14 Apr
2005
14 Apr
'05
4:49 p.m.
On Thu, 14 Apr 2005 01:23:03 -0400 (EDT)
der Mouse <mouse at rodents.montreal.qc.ca> wrote:
The 8530 is a useful part for dedicated purposes,
but isn't it
severely bandwidth cramped?
I don't think so, not per se.
Yes. My wording was crude and unclear. I also have multiple IPC's,
IPX's and an LX. I think the LX is the one I consider the best of the
form-factor.
I guess my comment was incorrect in that I was speaking of how the chip
functions in Sun hardware, as above. I suspect the chip can 'scream' if
fed the right clock.
I'm also prejudiced because a few years back I worked in a team on a
Intel 80296 based telemetry project that included an 8530 in the design.
I never had to touch that code, but one of the guys who did absolutely
despised the 8530. I took the liberty of handing him a copy of the
NetBSD code for the chip, which I think helped him understand it a
little better. If I'm not wrong (from my cursory glance over the
datasheet) it's a very stateful part that the programmer has to be well
versed in the care and feeding of. I probably WOULD be better
acquainted with the chip, but the tube of 8530's that I once purchased
on eBay, AND paid for, were never delivered by the seller. heh.
(not gonna
wire two 6402 UARTS to my SYM-1 and [...])
How about one Z8530? :-) [it's a
DUART, for the Zilog-impaired] I am thinking that it's the serial chip in
the Sparcstations,
correct me if I'm wrong.
No, that's right as far as it goes - most SPARCstations, at least.
A few years ago I was pondering making a
'dialup connecting system
with NAT server' out of a SparcStation Classic (the little lunchbox
type Sparc).
Well, _one_ of the lunchbox SPARCs. (The others are the IPC, the IPX,
and the LX.)
I discovered
quickly that the serial ports on the Sparc are VERY
speed constrained because of the 8530 chip. It would have been
impossible to connect my USB Courier V-everything modem to it at,
say 57,600 baud, because the 8530 just plain won't go that fast.
While this is true of the 8530 *as used in the SPARCstations*, this is
largely because of the clock Sun chose to drive it with. Use a faster
clock and your baud rate cap goes up correspondingly. (Presumably
there is a limit on the clock rate, but I don't know what it is; I'm
fairly sure it's well above what Sun uses, at least.)