[Simh] Interdata OS/32: hello-world in CAL32

[Armistead, Jason BIS]

On Feb 23, 2016, an anonymous user (lists at openmailbox.org) wrote:

> Thanks very much for the additional info. Your post was very timely since I read in the notes that come with the PL/M cross compiler
> that is being discussed that it was a cross-compiler hosted on MTS and VM/CMS.

> I don't think I ever came across a cross compiler in the old days. It is interesting to see that people used these odd combinations.

> I wonder if we should start trying to archive and document cross compilers specifically.

> On Tue, 23 Feb 2016 01:01:28 -0500
> johnsong at gregjohnson.org wrote:

> [very nice story snipped]

Cross compilers were great when your target system didn't have enough memory, storage, and possibly no actual operating system to support a locally-hosted compiler.  For a language like PL/M-86 which had no language specific I/O constructs beyond reading to and writing from I/O ports on the target CPU, it was perfect for writing applications for an OS-less embedded systems, but it needed a host.  Hosting on a VAX under VMS might be viewed as a little extreme when the target had less than 64K of EPROM and a few K of RAM, but it worked.  The only complaint I had is that Intel limited the symbol table sizes somewhere in the linker (IIRC !), and you could exceed the maximum number of external symbols, thus requiring some splitting of modules and multi-step linking to resolve this dilemma.  I suspect the origins of this limitation was the MS-DOS environment with 640K of memory (Intel's tools didn't use a DOS extender), and that whoever ported the toolset to VAX/VMS never increased this limitation, even though VAX/VMS could support a lot more than virtual memory than DOS.

Assemblers were a little bit easier to host on a target - smaller code size in your editor, no optimization required, etc., though plenty of cross assemblers certainly existed for a wide range of targets, especially those that were embedded like Intel 8048 & 8051, Motorola 680x, etc.

A lot of the "classic" embedded cross compiler/cross assembler companies are no longer in existence, either gobbled up by larger companies, or simply going the way of the Dodo bird.  Names like Franklin, 2500AD, Avocet System, Adtek (from Japan) and Hi-Tech (from Queensland Australia), were pretty common players, but these days their products are no longer available, or if you're lucky they are end-of-life and provided as-is with no support, even if you buy them.  Intel created their own systems, like the Intel's iPDS-100 running ISIS-II, or Motorola/Freescale (now NXP) got 3rd party vendors like P&E Micro to do some of their tools and development boards.  It was a wild time !!!

PS: I'd love to see an iPDS-100 emulation in SIMH one day !!!