David L. Beem
2004-08-16 02:05:02 UTC
from different manufacturers that did a good deal of the work to
interface to the microchannel bus. With the development of at least
one new microchannel adapter being considered we need as much data as
possible. Although I see some of these parts still in surplus
inventory, many of the manufacturers have of course purged them by
Louis did two topics covering a selection of the chips on a
single day back five years ago. There were no (public) replies, which
is disheartening. Hopefully there is more interest now (but harder to
find the parts) for MCA development nowadays on the newsgroup. I will
provide some examples of the adapters that use particular interface
chips & anyone is certainly welcome to respond about an adapter I
don't know of.
Ideally would be datasheets or other information on how the chips
work. The ADFs themselves can provide many clues. I'm leading in with
a chip I only have found on one real adapter, without an ADF (at least
for what I now find): The recent topic of the Seattle Telecom & Data
PSX/386/486 I have posted about.
A search tonight revealed a document by National Semiconductors
for an adapter they apparently registered, but never developed. It
also uses a Chips & Technologies 82C611 (beware of webpages covering
the Opti 82C611, which is a VLB IDE interface chip wholy unrelated to
our needs) & reveals a great deal about how the chip operates. For
those of you interested, the document now resides at
Another publication I am looking for is "CHIPS 82C611, 82C612
Micro CHIPS: Micro Channel Interface Parts (1988)". From what I
remember "C&T" has now gone out of business or been absorbed into
another company (Intel?). As you can see in the title, there is a
small chip line from C&T, with the 82C611 somewhat at the low-end.
The next post will cover the C&T 82C612, which is on at least two
adapters I have found. After that it is on to the 82C614 (but I
haven't found any adapters that use it) & the apparently older C&T
82C574 & 82C575 that I have found on a couple of adapters apiece.
Other manufacturers come later.
Read up on the National Semicondutor document; I'm going to snip
some information from it for successive posts on this thread. The
pinouts of the 82C611 in the NS implementation will be compared to
what I show with a voltmeter on the PSX card. If I don't find an ADF
for the PSX card then I very well may have to try writing one, with
the National Semiconductor paper as my only example of an ADF for the
So the C&T 82C611 is used on the following adapters:
STD PSX/386/486, Adapter ID 003Ah, No ADF found
NS Dual UART adapter, Adapter ID 6E6Dh, No adapter manufactured?
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