[Rpcemu] Thoughts on RPCemu development
eda at waniasset.com
Mon Sep 3 12:02:04 BST 2007
>>There was the G8 from State Machine or
>>something like that, a more upmarket rival to the ColourCard, which
>>required special software to use the whole megabyte of VRAM.
>>It does appear that 480K is a hard limit.
>I've just had a look at the ModeExtension service (having just
>coded a module for 800x600x256), and I think there's a way
>around this for an emulator. You can change the screen address
>used by the VDU drivers,
Is this another couple of parameters in the big hairy structure you have to create to define your new video mode?
>I suspect what the G8 did was map video RAM in podule space
>(16k at a time) and the special software paged this around as
>VDU calls required.
According to <http://acorn.chriswhy.co.uk/docs/StateMachine/G8_User_Guide.pdf> the 'G8 Professional' card had a megabyte of VRAM but could not use it in the RISC OS desktop. So I suspect they weren't bothering to trick or redirect VDU calls but had their own graphics API (for which no software was ever written).
Ed Avis <eda at waniasset.com>
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