On 02/18/2013 05:36 AM, Shmuel Metz (Seymour J.) wrote:
In <201302151911.49741.jlturr...@centurytel.net>, on 02/15/2013
at 07:11 PM, Leslie Turriff <jlturr...@centurytel.net> said:
Not so much a mistake as short-sightedness; before 3270s were
available, keypunches could only do upper-case
In the same time frame IBM had software that supported dual case
using, e.g., 1050, 2740, 2741. I suspect that moncase had more to do
with corporate culture than hardware.
Having a few devices that supported dual case didn't necessarily make it
economically reasonable to adopt dual case. There was considerable
(more than a decade) overlap between use of card equipment and the
deployment of 3270 devices, and as already remarked, card punches didn't
support dual case, nor did the original 3277 model of 3270 in 1971. It
took another 8 or 9 years after introduction of the 3277 before the
first 3278 terminals with full dual case support became available and
much longer before all 3277's were phased out. There was a strong
economic motivation for the lowest common capability to determine local
standards. Our data center didn't totally phase out the use of cards
until sometime after 1985, after conversion to MVS, and line printers
with higher dual-case costs persisted for decades after that.
I'm not sure how early one could get dual case support for line
printers, but the most common high-speed production print technology
pretty much through the end of the 20th century were line printers with
print bands or print trains, and using dual-case bands or trains reduced
the number of repeated patterns and effectively cut print speed in half,
doubling the hardware cost of printing dual case. Laser printers like
the IBM 3800 which didn't have this problem were available from the late
1970's, but they were very expensive and supported the print volume of
5-10 line printers -- you had to have an incredibly high print volume or
an application that absolutely demanded that print flexibility to cost
justify two of them (so you could continue production when one was down
for extended maintenance).
Now that relatively cheap slower laser printers with multi-font support
are ubiquitous, print band line printers are on the decline,
application development and data entry are no longer tied to punched
cards, and mono-case display terminals are long gone, dual-case support
is almost no-cost. That was not the case for decades, and corporate
culture (in the companies that are still in business) did tend to frown
on expenditures that were deemed avoidable and which could not be cost
justified.
Existence of millions of lines of program source written with mono-case
conventions may continue to influence local coding standards, but at
least the hardware cost penalty of dual case is no longer an overriding
factor.
Many of the early choices in computing which don't make sense to the
latest generation were simply driven by the economic realities of the time.
--
Joel C. Ewing, Bentonville, AR jcew...@acm.org
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