28s Display Question



#18

I used a 28s for about 10 years until I lost it a couple years ago (can't remember the serial number). I recently bought a replacement on ebay (serial 2840A....) and have noticed that the display looks like it has much more glare than what I remember from my old calculator. Does anyone know if they changed the type of glass used on the display of the 28s?

I've been using my 32sii for a while so maybe I've just gotten used to the lower glare from that display and just never noticed the glare when using my old 28s.

Thanks.


#19

Yes, they did change the display at some time.

I have two HP 28s. One is from 1988. Its display can be used as a mirror. The other is from 1992 and has a much better display, no glare at all.

Unfortunately, at the newer calculator broke the battery door, I'm not sure if there is any coincidence ;-)

Maybe someone can narrow the time intervall more.

Bye,

Thomas


#20

Not sure about when Champion-series (e.g., 28S) calc's received low-glare display windows, but I have an two 42S models: an old-style 42S from 1989 and a newer-style from 1990. The older one has a flat, reflective display window, while the newer one has a recessed non-reflective "matte" window that seals out dust better.

The timeframe of that improvement would be consistent with what Thomas found.

I'm surprised that HP was still making the 28S in 1992, given that the 48S/SX had been available since 1990.


#21

Just a thought. We know what the earliest ones are. I've been watching the serial numbers on Voyagers to find the newest 11 and 15C's.

What do 'ya think Dave? A new museum topic?


#22

That would be interesting; the newest of each (discontinued) model.

Maybe the oldest and newest of variations such as ROM versions, the 32SII "brown bezel" and "silver bezel", and so on.

Regards,
James

#23

Quote:
I'm surprised that HP was still making the 28S in 1992, given that the 48S/SX had been available since 1990.
I suppose that as long as they were still selling and making a reasonable profit on a reasonable number of the "old" model, it made sense.

Regards,
James


#24

Quote:
I suppose that as long as they were still selling and making a reasonable profit on a reasonable number of the "old" model, it made sense.

The profit couldn't have been very high in 1992. I have looked again: My HP28s has the serial number 3208S00756, thus it was probably produced in February. I bought it new in March at a special price of 199DM, approx 100$. You could buy the HP48 at this time already, but it was far too expensive for a student.

Bye,

Thomas

#25

Karl (or anyone else),
Did all the Singapore made Pioneers go with the non-glare screen and the US made ones use the mirrored screens?

Curious to hear what other 32s or 42s owners can report. What's the earliest date that the non-glare screens began to be used?


#26

Thomas --

I have two Singapore-made 42S (readers -- neither is for sale): a flat-display from 1989 with S/N 2939S33496 and a recessed-display from 1990 with S/N 3047S06328.

Besides having the recessed, low-glare display window, the newer unit differs in at least two other aspects:

  1. The dot-matrix display area is taller with each pixel more rectangular, but unchanged pixel dimensions (to my knowledge). Numbers are taller, but not wider. I'm not so sure that the aspect-ratio change was an improvement.

  2. The firmware was revised. Two effects included the introduction of the minor COMB/PERM bug; and, not allowing the clock speed to be temporarily altered by executing a program (e.g., the "FAST" program). Both of these were discussed in the MoHPC Forum archives more than a year ago.

#27

"(e.g., the "FAST" program). "



Where can I find it?

[VPN]


#28

Veli-Pekka --

I found the Forum references to these two items pertainig to the HP-42S:

Double-speed "fast" mode:

HP-42S "FAST" program

Also, item #26022 in the Archives, posted 11 Jan 2003 at 9:38 AM by Gene Wright.


HP-42S COMB/PERM bug:

Item #17122 in the Forum archives, posted 5 May 2002 at 6:45 PM by Ken Garges.

#29

I know of an HP41 on a machine tool that was mounted at just the right angle to be unreadable becuase of reflected overhead light. A little find steel wool did wonders...

#30

My serial 2922Axxxxx 28S has the same display glare as my 28C.

Regards,
James


Edited: 14 Mar 2004, 3:19 a.m.

#31

I think that the difference lies in the place/country of production. All 28S that i came across had either the glare glass, and these where all made in the USA, or the non-glare ones, and these where all made in Singapore.


#32

Affirmative! 2829A07612, made in USA, bought right after market introduction, has glare display.

Andreas

#33

Erwin stated,

Quote:

I think that the difference lies in the place/country of production. All 28S that i came across had either the glare glass, and these where all made in the USA, or the non-glare ones, and these where all made in Singapore.

Perhaps the design change coincided with a shift to production in Singapore. It was not uncommon for HP to start production of a new model in the US, then shift it after some time to Singapore or other location later. The 41C and all Voyager models (10C/11C/12C/15C/16C) all began production in the US. As far as I can tell, the 41C shifted to Singapore after at least a year; the 12C moved to Singapore after the other Voyagers had been discontinued.
First-year Pioneers from 1988 (e.g., 42S) were US-made; however, my 1989 "glarey"-style 42S is Singapore-made.

I suspect that the 28C had alredy been discontinued when the design/production change took effect.

-- Karl

#34

For those who have the high glare 28s versions, has anyone tried cutting to size a Palm Pilot Screen Protector and using that to reduce the glare? I may give that a try this week to see how it works. This idea may also help protect the 33s screen that seems prone to easy scratching.


#35

Well, I have two 28Ss, one from the US (2921A) and one from Singapore (3048S) and the US model has a high-glare screen while the Singapore unit doesn't.

I like that idea of the Palm protective screen...I think I may give it a try, because I find the high-glare screen REALLY annoying...

B.


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