On The Drawing Board VS site planning considerations
From "VS Workshop",  Access 87, December 1987
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Recently, I have had a chance to participate in a few user group activities revolving around site planning and environmental concerns. This brought to mind the system installations I have had contact with, along with my present tasks related to our firm's relocation next year. This month I hope to relay some of these ideas in the hope that they may spur discussion and highlight potential areas of liability.

Yes, I am well aware of the ennui that sets in when the discussion turns to site preparation, security, or contingency planning; nonetheless, I think there is enough of interest within these topics to keep your interest. So stifle those yawns and DON'T TURN THAT PAGE!

Planning computer sites in the real world

If you are considering a new site or wish to considerably expand an existing one, you should begin with a plan. If this need seems obvious to you, keep in mind that most of the VS installations I know of have had little or no plans when implemented. Sure, there may be all kinds of plans at the origin of the project, but precious little of them survive to installation. A plan is NOT a requirement - unless you wish to recover gracefully when things fail.

The first step in the planning process might be to sit down and plan your needs, carefully considering your current needs for cooling, power, networking and the like. After that, you could factor in the expected growth of your organization and likely technological advancements. Finally, your analysis would turn to the level of your involvement in automation - the future role of machines in your organization. The final report would be chock-full of graphs, comparative analysis, and cost-benefit findings.

Not likely, huh? Those of us toiling on the minicomputer farm are rarely able to cut enough time to finish a day's work in a day and a half, let alone tackle a large feasibility study. Still, one can dream. . .

While you might indeed perform all of the analysis described above, a more likely scenario in the VS world might consist of preparing a scale floor plan showing the equipment already in use, followed by a quick pass through Wang's Customer Site Planning Guide (publication 700-5978F; no charge). Yes, Wang will attempt to steer you right by sending an analyst to review your plans, but these poor devils are under pressure to avoid risky behavior around an incomplete sale and are likely to accept whatever you come up with if it has any chance of working.

While I don't advocate scrimping on any part of the planning process, it is reasonable to expect that some compromises must be made. Experience leads me to suggest you direct your attention first to the items that can have the greatest impact and cost the most to fix later: power and air conditioning.

Your computer's diet: power and air

Most cooling and power requirements can be obtained from Wang or other equipment vendors. I advise that you treat these numbers suspiciously; it is too easy to fall into the belief that you can EXACTLY predict your needs from the back of a manual. Beware statements in product literature such as "designed for the office environment"; environmental factors can vary tremendously within any area, requiring different solutions.

Be sure to allow for the unplanned - extra equipment, additional people ("warm bodies") in the room, poor wall insulation. While it is true that real power and cooling needs for computing equipment are dropping, it is also true that demand for additional computing equipment typically outstrips organizational growth. Remember, replacing a insufficient air conditioner or power conditioner costs far more than allowing for growth at the outset.

Power planning shouldn't stop with surge protection and isolated circuits. Thought should also be given to the distribution of power within and without the computer room. Power distribution systems have made this easier by combining the power conditioning and distribution architecture into a single unit. Power distribution centers also cost less to install, since most electrical codes allow their installation without conduit.

Grounding is a special requirement. Electricians familiar with the needs of computing equipment speak with awe of the "art" of establishing a consistent, solid ground. To those of us in the lay world, a stick in the ground or a water pipe seems good enough, but the real task of getting a good ground is complicated by ground water considerations, nearby electrical activity, and many other subtle influences. Fortunately, the VS is a solid performer and will ignore most minor electrical interference. (Not so with mainframe equipment. At a recent user group, I heard about the extreme effects of minute changes in the ground plane on newer IBM systems.)

Peripheral connections

In the early (dark) ages of the VS, there was but one type of peripheral connection: through a large Centronics-type connector and thick cable containing a dozen or more pairs of wires. The parallel terminal (e.g. 2246P), though blindingly fast, died mercifully early in the life of the VS, and was replaced by dual coaxial cable and a proprietary synchronous connection.

Improvements in the number of terminals the VS could support resulted in rapid growth at many sites. This led to installations justly termed "snake pits": enormous bundles of cable spewing through walls and under raised floors, all arriving with infinite confusion at the rear of the CPU's backplane. Yea, many sites still face such conditions.

Fortunately, the times have changed.

Wang's first answer to the problems of workstation connectivity was to create Local Area Network (LAN) Peripheral Band components. This approach allowed the customer to use one radio-frequency cable to connect a large number of terminals and printers, thus saving on the enormous cost and effort of the so-called "home run" cabling approach. While the network cables are harder to string and must be left in their original lengths, they still represent one of the best ways to connect peripherals.

Since that time, four other major developments have taken place. First, Wang and third-party suppliers now sell coax-to-twisted-pair (CXTP) adapters that allow serial communications with printers and workstations using ordinary telephone wire and for distances of up to 600 feet. Second, Wang has made it possible to use asynchronous terminals, thus allowing us to use a variety of industry-standard multiplexers, short-haul modems, and the like. Third, Wang introduced the Cable Concentrator, an external cabinet that functions like the backplane of the CPU. Last, third-party vendors have made serial multiplexers available for the Wang marketplace.

While I don't intend to cover all aspects of workstation connectivity at this time (I will be covering that in a later column), I intend to leave you with the idea that there are many options for connecting your peripherals. I would most certainly recommend you consider using CXTPs and twisted-pair wiring; if you work in an old building and have a relatively new telephone system, you are safe in assuming you can use the extra wiring to connect to the VS. In any case, do consider all of the options when pondering a new site or expansion of an existing site.

Other considerations

From the many other possible considerations, here is a condensed list of items for your plan:

1. Access to Equipment: Are tape drives and disk drives with removable disks fully accessible to the operators? Do you have enough terminals? Do you need to secure this equipment from most users?

Careful attention should be given to the placement of peripherals requiring operator attention. The loss in operator productivity easily overruns the effort in getting it right.

As for system consoles, I recommend that you dedicate Workstation 0 to system messages, IPLs, and the like, and provide one or two additional windows for other tasks. Occasional data communications activity might require additional terminals, since most sessions are carried out interactively.

2. Documentation: Is there adequate space for a full set of manuals?

3. Dust: Again, the VS is (relatively) forgiving. The air conditioning system should exert enough force to provide a positive air pressure in the room, forcing dirt OUT whenever the doors are opened. If you are setting up a new site, specify dust-free suspended ceiling tiles and vapor-lock wallboard.

4. Storage of Backup Materials: This can be as informal as a few cabinets in the corner of the room, or as complex as hermetically-sealed storage lockers. Most VS sites opt for the simple approach, with daily storage near the computer room and off-site storage on a weekly basis. Storage in the computer room offers the advantage of a consistent temperature and lessens the chance for possible errors resulting from expansion or contraction of media. Be sure to keep disks or tapes secured from printer dust, sunlight, and magnetic energy.

5. Radio-frequency (RF) and electromagnetic interference: There are occasions when RF interference can wreak great trauma. Watch out for large motors or controllers in close proximity to system components, particularly the RF cables and Netmuxes of WangNet's Peripheral Band. In extreme cases it may be necessary to enclose the offending unit in metal to seal off the interference. Remember that power conditioners are giant magnets; don't store your tapes or disks on top!

Conclusion

Most data processing people will agree that they are the marshals of organizational change. Yet it is these same people that stubbornly refuse to acknowledge the inevitability of changes to the physical computing environment. The ultimate test of a site plan is NOT whether the installation is completed smoothly; rather, it's real test comes later, when unanticipated needs are recognized.

Who is available to do the planning for a site installation? While the mainframe world boasts many specialized site-planning businesses, the minicomputer market is still dormant. If you wish to hire some expert help and can't find a consultant you can trust, a good compromise is to find a sensible electrician with experience in computer or hospital wiring. Remember, though, that you must ultimately take responsibility for the site plan, its implementation, and its maintenance; few firms offer after-installation upkeep.

If I have provoked your thoughts, please write and share your comments. With interest from you, I hope to have a follow-up column and share some reader's experiences.