RE: GEM and memory protection

["Howard Chu" <chu@platinum.com>]

> -----Original Message-----
> From: Eon Man [mailto:eonicman@erols.com]
> Jesús Cea Avión wrote:
>
> > > (extra question: how long does it take to make a RAM DUMP onto a
> > > harddrive file?, let's say 4 meg to dump).
> >
> > Using a SCSI drive, perhaps 4-6 seconds :). Less if you have a new
> > device and wide scsi :).
>
> What if you add in DSP or 68882 assisted compression?

The 68882 is no help since lossless compression algorithms are
inherently integer-based. Remember, this coprocessor is a Floating Point
Unit.
It is actually expensive in cycles for the FPU to perform integer arithmetic
operations because all the ints must be converted to floating point format
internally before the operation, then back to int afterward.

The DSP cannot drastically improve things since you communicate with it
via a serial bus clocked at around 1 MB per second.

Wide SCSI would also require a new SCSI controller somewhere on the
motherboard.
As I recall, the TT SCSI controller maxes out around 4 MB/sec, and Falcon
maybe
around 2.5? (Feel free to correct these figures...) ACSI maxes out at 1
MB/sec.

Despite the nice goodies included in the Falcon, it really is not a very
high-performance system. The TT is still the best 680x0 machine design
Atari ever built.