25th Anniversary of the Personal Computer" 4208

another from long ago and far away in the evolution into 2-tier-3-tier

re: 4341 vs. 3033 question; There is an Micro Design System (MDS) group that provides services to GPD engineers on an MVS 3033 (it is an almost self contained environment). They have just about converted MDS to run under CMS. The plan is to offer MDS service on several distributed VM-4341s connected to a MVS via the network. The central machine would still be used to maintain the (very large) data base on MSS. Individuals would "check-out" source from the central library (that logically happens today so the additions have to be the network routing), operate on it for several hours-days, and then return it to the central site. Project was justified for several reasons.

1) multiple 4341s to provide same level of service as one 3033 is cheaper.

2) desire to go to a distributed computing. Project demand for MDS thru 1985 is larger than any conceivable no. of 3033s, 168s, etc. that GPD would be able to acquire (not to mention the housing problem).

3) Total people & project costs when the current central 3033 went down justified multiple "front-end" machines. Users that had their programs already checked out would be able to continue working.

4. GPD has just completed a TSO interactive user study. The results very closely follows a number of earlier reports on VM from YKT. Any system response in excess of at least .5 seconds (YKT has been able to measure it down to somewhere in the area of .25-.30 seconds) there is a degradation in people response. Non-immediate system response appears to upset people's thought processes in some way. Any slow down in system response is matched by an equivalent slow done in human response (total slowdown in productivity is twice the system degradation). The same effect was measured in comparing local 327x performance with remote 327x performance. Moving the 4341s out to the engineers allows many remote 327x terminals to be replaced by local 327x terminals.

... snip ...

part of the above was with respect to TSO not being able to practically achieve sub-second response. The 4341-3033 comparison was relatively easily being able to acquire collections of 4341 that would provide more aggregate throughput than 3033 (at lower cost).

some number of locations would scavenge departmental supply rooms and-or conference rooms for deploying 4341s.

misc. past posts mentioning 4341-3033 comparisons: