Hi Everyone,
It seems that the modifications i'm making to the NMS8250 all fail somehow. After spending a long on getting the V9958 to work, i now have started to make the system a MSX 2+.
Bought a set om 3 roms from Bas Kornalijnslijper, read his documentation and watched his video. In the video tests the V9958 first, then the roms and then the LS chips.
The V9958 is working, but after the Rom mods i'm getting a black screen and that's it. Placed the old Roms back and desoldered the connection on the MY connector and everything works fine again.
So what could this be?
Faulty Roms? I've dumped the roms before making the modification, but i can't find them on the internet to verify if they are any good.
Wrong Connection? In the documentation there has to be a connection between the MY connector pin 38 and IC117, but in the video Bas said it should be Rom B (IC118). When i look at his work in the video i can see the wire is connected to IC117 so i guess it should be IC117.
I have done dozens of mods in the past, but i never had more trouble than with his MSX 2+ upgrade
Is there anybody who can give me some ideas where to check?