Date   : Thu, 23 Apr 2009 22:03:26 +0200
From   : kortink@... (John Kortink)
Subject: ARM7 CoPro Demo Stuff

On Thu, 23 Apr 2009 20:11:33 +0100, "Rob Coleman"
<rgcolem.myorg@...> wrote:

>[...]
>
>Also, the New Advanced User Guide has a routine that takes a block of memory 
>from the parasite and writes it to the host's screen memory. With a small 
>enough window on the host, it might be possible to get a reasonable 
>animation running.
>
>[On a technical  note, is the Arm7 Co-pro bound by the same data transfer 
>timing constraints as the original units that use the TUBE ULA or can it 
>transfer at higher rates?]

It can basically transfer at top speed, e.g. with GoMMC
configured to 'warp' mode (which is almost back-to-back
byte writes, around 150 KB/sec, 200 potentially with a
slight rewrite of a bit of (generated) code.

But it's not completely reliable (at least not on my
ARM copros). It is reliable on my remake of the 6502
Second Processor when it runs at 14 MHz, so there may
be a slight performance or timing problem on the ARM
CoPro side.

Of course, drawing from (Go)MMC straight to screen is
equally fast, and not limited to just 16 MB ... ;-)


John Kortink

-- 

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