Re: about accelerator chips/cards

[damage_x@hotmail.com]

MagerValp wrote:
> >>>>> "dx" == damage x <damage_x@hotmail.com> writes:
>
> dx> The 65816 upgrades for the C=64 simply run at 1MHz in the old 64K
> dx> address space and run at 20MHz when working above 64K.
>
> No, they don't. The SuperCPU runs at full speed from local SRAM with
> mirrored writes through a 1-byte fifo to the internal C64 RAM and
I/O.
> RAM reads are always at full speed, mirrored RAM writes are stalled
if
> you write more than one byte per 1 MHz cycle, and I/O is always
synced
> to the internal bus, and even slowed down for some peripherals (e.g.
> 6526 CIAs don't like more than one access per every 4 cycles).
>

Oh OK, thanks for the info. A C64 guy tried to explain the SuperCPU to
me but I guess was missing some important details.

I recognize your name from the C-One list, do you read a lot of the old
computer NGs, MagerValp?

> --
>     ___          .     .  .         .       . +  .         .      o

>   _|___|_   +   .  +     .     +         .  Per Olofsson,
arkadspelare
>     o-o    .      .     .   o         +
MagerValp@cling.gu.se
>      -       +            +    .
http://www.cling.gu.se/~cl3polof/