IBM 3725 Communications Controller - test-drb@ccmp.vtda.org

14 Dec 2006

In the early '80s at ADP Network Services (old timesharing service), we 
connected a couple of IBM and compatible mainframes (IBM 4381, Amdahl 
470) to our packet switching network. It took our systems guys a bit of 
work, but indeed, they did connect the 3725 to a PDP-8... and from that, 
to the rest of the packet switching network. (The network was originally 
designed and optimized for PDP-10's, which coexisted with the blue 
boxes.) The IBM side ran under CICS. As I recall we eventually needed 4 
PDP-8's (as network bridges) to carry all of the traffic from the 2 IBM 
boxes-- supporting 400 or 500 simultaneous users. Ah, the old days... 
Brad Pritts (now strictly an end user!) (We had several hundred PDP-8's 
which we used as network nodes.) Eventua Message: 24 Date: Thu, 14 Dec 
2006 11:35:42 -0500 From: Sridhar Ayengar <ploopster at gmail.com> Subject: 
Re: IBM 3725 Communications Controller To: General Discussion: On-Topic 
and Off-Topic Posts <cctalk at classiccmp.org> Message-ID: 
<45817D5E.5000305 at gmail.com> Content-Type: text/plain; 
charset=ISO-8859-1; format=flowed Patrick Finnegan wrote:

...
    >>
Imagine this hooked up to a PDP8!  or an Imsai! now thats cookin.       

> The machines that this hooks to are a lot larger than the largest
> PDP-8.  8-)      

 There's no reason you couldn't hook this to, say, the P/370 that was just 
 on eBay (and had a bus and tag port).  That's smaller than even an 8/e.   

Except that (if memory serves) this kind of coprocessing communications 
aggregator would be able to pass more data than the P/370 has I/O bandwidth.

Anyway, I've seen many P/390 installations that are bigger than a PDP-8.

Peace...  Sridhar