Hello world on V9990

Page 2/2
1 |

Par Grauw

Ascended (8734)

Portrait de Grauw

31-12-2019, 01:49

Metalion wrote:

Is there something special about the interruptions and the v9990 ?

No.

Metalion wrote:

It is sending the value 7 to the interrupt port (66h) at every interruption. Do I have to do that ?

If you enable V9990 interrupts (register 9), you need to acknowledge them, otherwise the /IRQ signal stays low, it gets stuck in an infinite interrupt loop and your program will hang. Probably for your initial tests you can keep the V9990 interrupts disabled, but eventually you will want them for vsync and that sweet command completion interrupt that I wish the V9938 had.

Par Metalion

Paragon (1101)

Portrait de Metalion

31-12-2019, 12:44

Allright ... I'm getting there.
"Hello world" on v9990 done (P1 mode) !

Page 2/2
1 |