DDOS version 2 is of purely historical interest and may potentially be the the firmware that accompanied the 'stop press' announcement of a double density FS in December 1983 as well as the reference implementation for EDOS. I haven't looked at it thoroughly but v3.00 has had lots of code rearrangement compared to it with *ROMID added of course, as well as <Hex No.> appearing in syntax displays.Slogger don't seem to have been very organised about their versioning, but you can get a ROM identifier kind of thing out of later versions of DDOS by doing *ROMID. Slogger202.rom doesn't respond to *ROMID, so maybe it's too early, but Slogger345.rom reports "3.45 01-02-86 35000".
Greg Cook was keeping a list of DDOS versions at one point, so this one might be of interest to him. It looks to be largely quite similar to the 3.35 with the same ID from his collection, but with some changes towards the end.--Tom
Revision 3.5 adds a special check and error message for write protected discs while writing the catalogue, as this would be the commonest time the error would be noticed. It's the DDOS 3.46 series, then, that adds a routine to fetch the user's sector ID table to format a track, which is of course required when generating a track buffer for the WD 1770 controller. Those ROMs and Challenger 1.00 introduce the fetch routine at different points in the ROM, confirming that emulation of OSWORD &7F command &63 (format track) was developed after the fork of Challenger 1.00 from DDOS 3.45 revision 3.0. In previous revisions, including this newly found ROM, command &63 is an interface to the WD 1770's Write Track command, and programs expecting an Intel 8271 implementation fail to create a working disc.
That was a deep dive. I'll update my spreadsheet with the details shortly.
Edit: Unknown4 is a DFS 0.9 ROM with a bad case of bit rot.
Statistics: Posted by regregex — Tue Apr 02, 2024 8:01 pm