Sheesh! January so far has been insanely busy with overtime at work, and if you add in the start of the Mens’ hockey season and the first Firemans’ Run of 2016, I am turning up a little late to this months’ Retrochallenge event.
My original intent was to get started 10 minutes after the start of 2016, not 10 days after. However, as is often the case, as well as paid work, some hardware distractions took over from the supposedly software project: dreaming of HY6264 parallel SRAMs, 74HC138 address-decoders, MC6850 ACIA serial-interface chips, 74HC373 bus demultiplexers, micro OLED screens, 28HC64 parallel EEPROMs, and also what on earth to do with a shed-load of serial RAM chips. Get a grip, man!
Of course, there was also the (strangely recurring) task of repairing an acquaintances’ “dropped it down the stairs and smashed the screen and internal disk-drive” laptop. No, of course there isn’t any recovery-/reinstallation-disc, nor any backups. I might have to cut down on doing these kind of favours!
Restart and Restatement:
My project-introduction posted last month was a bit of a rambling discourse written in the style of a disjointed rant (!), so perhaps I had better restate the task in a rather more direct way:
“To retarget an ancient closed-source MSDOS C compiler to generate programs for a proprietary closed-source 6th Edition UNIX clone (8086-based).”
I do not have any of the runtime libraries or C-runtime-startup object-code files for the target system (Whitesmiths Co-Idris/86), nor any documentation of the system-call sequence. So part of this project is going to be low-level reverse-engineering and general cheating.
The Dead Trees Society:
I come to the project armed with some old paper-only Whitesmiths’ manuals, which were much better than the old AT&T 6th Edition UNIX manuals – actually organised properly by topic and are-of-interest, with useful tutorial sections as well as the reference pages. I have had these since March 1991, gathering a copious layer of dust over the last 24 years, so I guess now is a good time to make at least a little use of them!
The following posts will summarise the contents of these manuals, as it might just be at least a little illuminating. As always, of course, I am missing the one manual that would make the task possible: the “Whitesmiths 8086 C Interface Manual”. The PDP-11 and 68k C interface manuals that I have are not going to be much help here!