On Mar 19, 2012, at 12:08 PM, Ethan Dicks wrote:
On Mon, Mar 19, 2012 at 11:37 AM, David Riley
<fraveydank at gmail.com> wrote:
On Mar 19, 2012, at 12:33 AM, Ethan Dicks wrote:
I thought it had a very tiny FIFO on receive (maybe 2 or 3 deep?). I'm
pretty sure the "enhanced" SCCs (85230 and up) had larger buffers.
I think the 85230 does. I don't remember there being any sort of SILO
in the 8530, but there may have been a latching register so you could
drop in "the next byte" while the old byte was still going out. I'm
not positive it has that, but I'm reasonably certain that it has
nothing more sophisticated than that.
Ah, looking through the 85C30 data sheet, it contains several *status*
FIFOs, but apparently none for data. Must have dreamed that (or
conflated it with the ESCC).
- Real Z8530s
(or second-source replicas)
- Real AM85C30s
- An AMD 85C80 (an unholy hybrid of an AM85C30 and a 53C80 SCSI
controller; I have some in my various LCs)
That looks like a fun one. There are places I would have liked to see
that in the late 80s/early 90s.
Apparently, that's what Apple thought as well. I've never seen them
anywhere else, but they certainly would have been handy in various high-
nd micros and minis of the day. Around the time of the late 68030
machines and most of the 68040s, they moved SCSI to the 83C90 and
83C94/96, which offered substantially improved SCSI performance due to
protocol offload. I think it's only the LCII which has the 83C80.
- Dave