So, how does one go about "looking after" LCD displays? Is it enough just looking at them, so they don't go black from feeling lonely?Thought it was about time to show off "the twins"...
It is however remarkably difficult to find these in working order as these old LCD displays, if they haven't been well looked after over the years, tend to suffer from pixel-leak which starts off as a few black dots on the edges of the display that then spreads until the entire screen goes dark!
Yessir. When I'm looking at Maxxum bodies that's one of the first things I check out. I have one with a few small dots on the edge that's in otherwise good condition, but the others are all pristine. If the ad doesn't show a clear view of the LCD I don't bother looking further.
The key to preventing image or pixel persistence is to frequently run a program (for calculators or computers) or use any self-test function that exercises the pixels, and couple this with frequently turning on and off the device and thus the display. General use of the calculator/computer/camera will usually ensure this type of exercise of the display and keep these issues at bay!
Yeah... It is important to have priorities!Theory schmeory.
I got rid of a couple boring TI59's today.
With boring modules and a bunch of magnetic strips. Also boring.
Had to make room for my new C/Y mount Yashica ML macro f:4/55 mm.
Priorities. Now, if I can only find my C/Y to M4/3 adapter. Last seen at the rear end of a Yashica ML f:2.8/35 mm...
Brings back so many memories!!!
I still have the Sharp PC-1211. However, as you pointed out, the display became completely blackThought it was about time to show off "the twins"...
The original pocket computers, the Sharp PC-1211 and its American brother, the Radio Shack TRS-80 PC-1, that both were released in 1980! In all fairness the TRS-80 is just a rebadge of the Sharp but it is quite nicely done!
And, as I can see, I've got 27 years worth of software license fees coming if you want to continue using my program!I recently got some calculators and pocket computers from @Erich_H and during my restoration of them to working order I found something really interesting!
One of the devices was a Casio FX-750P Personal Computer from 1985 with a RC-4 4K Ramcard with battery backup!
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Initially I checked it out and it was in good shape with some screws missing but nothing major! I put some new CR2032 batteries in the device but it didn't power on! This was due to the fact that the Ramcard slot lock switch was not working properly! If this switch is not detected in its proper position the device will not power on!
So I cleaned the contacts on the switch and tried again and it powered on but displayed only "???"! Some more research indicated that when the device is powered on with no working Ramcard in slot 0 it does not do anything! So I put the Ramcard in slot 0 and tried again but still nothing!!! As I read up on this system I found that the battery backup in the Ramcards were rated to last around 5 years so probably not a great possibility that anything was still going to be on the Ramcard! At least there is a capacitor in the Ramcard that allows you a grace time of about a minute to switch out the battery without it losing the contents! It is worth a shot and if nothing else I might at least get the device working again! So I swapped out the old battery in the Ramcard for a fresh CR2016 which I didn't really want to do initially as I wanted to find out if there was anything still saved to the Ramcard!
Tried turning it on again and the display changed to "P0" and as I kept digging I found that this meant that the Ramcard was detected but not available! I took the Ramcard out and opened up both the device and the ramcard and went over all the contacts and cleaned them with Isopropyl Alcohol, buttoned everything up again and tried turning it on! Success!
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Now it at least detected the Ramcard correctly and started up! Great news!
I still wasn't feeling to hopeful about the prospect of anything surviving on the Ramcard but decided to try anyway...
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Wait, what!?!?!? There is still something on the Ramcard!!!
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Turns out that this program was a simple program to print receipts on a thermal printer that you could get for this device together with a cassette interface!
Now I hope that @Erich_H can find that too if he still has it!
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In the REM statement the program has the date 1993-07-16 which means that it is roughly 27 and a half years sice it was entered!!!
Wow... they really underestimated the rated battery life on the tiny CR2016 in the Ramcard!
These kinds of adventures in Software Archeology is half the fun of reviving old computers and calculators!