Re: Help with Homemade ZX80-81- HIRES problem
Posted: Sat Nov 25, 2017 2:42 pm
Yes - or something like that.
I had that in my mind that it is wrong (and unnecessary) to use /MREQ for character map fetch but was too lazy to research why.
Anyway the ZX80 video part is different to ZX81 and here the shift register is loaded definitely on the beginning of the (next) /M1 cycle or better rising edge of T1. This has still active refresh signal from previous /M1 but /MREQ is long gone (half clock cycle or 150ns).
- Bildschirmfoto 2017-11-25 um 14.42.33.png (30.57 KiB) Viewed 1320 times
