IBM PC Network

Grant Taylor cctalk at
Sun May 23 00:31:28 CDT 2021

On 5/22/21 7:12 PM, Jim Brain via cctalk wrote:
> I guess that's a selling point of TR, but I loathed it when introduced 
> to it after using Ethernet at UIUC.  Having to learn CPI-C, LU-2, 
> LU-6.2, APPC, etc. and configure Communications Manager/2 on OS/2 to 
> emulate a FEP (3174?, not sure, my mind tended to bury such information, 
> and in fact I'm not sure if that's what it did or if it connected to a 
> FEP, that info is gone and I've no desire to go review it).

Given the things that I play with, I'd like to know more.  But I suspect 
that this isn't the forum.

> When the network worked, it was fine, of course, but it seemed every 
> week someone would do something that would switch a TR card in a PC to 
> 4Mb, and the entire network would die, "beaconing" for an hour while the 
> IT folks ran around trying to figure out where the issue lie.  And, it 
> was an office building, so not a ton of noise...

My first post high school computer job was help desk support for my 
local city government.  There were 500 or more computers and many of 
them were on Token Ring.  --  The migration to Ethernet was under way. 
--  The way that the network team dealt with beaconing was 1) multiple 
independent rings, and 2) disconnecting wings / floors of buildings to 
quickly isolate things.  It's entirely different to have a total network 
failure vs a floor / wing that can't use the network.

> Seeing the 370 (3090, as I recall, nice imposing looking machine) was 
> impressive, and I will admit working in a firm with an IBM 370 
> architecture machine gave me a new and profound appreciation for the 
> staying power of the mainframe (I started the job thinking, as all 
> recently minted IT professionals no doubt think, that the mainframe was 
> soon to be discarded in favor of UNIX and potentially the newly arrived 
> Linux OS. That job changed my mind).


I've got more of an affinity for mainframes than many friends.  One of 
the things I play with -- which I was eluding to above -- is an IBM 
P/390-E.  So I've spent some time with CM/2, MPTS, and the likes.  I've 
currently got my P/390-E working via TCP/IP over 802.2 LLC/SNAP via a 
virtual OS/2 Warp 4 system routing to TCP/IP over Ethernet II.  --  Your 
first statement really did trigger a lot of things in the realm that I 
play in.

> But, I never grew fond of TR, and as soon as IBM supported Ethernet, I 
> was happy. (Plus, there was no TR driver in Linux initially, and we all 
> desperately wanted to run Linux on our PCs to run a real OS instead of 
> Win3.1 or OS/2. OS/2 was nice, to be fair, but it was not UNIX...)

~chuckle~  I started my Linux networking on 10Base2 and PPP back in the 
2.0 days.  I don't know when Token Ring was added to the Linux kernel. 
It was removed in the early 5.4, I think.  --  Sadly, I don't think that 
Linux can be the multi-network router that I want.  I suspect that honor 
is going to go to NetWare 4.x or maybe 5.x.

Grant. . . .
unix || die

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