On 19-Mar-15 18:43, Johnny Billquist wrote: > > All true. Except I don't think VMS actually do relocation at load > time. The VAX instruction set was capable enough that pretty much all > code you ever wrote was already PIC. The only things to resolve were > external symbols, but I don't think VMS allowed shareable images to > refer to external, unresolved symbols to start with. But I might be > wrong on that. > You are. The image activator dealt with G^ symbol fixups. One tried to avoid them, as they caused imgact to do extra work, and the instructions that needed to be fixed-up made their pages non-sharable. You can write PIC code, on VAX, but don't have to. But that's another diversion, and I have other things to do. > > > And yes, -20F looks truly like a weird hybrid, with even the > documentation not correct. > The documentation is correct, as far as it goes. It's just not complete. Any doc has some errors. And this was reverse-engineered. Be grateful that some of us fought for funding to get the internal notes and training materials published.
> Probably. But unless you also have 11D code, don't be too sure. 11M >> practiced code reuse before it was popular. M may have started with D's >> BOOT. > > Nope. The comments in the BOOT sources even says it is 11M. > That doesn't contradict my point. Its origin may well have been 11D, before 11M adopted it. >> his was the basis of the 20F drivers. > > Loadable device drivers have been around for a long, long time in 11M. > But, unlike 11D, device drivers in 11M were never tasks. I've been around longer. When I first used 11M, they had to be sysgened into the exec. It was big news when they became (optionally) loadable. And somewhat of a pain to upgrade, though avoiding the full exec TKB was helpful when developing. > And the drivers in -20F do appear to be like tasks, and they even > define the RSX11D symbol, so they definitely are in the 11D vein. > As I said, keep looking and you'll keep validating what I wrote. This started when I said the drivers came from 11D, and you disbelieved me... As far as I'm concerned, this conversation is over.
smime.p7s
Description: S/MIME Cryptographic Signature
_______________________________________________ Simh mailing list [email protected] http://mailman.trailing-edge.com/mailman/listinfo/simh
