20 Jul
2005
20 Jul
'05
2:05 a.m.
The two-board token ring card is simply an older revision.
One engineer at Apollo told me that the older board is slightly
faster.
Newer ATR boards have special hybrid modules that the older
board lacks. I'd heard that there is something about these modules
that effects the performance of the board at the ISA bus level
of the board.
I think at the register level the two boards are identical.
----- Original Message -----
From: "Jules Richardson" <julesrichardsonuk at yahoo.co.uk>
To: <cctalk at classiccmp.org>
Sent: Tuesday, July 19, 2005 12:02 PM
Subject: RE: Apollo stuff
On Wed, 2005-07-13 at 10:48 -0500, Director wrote:
I would love to see pictures of the ends of the
ATR cable. I have some
ATR
cards and we will be putting one on display soon but I have never seen a
cable or the wall box.
I'll see if I can grab a photo of the cable this weekend at the museum
if nobody can oblige before then...
At least one of our Apollos (either a 3000 or 3500) has a TR card in it
that consists of two PCBs fastened together, whereas the more typical
type is just a single full-length card. Whether there's anything special
about the dual board version I don't know.
In later versions of IBM token ring the wall
mounted box (MAU) did do
something, but in original IBM TR it was strictly passive.
Ahh, that was what really prompted me to ask about the wall boxes - I
worked for a software company for several years who favoured IBM TR over
Ethernet, and recalled things not being as simple as just joining
machines together as there was a rack of IBM electronics in the corner
of each room. From what others have said about Apollo TR though it
really is simple and the wall boxes are purely for cable routing.
cheers
Jules