Hallo
Me and my guys are working to connect Oric (Pravetz 8D) to CGA/EGA monitor. We have success with EGA but have difficults wit CGA. My question is:
Can someone tell me the memory location that rules 50Hz or 60Hz is sinchro-impulses. Thanks in advance,
George
Memory location for sinchronization
There is no location.
The video chip does not have any register.
But you can change the frequency by having the video display read a byte of the screen that contains a "frequency change" attribute.
Your choice:
24,25 = TEXT 60hz
26,27 = TEXT 50hz
28,29 = HIRES 60hz
30,31 = HIRES 50hz
You can force to TEXT 60hz by doing that:
POKE #BFDF,24
You can force to HIRES 60hz by writing 28 or 29 instead of 24.
The video chip does not have any register.
But you can change the frequency by having the video display read a byte of the screen that contains a "frequency change" attribute.
Your choice:
24,25 = TEXT 60hz
26,27 = TEXT 50hz
28,29 = HIRES 60hz
30,31 = HIRES 50hz
You can force to TEXT 60hz by doing that:
POKE #BFDF,24
You can force to HIRES 60hz by writing 28 or 29 instead of 24.