25th Anniversary of the Personal Computer" 4207

part of the early migration to c-s and then to 3-tier ... was moving out of the terminal emulation paradigm. ibm-pcs started to see rapid uptake in business environments because a single desk footprint could both emulate mainframe terminal as well as provide some amount of local interactive computing.

we had been doing terminal emulation scripting using mainframe virtual terminal facility ... earlier with parasite-story ... first showed up about the same time as the early rex ...

some of the syntax was similar to rex ... but was completely different. old parasite-story terminal scripting ... a few old parasite-story postings:

for some time, there was period that view the components of 3-tier as independent ... this post mentioning project vis-a-vis personal computers ... as alternatives. there is such a discussion in this report about bell labs from the early 80s

from recent thread:

from above:

By far the most important influence on the development of Rexx was the availability of the IBM electronic network, called VNET. In 1979, more than three hundred of IBM's mainframe computers, mostly running the Virtual Machine-370 (VM) operating system, were linked by VNET. This store-and-forward network allowed very rapid exchange of messages (chat) and e-mail, and reliable distribution of software. It made it possible to design, develop, and distribute Rexx and its first implementation from one country (the UK) even though most of its users were five to eight time zones distant, in the USA.

... snip ...

i.e. and i've periodically noted that the internal network had nearly 1000 nodes at the time the arpanet-internet had approx. 250 nodes at the time of the great switch from arapnet to internworking protocol on 1-1-83

the attached email references some evolution of 2-tier operation ... just between "mainframes" ... i.e. typical glbutt house operation ... like HONE that had been providing world wide online interactive support to all field, marketing, and sales

... and the "project" or "departmental" 43xx machines that were starting to find their way into the branch offices.

To: wheeler

Hi Lynn,

I've just return from 10 glorious weeks in New York. I had the privilege of attending SRI. Now that I'm back in the trenches I am trying to get caught up on what's been happening in the real world. How did your HyperChannel setup work out? Seems to me that it could be a possible solution for a project I'm working on. If you have a few minutes give me a call or send a message with your ideas to the following:

We are trying to provide central maintenance for VM and VSE to the Customer Support Centers located in about 150 branch offices. Initially I have convinced 14 to work with me to develop the methodology to do so.

The CSCs have 4331 Model Group 2 with 4 meg and will run a VM-VSE environment most of the time if not always. Central maintenence will involve problem determination, PTF application, and component distribution.

The base systems will be generated here and distributed on tape but looking to the future we expect to provide electronic distribution.

My biggest concern is what facility to use for bulk data communications. So far I have agreement from Tampa to use the 56KB SNA backbone, and from SBS to use an undetermined bandwidth (all the cities I selected will have earth stations in the near future). Initially I will use existing 9600 bps lines. If I use conventional TP, I am limited to 56KB due to the 4331 ICA. If I can sell something like the HyperChannel I could take advantage of the satillite's higher speed (cost will be a definite issue).

In any case your ideas will be appreciated. If you think it would be beneficial to get together I can arrange that too. Be talking to you.

... snip ...

part of the reference in the above is that HSDT (high-speed data transport) project activity had already started ... using initially terrestrial T1 (and non-sna protocol) ... and then adding satellite T1 links (for a while, hsdt even had its own dedicated transponder on sbs4)

we even got to be VIPs at the 41D launch for SBS4

so what we started to see progressing (somewhat in parallel) was the proliferation of 2-tier operation between glbutt house and department-project computers ... and the evolution of terminal emulation PC operation into 2-tier (and client-server) operation.

the proliferation of these two, somewhat independent activities started to then to evolve and coalesce into early, internal 3-tier operations.

however, by the time we were started to make marketing presentations to customer executives on 3-tier ... the SAA effort was moving into full swing ... somewhat directed at trying to contain 2-tier, client-server ... and protect the existing terminal emulation install base as long as possible.