1 Feb
2022
1 Feb
'22
12:45 a.m.
On 1/31/22 6:26 PM, Thomas DeBellis wrote:
That point about CPU usage really was /the/ point. I
think I remember
an IBM 3033 demonstration system with some absurd number of 3270's on
it; I mean something like 11,000. No way you could that with full
duplex; too many Start I/O's. Even if you did a Start I/O no-release,
you just would never had the gas.
Very much so.
All things being equal, the deals we could get on a
3270 were about
twice as expensive as what we could get for a HP2621 or something of
that caliber.
That's pure typical IBM-overpricedness and nothing more. The
electronics are no more complex (in many cases, it's less complex) than
character-mode ASCII terminals.
The wiring was more expensive to do. What I remember
is
our com guys complaining about the coax being difficult to work with
while RS232 being nowhere as difficult and the wire itself costing less
(not sure about plenum grade).
Even plenum-grade multiconductor non-coaxial cable is cheaper than
coax. IBM could've used 50-ohm coax which would've given them access to
RG-174 cable, which is ~1/8" diameter and very "soft", and it wouldn't
have cost them much in the distance capabilities, but they chose not to
do so.
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA