With all the inisde the house time I decided to revisit my Z280 board to see if I could finally get some real use out of it. After some fiddling with the Z280 configuration registers I can finally use it to boot into MSX1, MSX2 and MSX2+ on my DIY MSX (Z8TY)!
Basically all the advanced Z280 features like caching have to be disabled to make it work for MSX.
I/O operations like accessing the VDP have to be really slowed down otherwise there is corruption or nothing on the screen at all. Using VDPWAIT helps but is not always enough.
Now to see if I make it work with higher frequency clocks, I probably have to add extra hw to slow down I/O port access. Using the internal configurable I/O waits (up to 3) is not enough (at least for the VDP).
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