23 Dec
2013
23 Dec
'13
11:04 a.m.
On Mon, Dec 23, 2013 at 01:05:44PM -0500, Ethan Dicks wrote:
[...]
My first several SCSI interfaces for the Amiga were
PIO and could only
transfer a couple hundred Kbytes/sec. I knew how they worked from my time
writing embedded 68000 code with transfer loops and was not surprised at
their speed.
If you had contrived the hardware design to have suitable incomplete decoding,
you could have exploited the movem hack that copies 56 bytes in 72 cycles,
which would give you north of 5MB/s on a 7.09MHz CPU.