Hi, > I'm wondering if anybody has any experience, or has seen any source > code, related to manipulating the DOS Swappable Data Area (SDA) to > make DOS re-entrant. I working on at least one TSR program right > now where I think something like that might be useful but I've never seen it > done before.
I think it was sort of documented in "Undocumented DOS 2nd edition", AFAIR even with some (demo) code. I needed something like that in ~1992, and spend quite some time to get it running. In the end, I got it mostly running, but not really stable in a sense that it worked pretty well unless I ran some testprograms in the foreground intended to stress this interface. It probably can be made to work, but I failed to do that, and finally gave up and used other ways with the same effect (for my TSR's purpose). > The SDA of MS seems fairly well documented in RBIL, but I'd be > pretty surprised if all DOS clones (particularly Virtual Machines > like DOSBox) are compliant so it may not be a good idea to pursue. probably right. > I suspect FreeDOS would be pretty close to compliant, but I'm not even sure > about that. I would be absolutely surprised as it never came up as a thing to do, and would be 100% untested as nobody uses the SDA to multitask the last 20 years. > But I was still wondering if anybody has seen it done before since > I don't think I've ever seen an actual implementation. neither did I. Tom _______________________________________________ Freedos-devel mailing list Freedos-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-devel
