Apollo stuff

[Bob Shannon]

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
>
>
>