Screen updating erratic after *screensave via dma

Screen updating erratic after *screensave via dma

Post by R.W.Darlingt » Wed, 12 Nov 1997 04:00:00



I have A StrongARM RPC running RO3.72 with a Storm 32bit DMA SCSI card
and have observed erratic behaviour after issuing a *screensave within
a non-wimp BASIC program.

Updating of the screen after issuing a *screensave becomes erratic, and
sometimes never fully completes, leaving bits missing here and there.

Does anyone else experience this problem, either with this SCSI card,
or with any other SCSI card that uses the dma manager?

Someone guesses that it leaves the screen memory un-cacheable
afterwards. Does anyone know of a command I could issue after a
*screensave command that would restore cacheability to the screen
memory and fix this strange problem?

Many thanks in advance.
Yours, Roger


 
 
 

Screen updating erratic after *screensave via dma

Post by Mr. Alan Angu » Sat, 15 Nov 1997 04:00:00




> I have A StrongARM RPC running RO3.72 with a Storm 32bit DMA SCSI card
> and have observed erratic behaviour after issuing a *screensave within
> a non-wimp BASIC program.

> Yours, Roger



I get the same behaviour with my Cumana SCSI card. If I save the screen to
the IDE hard disc there is no problem, so I tend to do this then transfer
the images to an SCSI hard drive when I have finished.

Alan Angus

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1. Screen Updating very slow after *screensave via dma

go to the task manager and wiggle the screen memory bar a bit.  That forces the wimp to reflag
the screen memory as non-cachable & non-bufferable.  If you load up a large sprite file (say
few thousand by 500) into paint time how long it takes to scroll from end to end by holding
down the horizonal scroll bars in a 16bpp or 32bpp mode with the screen memory cachable &
bufferable and
with it set nrmally, you will be suprised!

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RobT
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