7 Jun
2014
7 Jun
'14
1:08 p.m.
On Fri, Jun 6, 2014 at 3:53 PM, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
Everything I have read (books and web pages) says that RS423 is
single-ended. The Macc had differental data lines. The Mac seems
therefore to be RS422 data lines and RS423 handshake lines.
FWIW, 'Designing Cards nad Drivers for the Macintosh Family' (I may have
slightly mis-rememebred that title) calls them RS422 ports. Which they
also aren't
Was there anythign abotu the early-ish Macs (up
to the Mac II series at
least) that was anything like stanard? The serial ports (both the
origianl D9s and the 8 pin mini-DIN were not any standard interface (they
were not RS422 ro RS423 as far as I can tell).
They were RS423. Mac Nubus is not
Again siad books sais 'Based on TI's Nubus' (or somehtign simialr) which
implies to me it is not pure Nubus. The book, alas doesn';t give the
differences other htan the trivial ones (limitation on the size of the
PCB, no -5.2V supply). And yes, it is certainyl close enough to the TI
spec that hte standard ICs will work.
I thought, but can't find the details, I read somewhere tht there was one
fairly obscure thing that Apple did differently and which meant it wasn;t
strictly Nubus. If I come acorss the detials I'll post them.
-tony
stnadard Nubus (UI have read the specs for both).
and so on.
Really? What did Apple do differently? It was close enough that the TI
Nubus interface chips worked fine.