Not Getting Stable NTSC Video

  • Amiga model: 2000 rev 6.x + ACE2b Agnus, 28.63636MHz system
  • 680x0 CPU: 68030 50MHz (TF536)
  • RAM Configuration: 2MB ChipRAM + 64MB 32bit FastRAM
  • Kickstart, AmigaOS Versions: KS 47.102, OS 3.2.1
  • ZZ9000 Firmware version: 1.11 A500 4MB
  • ZZ9000 Driver version: 1.11
  • Monitor model: Dell 1905FP-B
  • Other Zorro cards: none

P96 software installed

RTG modes working
PAL modes working
OCS\ECS NTSC modes cause the display to blink on an off

(bonus observation)
If you turn the display brightness up, you can see it is blinking during the black screen portion of Workbench bootup as well.

I think I’ve got the right firmware, the right driver, the right Picasso version from iComp.
I’m ready to get started on the OCS\ECS NTSC modes working part.

Since I’d not heard back, I decided to do some more digging…
I found that the PAL video modes worked okay and the RTG modes worked okay, but as soon as my Amiga asked for NTSC, the screen just blinks. It’s possible to push an NTSC Agnus into PAL modes of course, but it’s not possible to prevent it from reverting to NTSC laced when you launch Sysinfo for instance.


I still hadn’t heard back, so I decided to experiment further.
I swapped my NTSC Agnus for a PAL Agnus and Crystal

And BAM!
Now the computer boots normal without the flashing screen.
Sysinfo works fine, since it chooses a high res PAL mode.

I still can’t use:
NTSC High Res laced
NTSC High Res
NTSC Low Res laced
NTSC Low Res
NTSC Super High Res
NTSC Super High Res Laced
Without the screen flashing on and off

At least now that I’m booting as a PAL machine, I’m not stuck in the flashing screens.

Can you please tell me what I must do to enable NTSC modes to work ?