martinlindhe / dustbox-rs

DOS emulator (semi-abandoned)
https://martinlindhe.github.io/dustbox-rs/
MIT License
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CGA status register #18

Open martinlindhe opened 6 years ago

martinlindhe commented 6 years ago

The CGA status register (io port 0x03DA) should be implemented correctly.

Many demos check the status of the following bits to sync screen updates:

Bit 0 - horizontal retrace in progress
Bit 3 - in vertical retrace

Currently, we hack around this by changing the bits over time in https://github.com/martinlindhe/dustbox-rs/blob/master/src/cpu.rs#L3586