🚀 go-pugleaf

One nasty problem with using a 16 bit microprocessor is making it
talk to 8 bit peripherals, especially using DMA. Most 32 bit processors
(like the 532) have dynamic bus sizing that solves the problem for you;
however, the 68000, 32CG160, etc. don't give you any help at all.

So here's a thought: is it totally warped to provide a section of 8 bit
memory on a board specifically for use with I/O devices? The idea is that 
both memory and I/O devices would be on, say, the low order byte of a
word, so that fly-by transfers in 16 bit mode copy the data from the
peripheral to the low byte of memory, or vice versa. For something like
the pc532 floppy disk controller card, this seems fine; the controller won't
really be looking at the data anyway, it just (for instance) reads it off the
floppy and then shoots it back to the 532 across the SCSI bus. 

Is this a total kludge? It certainly simplifies the I/O design.

-- Jerry "warped thinking a specialty" Callen
   jcallen@encore.com