Post by Lew PitcherPost by Lew PitcherLong ago, I was told (or I read) about an early business computer
(I'm guessing circa 1960) that the manufacturer sold in two
different clock speeds. If you bought the "slower" system, you
could pay a licence fee and have a CSR come to /remove/ a component
that /limited/ the CPU speed.
The Univac 9300, introduced in 1965, was their answer to the IBM 360/20.
Its 16-bit memory addressing was almost but not exactly unlike that of
the 360/20, but it executed instructions at the speed of a 360/30
(for the limited subset of instructions that it supported).
To cater to the low end of the market, they also released the 9200,
a de-rated version of the 9300. Some changes were physical: the
printer ran at only 250 lpm as opposed to the 9300's 600 lpm because
it only had half as many hammers and needed two passes of the print
bar to generate a line of print. But other changes were electronic.
The 9300's memory had a cycle time of 600 nanoseconds. The 9200
inserted a rest cycle between each active memory cycle, increasing
the effective cycle time to 1200 nanoseconds. However, there was
a switch inside labeled "Test mode D"; if you threw it those rest
cycles were eliminated and the CPU would run at full speed.
However, it also disabled parity checking, so you used it at
your own risk. The slower cycle time did allow the use of
marginal memory that wouldn't work in a 9300. You couldn't
do this if you attached disks to the machine, since the disk
channel had to magically speed up the memory to keep up with
the data flowing to and from the disk.
Post by Lew PitcherApparently, it is becoming standard practice again. But, this time
in the field of consumer goods.
I asked about the rumour because I just finished reading an article
(https://www.techdirt.com/2023/05/05/mercedes-locks-better-ev-engine-performance-behind-annoying-subscription-paywalls)
about Mercedes planning to put "better engine performance" of their
EVs behind a subscription paywall.
You buy the car. If you want better engine performance, you pay
a subscription, and they /disable/ the "poorer engine performance"
component. In other words, the car that you purchased /already/ has
"better engine performance", and you pay a monthly ransom to get it
enabled.
The analogy struck me as apropos.
I heard recently that if you want to activate the heated seats
in a new BMW you have to sign up for a subscription.
--
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