On Sun, 09 Apr 2006 10:24:51 -0400, Dumbjaw <email@example.com> wrote:
>A few questions, though, none of which are answered on any of the
>clicky keyboard websites or Wikipedia.
>Alright, so you've got the classic, original models: 1390120, 1390131,
>1391401, 1391403, 1391406, 1391472, and 1391506. These are all using
>buckling spring (clicky) technology with a detachable SDL-to-AT/PS2
>cable and removable keys. They have the solid metal chassis underside
>construction and weigh about 5 pounds.
>Then you've got the next phase of models: 42H1292, 52G9700,
>82G2383,and 92G7453. These are completely identical to the originals
>as far as I can tell, except that some are made by Lexmark for IBM,
>the cables are exclusively PS/2 and not detachable, the IBM logo is
>blue instead of black, and they have drainage channels to help prevent
>liquid damage from spills.
>Now generally, the original models are more expensive when you find
>them. Is it because they actually have higher-quality construction
>than the ones with drainage channels, or is it just a retro thing that
>people fall for?
>It would seem to me that if I had a choice, I'd take the kind with the
>drainage channels. Same keyboard as the most classic 1391401, but a
>bit of an improvement.
>Anyone have any insight, aside from calling me absolutely insane?
I just got a nice reply from clickykeyboards.com about this:
In general, to the common person the 1391401 keyboards made by IBM are
relatively similar to 42H1292 keyboards made by Lexmark. Both
keyboards are excellent examples of buckling-spring keyboards and are
better than most modern keyboards.
The average person could not tell the typing difference by feel
between a 1391401 vs a 42H1292. Most people have to look at the back
label in order to determine if they have an earlier IBM-made 1391401
keyboard from 1986 - 1992 vs. a Lexmark-made keyboard from 1992 -
However.. there does appear to be some finer quality differences in
construction with keyboards made by IBM from 1986 - 1992.. in contrast
with later keyboards made by Lexmark.
We had an interesting email interchange with an IBM engineer from the
original IBM ps/2 design team. He was very interested in our site and
was thankful that there were people who appreciated his design and
engineering work. In general he said that IBM had very strict quality
control of their original parts suppliers and manufacturing process
when IBM made these keyboards. Originally these keyboards were priced
as $200 - $250 when IBM ps/2's were new in the late 1980s. However..
when the keyboard division was sold to Lexmark.. some shortcuts and
efficiency measures were taken to reduce overall cost. Finally.. the
keyboard division was sold to a company called Unicomp
In general, some of the additional differences between a 1391401 vs. a
- heavier overall weight (1391401 weighs 0.5 - 0.7 pounds more than a
42H1292). We think the differences are due to slightly thinner steel
plates and plastics used in later keyboards.
- use of electronic components vs. printed circuit boards (1391401
keyboards have more electronic components such as resistors,
capicitors and transistors.. in contrast 42H1292 keyboards combine
these features into fewer integrated circuit chips)
- difference in the quality of buckling springs used (some say that
1391401 keyboards are "clicker" and "springyer" than 42H1292
keyboards). I don't have a force gauge or metal analysis tools to
measure the differences, but the IBM engineer seemed to agree with
- there are also some differences in the imprinting process used to
put lettering on individual keys. Some of the later Lexmark keyboards
use only one color of black ink to print on the numeric keypad keys..
while IBM keyboards had key caps that were imprinted multiple times
with two color process (black color for the numeric number 1 and a
shade of gray for the second label of "End" on the same key)
In general... most vintage computer enthusiasts are purists/elitists
prefer the 1391401 keyboards with the earlier dates (1986 - 1992) and
slightly better construction.. in contrast to the more common and
mass-produced Lexmark and Unicomp keyboards from later dates (1993 -