DOS ain't dead

stable release ready BUT... (Announce)

posted by ecm  , Düsseldorf, Germany, 03.12.2009, 18:04

> Rather, by the fact that using a classical DOS block device driver
> requires rather rigid structures, including a DPB which in turn assumes
> the existence of a FAT, all of which can't be applied to CD volumes.

Exactly.

> > Redirected drives don't need DOS devices.
>
> I didn't say they did!

> >> But the CD (and DVD) drivers are special devices which don't fit well
> >> in the old DOS driver model, being treated as network drives, hence
> >> each of these devices need both a /character/ mode driver specific to
> >> the device model and the MSCDEX or compatible redirector.

Sorry. It sounded that way too me.

> So, the MS network redirector dressing of network drives, or CD-ROMS etc,
> as if they were local FAT units, is the illusion.

You forget that at this level (Int21 and up) there's no knowledge about the concept of block devices anymore. You're right now, stating that the native and the redirected drives look the same there. Previously you said "the illusion of a block mode device". This however doesn't make much sense to a user who doesn't know what a block device is.

> > Of course most device drivers can now be loaded
> > either by DEVLOAD or by updating them to load as executable too
>
> But probably not the CD-ROM drivers :( Have you ever heard of one that
> could be devloaded ? A possibly interesting research subject.

I didn't have any issues loading a CD-ROM device driver with DEVLOAD, then MSCDEX or SHSUCDX. It wouldn't make sense to have issues there. In DOS terms the CD-ROM device drivers are very simple: a proper name, allow IOCTL Read/Write and that's it.

> Internal MS-DOS UMA and HMA management did not change from DOS 5 until DOS
> 8 AFAIK.

Seems to be true for the UMA management (as mentioned), but the HMA management requires you to know where and how DOS fixes up entry points as well as the size of the DOS code segment, or even more. At least the code segment's size changed between most or all of the versions from MS-DOS 5.

---
l

Complete thread:

• HK31.SYS *beta* announce & discussion thread - Ninho, 26.11.2009, 17:04 (Announce)
  • HK31.SYS *beta* announce & discussion thread - Ninho, 28.11.2009, 22:07
    • HK31.SYS *new version* beta 0.9 - Ninho, 29.11.2009, 16:58
      • HK31.SYS *new version* beta 0.9 - ecm, 29.11.2009, 17:15
        • HK31.SYS *new version* beta 0.9 - Ninho, 29.11.2009, 17:25
  • stable release ready BUT... - Ninho, 01.12.2009, 17:50
    • stable release ready BUT... - ecm, 01.12.2009, 19:46
      • stable release ready BUT... - Ninho, 01.12.2009, 20:00
        • stable release ready BUT... - ecm, 01.12.2009, 22:56
    • stable release ready BUT... - Japheth, 01.12.2009, 21:03
      • stable release ready BUT... - Ninho, 01.12.2009, 22:38
        • stable release ready BUT... - Rugxulo, 01.12.2009, 23:17
          • stable release ready BUT... - Ninho, 02.12.2009, 00:00
            • stable release ready BUT... - Rugxulo, 02.12.2009, 00:16
              • stable release ready BUT... - Ninho, 02.12.2009, 17:51
            • stable release ready BUT... - ecm, 02.12.2009, 18:25
    • stable release ready BUT... - Doug, 02.12.2009, 01:15
      • stable release ready BUT... - Ninho, 02.12.2009, 09:23
        • stable release ready BUT... - ecm, 02.12.2009, 18:34
          • stable release ready BUT... - Ninho, 02.12.2009, 19:24
            • stable release ready BUT... - Doug, 02.12.2009, 22:08
              • stable release ready BUT... - Rugxulo, 03.12.2009, 01:12
              • stable release ready BUT... - Ninho, 03.12.2009, 12:53
                • stable release ready BUT... - ecm, 03.12.2009, 14:20
                  • stable release ready BUT... - Ninho, 03.12.2009, 16:39
                    • stable release ready BUT... - ecm, 03.12.2009, 18:04
  • "HACKWRAP.SYS" out of beta (so I hope...) - Ninho, 03.12.2009, 20:25