On Sun, 23 Oct 2016 14:07:33 -0400 Paul Koning <[email protected]> wrote:
> I've never seen DOS sources. Also, DOS/Batch is a later version with > more stuff in it. DOS V4 might be better. I couldn't agree more. We had DOS/BATCH on an 11/20 in about 1974 (we'd had it for a year or two before I got my hands one it). I know someone had to patch it as it used 12 bits for the date: date = (year-1970)*1000 + day in month They called it a Julian date (which it wasn't, and of course it was incredibly bit-wasteful). It 'ran out' in March 1974, and the patch was regularly applied to fix dates so that we worked in the middle of a four year window. We also put it on RK05s, and I remember reading the (badly xeroxed) sources that DEC gave us, and working out how to patch it to fix a fairly nasty bug in the RK05 driver. But it was amazingly small - 4kB resident, with hundreds of tiny overlays. I think running a program used four 128kB overlays. > On the other hand, DOS is a truly evil operating system. I don't > know its internals, but just from using it you can tell it should > never be used as a model. Indeed! I did fire it up on SIMH a while ago. > RT-11 is very clean. I've worked with V2A (the FB version when > possible, SJ when I didn't have enough memory). They are very simple > and compact; the UI is the old TOPS-10 style, not the newer bloated > "DCL" interface. So a V2 era edition would be a good way to go. Yes, it's very nice. Someone once gave me electronic copies of some sources (circa 1975) and I read them with glee. Lovely comments, too: the system call dispatcher had the comment "What's it going to be then, eh?" from the Clockwork Orange. I think those comments were only in the FB monitor. I assembled it on DOS/BATCH, and wrote programs in MACRO-11 to convert the binaries to RT-11 format. I also wrote stuff to make a bootable DECtape, got it running, and used that to transfer it to disk! _______________________________________________ Simh mailing list [email protected] http://mailman.trailing-edge.com/mailman/listinfo/simh
