DOS ain't dead

Sound (Users)

posted by Laaca , Czech republic, 30.07.2021, 22:21

Hm, it seems that the wrong implementation of VESA fn.4F07h (which is causing painfull slowness and flickering when changing the videopage) can by detected by software (i.e. not only by interractive test).
Thy to load standard VBETEST utility and select there interactive test.
Choose the videomode and refresh rate and run the interractive test.
The first test is drawing the colorfull pattern but the second one is the page flipping test.
If your function 4F07h is wrong, the counter will show the still the same videoplane. There will be some moving lines suggesting that there are some page switches but there will be still written PAGE 1.
If the BIOS and 4F07h function are OK, the page number will be still and fast changing from 0 to N.
So it means that the detection is possible (probably using INT 10H/AX=4707h/BL=01h)

---
DOS-u-akbar!

Complete thread:

• Sound - libz, 08.07.2021, 18:16
  • Sound - mceric, 08.07.2021, 22:35
    • Sound - RayeR, 09.07.2021, 15:55
      • Sound - Zyzzle, 10.07.2021, 01:13
        • Sound - RayeR, 13.07.2021, 02:24
          • Sound - Zyzzle, 20.07.2021, 02:02
            • Sound - Laaca, 20.07.2021, 10:58
              • Sound - Zyzzle, 20.07.2021, 15:34
              • Sound - Laaca, 30.07.2021, 22:21
            • Sound - RayeR, 20.07.2021, 16:48
              • Sound - RayeR, 30.07.2021, 21:03
                • Sound - Zyzzle, 31.07.2021, 00:38
                  • Sound - RayeR, 01.08.2021, 17:55
  • Sound - KormaX, 11.07.2021, 02:50
    • Sound - mceric, 11.07.2021, 12:27
      • Sound - KormaX, 11.07.2021, 14:10
        • Sound - Zyzzle, 12.07.2021, 05:15
        • Sound - dggionco, 12.07.2021, 17:19
        • Sound - RayeR, 13.07.2021, 02:15