[fpc-pascal] MS DOS 8086 compiler?

Marco van de Voort marcov at stack.nl
Sun Apr 28 16:14:02 CEST 2013


In our previous episode, Mark Morgan Lloyd said:
> > Actually, I have a vintage IBM PC 5150, with a 4.77 MHz 8088 processor, 
> > so this isn't true, it's very testable actually :) However, the i8086 
> > code generator still generates some 186/286+ instructions, so it doesn't 
> > work there yet, but I'm planning to fix this shortly. Here's a video of 
> > a few very simple Free Pascal compiled programs on a true 80186:
> 
> OK, answering my own question then. A pure-8086 port could be valuable 
> if it generated reliable code for something like vtprolog.pas, since 
> this implements its own garbage collection relying on detailed knowledge 
> of how Turbo Pascal manages its heap.

Heap management is mostly a RTL feature. For high TP compatibility, things
like calling conventions must also match.

IOW 8086 codegeneration is not automatically full TP compatibility on the
binary level.



More information about the fpc-pascal mailing list