Re: [TUHS] Work I've done with a PDP-11 simulator

The web page mentions files-11 which is ODS-1. Technically (it is all coming back to me now): FILES-11 is a family of file systems that started in RSX-11 (or perhaps before but that's the oldest instance I know). ODS-1 is really FILES-11 ODS-1; ODS is `on-disk [something].' RSX-11 used ODS-1. VMS used ODS-2. I'm not sure of all the differences offhand, but they were substantial enough that we ended up writing two different programs to fetch files to UNIX from RSX and VMS volumes (we had the latter to deal with too). Certainly the directory entries were different between the two: ODS-1 used RADIX-50-encoded file names with at most six characters plus an at-most-three- character `extension' (a term which newbies sometimes improperly import into UNIX as well); I forget the exact filename rules in VMS, but filenames certainly could be longer than six characters. I've found the early-1980s programs I remembered. There were two, getrsx.c and getvms.c; two programs, one for each file-system format. They are surely full of ancient sloppiness that won't compile or won't work right under a modern C compiler, and they make assumptions about byte order. I'll spend some time in the next few days going over them and see if I can quickly get something workable. A footnote as to their origin: in the world where we wrote these programs, we had not only multiple systems, but shared disk drives. The disk drives themselves were dual-ported; the controllers we used could connect to multiple hosts as well. Each system had its own dedicated disk drives, but the UNIX systems could also see the drives belonging to the RSX and VMS systems; hence the file-fetching programs, since this was well before the sort of networking we take for granted these days. On the other hand, we had several UNIX systems which spoke uucp to one another, and that was occasionally used for large file transfers. To speed that up, I taught uucico a new protocol, whereby control information still went over a serial line, but data blocks were transferred over a chunk of raw shared disk (with appropriate locks, of course). It was a simpler world back then, but that made it a lot more fun. Norman Wilson Toronto ON