DOS ain't dead

New version DRDOS 7.01.7 & 7.01.8 (Announce)

posted by ecm  , Düsseldorf, Germany, 12.12.2023, 18:47

> I made some changes to the latest EDR-DOS sources maintained by ecm:
>
> - fixed bug in DRDOS.SYS div32 function, leading to division errors on
> partitions with more than 66535 FAT sectors. There is also a div32 function
> in DRBIO.SYS present, but it did not contain the bug.

https://github.com/SvarDOS/edrdos/commit/167fe71ec058f80b7da47f11f2a34fc66938ad57

div16:
        mov     ax,12[bp]
        mov     dx,14[bp]

Surely you can xor dx, dx here if you already checked that word [bp + 14] is zero?

More to the point if the divisor high word is zero, a two-step division of two 32/16=16 divisions can be done on a 32-bit dividend (with 32-bit quotient) which would be faster than the full 32-bit division (that fully supports 32-bit divisors in addition to dividends/quotients).

The division functions in DRBIO both do not offer the fast path for smaller numbers:

https://github.com/SvarDOS/edrdos/blob/f6584d40d6dda553e63f7682ad672536f53ae6ff/drbio/disk.asm#L3286

https://github.com/SvarDOS/edrdos/blob/f6584d40d6d...e63f7682ad672536f53ae6ff/drbio/bdosldr.a86#L772

---
l

Complete thread:

• New version DRDOS 7.01.7 & 7.01.8 - CandyMan, 21.07.2023, 15:40 (Announce)
  • New version DRDOS 7.01.7 & 7.01.8 - glennmcc, 21.07.2023, 20:13
  • New version DRDOS 7.01.7 & 7.01.8 - nico7550, 21.07.2023, 20:27
    • New version DRDOS 7.01.7 & 7.01.8 - fritz.mueller, 21.07.2023, 20:29
      • New version DRDOS 7.01.7 & 7.01.8 - glennmcc, 21.07.2023, 20:34
    • New version DRDOS 7.01.7 & 7.01.8 - CandyMan, 21.07.2023, 22:18
      • New version DRDOS 7.01.7 & 7.01.8 - nico7550, 21.07.2023, 22:45
        • New version DRDOS 7.01.7 & 7.01.8 - nico7550, 22.07.2023, 09:40
          • New version DRDOS 7.01.7 & 7.01.8 - CandyMan, 22.07.2023, 23:06
  • New version DRDOS 7.01.7 & 7.01.8 - Guti, 24.07.2023, 11:08
  • New version DRDOS 7.01.7 & 7.01.8 - CandyMan, 25.07.2023, 15:04
    • New version DRDOS 7.01.7 & 7.01.8 - nico7550, 26.07.2023, 15:19
      • New version DRDOS 7.01.7 & 7.01.8 - Guti, 30.07.2023, 11:12
  • New version DRDOS 7.01.7 & 7.01.8 - DieTotenByte, 30.07.2023, 01:09
    • New version DRDOS 7.01.7 & 7.01.8 - CandyMan, 30.07.2023, 10:55
  • New version DRDOS 7.01.7 & 7.01.8 - CandyMan, 03.08.2023, 21:46
  • New version DRDOS 7.01.7 & 7.01.8 - CandyMan, 10.08.2023, 11:09
    • New version DRDOS 7.01.7 & 7.01.8 - ecm, 10.08.2023, 15:52
      • New version DRDOS 7.01.7 & 7.01.8 - CandyMan, 10.08.2023, 19:21
      • New version DRDOS 7.01.7 & 7.01.8 - CandyMan, 11.08.2023, 10:47
        • EDR-DOS bugs on int 21h functions 7142h and 71A6h - ecm, 12.08.2023, 21:13
          • EDR-DOS bugs on int 21h functions 7142h and 71A6h - CandyMan, 13.08.2023, 11:16
            • EDR-DOS bugs on int 21h functions 7142h and 71A6h - ecm, 13.08.2023, 13:59
              • EDR-DOS bugs on int 21h functions 7142h and 71A6h - ecm, 13.08.2023, 14:39
              • EDR-DOS bugs on int 21h functions 7142h and 71A6h - CandyMan, 13.08.2023, 19:23
                • EDR-DOS bugs on int 21h functions 7142h and 71A6h - ecm, 13.08.2023, 21:41
                  • EDR-DOS bugs on int 21h functions 7142h and 71A6h - CandyMan, 13.08.2023, 22:41
                    • EDR-DOS bugs on int 21h functions 7142h and 71A6h - ecm, 13.08.2023, 23:18
                      • EDR-DOS bugs on int 21h functions 7142h and 71A6h - CandyMan, 13.08.2023, 23:51
                        • EDR-DOS development - ecm, 14.08.2023, 07:18
                          • EDR-DOS development - CandyMan, 14.08.2023, 09:43
                            • EDR-DOS development - ecm, 15.08.2023, 20:49
                              • EDR-DOS development - ecm, 15.08.2023, 20:51
                            • EDR-DOS development - ecm, 19.08.2023, 19:56
                          • EDR-DOS development - CandyMan, 14.08.2023, 14:35
                            • EDR-DOS development - bretjohn, 14.08.2023, 21:12
                              • EDR-DOS development - CandyMan, 15.08.2023, 11:49
                        • EDR-DOS development - ecm, 15.08.2023, 20:46
                          • EDR-DOS development - CandyMan, 15.08.2023, 22:29
                            • EDR-DOS development - ecm, 16.08.2023, 10:06
                              • EDR-DOS development - CandyMan, 16.08.2023, 12:54
                                • EDR-DOS development - ecm, 16.08.2023, 18:19
                                  • EDR-DOS development - CandyMan, 16.08.2023, 18:55
                        • EDR-DOS development - ecm, 20.08.2023, 01:35
                          • EDR-DOS development - CandyMan, 21.08.2023, 00:27
                            • EDR-DOS development - ecm, 21.08.2023, 22:54
                            • EDR-DOS development - ecm, 29.08.2023, 17:49
                              • EDR-DOS development - ecm, 29.08.2023, 18:26
                                • EDR-DOS development - ecm, 29.08.2023, 18:32
                                  • EDR-DOS development - ecm, 29.08.2023, 18:49
                              • EDR-DOS development - Rugxulo, 29.08.2023, 23:28
                                • EDR-DOS development - ecm, 30.08.2023, 09:47
                          • EDR-DOS development - roytam, 29.12.2023, 15:33
                  • EDR-DOS repository - Ro2003, 10.10.2023, 16:24
                    • EDR-DOS repository - ecm, 12.10.2023, 19:04
                      • EDR-DOS repository - Ro2003, 13.10.2023, 08:23
                        • EDR-DOS repository - nico7550, 13.10.2023, 15:53
                        • EDR-DOS repository - Single-file kernel load - ecm, 13.10.2023, 18:16
                          • EDR-DOS repository - Single-file kernel load - ecm, 13.10.2023, 18:23
                  • EDR-DOS version number - Ro2003, 10.10.2023, 16:32
                    • EDR-DOS version number - ecm, 12.10.2023, 19:08
  • New version DRDOS 7.01.7 & 7.01.8 - glennmcc, 13.08.2023, 22:19
    • What ever happened to Udo ? - glennmcc, 29.08.2023, 23:04
    • New version DRDOS 7.01.7 & 7.01.8 - Ro2003, 10.10.2023, 16:10
      • New version DRDOS 7.01.7 & 7.01.8 - glennmcc, 10.10.2023, 21:35
  • New version DRDOS 7.01.7 & 7.01.8 - boeckmann, 12.12.2023, 17:04
    • New version DRDOS 7.01.7 & 7.01.8 - ecm, 12.12.2023, 18:47
      • New version DRDOS 7.01.7 & 7.01.8 - boeckmann, 12.12.2023, 21:15
        • New version DRDOS 7.01.7 & 7.01.8 - boeckmann, 12.12.2023, 21:27
          • New version DRDOS 7.01.7 & 7.01.8 - CandyMan, 13.12.2023, 16:58
            • New version DRDOS 7.01.7 & 7.01.8 - boeckmann, 14.12.2023, 18:00
              • New version DRDOS 7.01.7 & 7.01.8 - ecm, 14.12.2023, 20:58
                • New version DRDOS 7.01.7 & 7.01.8 - boeckmann, 16.12.2023, 21:52
                  • New version DRDOS 7.01.7 & 7.01.8 - ecm, 30.12.2023, 14:27
                    • New version DRDOS 7.01.7 & 7.01.8 - boeckmann, 01.01.2024, 13:57