Hi guys, many thanks, my code with interrupts off and correct vsync (and after "no beer" review ) works as expected!

Thanks, I have found this great side too. Surprisingly the following code:

helped to run the code above smoothly using Qemulator, however my problem with the real QL remains as it was (the sync does not work).

Entering super mode with trap #0, as I understand. But I cannot find a code snippet to switch off interrupts. Can you help me?

To get a 100% stable sync with the display, you need to enter supervisor mode and switch off interrupts - otherwise, the toggling of the timer interrupt bit in the interrupt register will cause QDOS to enter the scheduler before it even runs the loop, with all sorts of things happening that could o...

Hi Tobias, many thanks for your fast and great response! However my problem still remains. In Qemulator my code works, using a real QL the sync does not (it flickers as it would be without the sync). Here my code example: SCREEN equ $20000 PC_INTR equ $18021 repeat lea sinus,a5 lea SCREEN,a6 loop mo...

For my small assembler demo "bouncing lines" I need a Vsync or similar functionality to slow down the loop and get stable redraw of the screen. I tried the described solution brought by https://www.chibiakumas.com/68000/sinclairql.php: waitVBlank move.b #%11111111,$18021 ;Clear interrupt b...

Could someone please, from the QL design team or similar explain this "crazy" idea for the design of the QL's screen memory... lea $20000,a0 move.w #%0000000000000001,(a0)+ ;one point blue move.w #%0000000000000010,(a0)+ ;one point red move.w #%0000000000000011,(a0)+ ;one point magenta mov...

Many thanks tofro. The hint with resistors did the trick. Additionally I have just found this tremendous site about QL's motherboards: http://www.sinclairql.net/build_standards.html

I have six QLs and just wanted to categorize them.

How can I recognize the revision of a motherboard without dismounting micodrives to flip the board (I've seen revision once on the backside of the board).

Thank you for the info about this trap. I changed the code to set 8 colors mode to the following and it works as expected! moveq #$10,d0 ;MT.DMODE Set or read the display mode moveq #$8,d1 ;d1.b key, 1:read mode -> d1.b display mode, 0:mode is 4 colour, 8:mode is 8 colour ;d2.b key, 1:read mode -> d...