] Hi!
]
] This message is intended for VDP-aholics and emulator programmers. I am
] examining the V9938 timing details to help Marat improve fMSX. I discovered
] some things about the line interrupt I never heard about before.
Hi Maarten,
One year ago (on 9 dec 1999, subject 'Re: SCREEN7/8
On Sat, 23 Sep 2000, you wrote:
*** About the horizontal interrupt
All relevant definitions on a row:
-FH: Bit 0 of status register 1
-IE1: Bit 4 of mode register 0
-IL: Line number in mode register 19
-DL: The line that the VDP is going to display (corrected for vertical
scroll) -IRQ:
On Sat, 23 Sep 2000, I wrote:
Anyway, I'll program the following test tonight:
1. set line interrupt to line 100 (any line is OK)
2. enable line interrupt (IE1:=1)
In the interrupt handler:
3. poll until start of line (using HR)
4. disable line interrupt (IE1:=0)
5. read FH (status
Hi!
This message is intended for VDP-aholics and emulator programmers. I am
examining the V9938 timing details to help Marat improve fMSX. I discovered
some things about the line interrupt I never heard about before.
I did two measurements that contradicted each other:
First, some
