RE: What doesn't work: greyscale in software :-)

If black/grey/white is sufficient, you could use two or three screen buffers and switch between them on alternate scans by changing the video page latch.

>Try tying it to the STATREG register to get the vertical refresh irq
>edge transition and then use exactly coded opcodes to bit bang the
>contrast output.
>
>Look at the serial number decode in the room source.
>
>>-------- Original message --------
>>From: Tom Stepleton <stepleton_at_email.domain.hidden>
>>I was not able achieve a useful greyscale effect on the
>>Lisa's display by changing the values in the video contrast register
>>as fast as I could.
>>
>>It would be interesting to hear from knowledgeable folks if they
>>think I'm wrong in concluding that changing the beam intensity
>>"mid-flight" is not really possible.

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