baccus on
Not sure why you're posting an OMSI Pascal question here at OpenACS but you've lucked out ...

I'm one of the two principal authors of the old PDP-11 OMSI Pascal compiler you're referring to. I did the work under contract to ESI while in college. No development work has been done on that compiler since the late 1970s.

The compiler uses the standard RT/11 device drivers and the standard API to load and reference them. You should ask Mentec if they've modified the application-OS API. If not, drivers shouldn't be a problem.

A more likely source of the dump to ODT is memory management. Clearly this has changed since 4 MB is being made visible to the operating system and applications. The PDP-11 is a 16-bit computer and the original architecture only allowed direct reference to 64KB total, 32KB in I[nstruction] space and 32KB in D[ata] space. Obviously changes were made to make 512KB available and even more changes to make 4MB available.