I built the ZX80 from Grant´s web site, including NMI ,slow generator and 16k SRAM upgrade
All programs loaded works well, like 3dmaze,Manic M (pseudo hires) and others.
But after loading the "FullHDzeddy¨ demo i noticed that Hires is not working using the original configuration
I did some tests and changes , adding /RFSH signal and removing /RD from /OE and it "started" working but not OK yet.
Attached some pictures of the problem.
Do you have some idea or suggestion about how to fix this issue?
There is a small blank period on the screen.. Only in this portion the picture is displayed correctly..
It is weird.. On the ZX81 , theoretically, /RFSH is not necessary..
![Rolling Eyes :roll:](./images/smilies/icon_rolleyes.gif)
Even the 1K WRX1K demo only work after this RFSH modification.
Maybe using a different slow circuit?
Any ideas are very welcome!!
Thank a lot again!
![Wink ;)](./images/smilies/icon_e_wink.gif)
Regards
Luciano.