Sharp ZQ-5000

Much more than a calculator, this was an early PDA.  In fact, the term "PDA" didn't yet exist and it was called a "electronic organizer".  Before this, you carried everything around in a little looseleaf notebook that didn't stay little for long.  This fit neatly in the inside breast pocket of a suit jacket.  Solidly built with just the right heft, it closed with a positive lock and was well protected in its hard but slightly rubbery shell.

I used this in the early '90s and it was great.  The display folds back both flat and slightly tilted, and the keyboard is big enough to touch-type on if you're careful.  It not only kept records, but exported reports to your PC for printing or import into a spreadsheet.  It even sported an "Options Port" to which you could connect a mini thermal printer.  I think the monochrome LCD display was about 8 lines of 20 characters.


Sharp EL-506H

Nice wallet-sized calculator in a brushed aluminum casing (but note how easily it scratched, despite the plastic cover.)  This has a really strong feature set including hex, angles, coordinates, and simple statistics.  

Got this around 1980 for opening a checking account in Kalamazoo, MI.

Sharp EL-8048

Intended as a way to transition Eastern abacus users to electronic calculators, it's hard to imagine a less useful device!  But it does have that handy pencil tray!

The LCD display shows some leakage, but it's fully functional.


Sharp EL-5500III

This is a very well-endowed 6K BASIC computer with a calculator attached. 


In CAL mode, you can use the full featured scientific calculator in the usual way.  Then in BASIC mode you can either enter a program in the PRO submode or execute instructions immediately at a "command line" in the RUN submode (aka "manual" calculation.)

That is, in RUN you can type 

1+ 2 <enter>

and the display will show 3.  Or enter:

A = 1 <enter>
B = 2 <enter>
A + B <enter>

and the display will show again show 3.

It is interesting that to calculate something like log(2), you would, in CAL mode, press the "2" button and then the "log" button.  But in RUN mode you would press the "log" button to enter "LOG" into the command line, then press the "2" button to type "2" into the command line, and finally press "<enter>" to execute the whole command.

Very little is shared between the calculator and the computer.  E.g. a value stored to memory in CAL mode is not available in BASIC mode, and variables set in BASIC mode can't be recalled in CAL mode.

The one exception is statistics.  If you enter data in CAL mode, several statistical results (e.g. the sum of the squares of the data items) will be available as "fixed" variables in BASIC mode.

You can also perform limited CAL-style calculations on a result calculated in RUN mode.  E.g. in RUN mode you can type:

1+1 <enter>

and the display will show 2.    

If you then press the LOG button, the display will show .3010 - i.e. a monadic mathematical function button will immediately act on a numeric result returned from a command instead of causing the function name to be typed onto the command line.  

If you don't want this to happen, you can type

1+1 <enter>

and then press LOG (or any monadic function).  The function name "LOG" will then be typed into the command line.  If you next want to append the last command's result, you can press the <up-arrow> button.  In this example, pressing LOG <up-arrow> would cause the display to show

LOG 2.

and then pressing <enter> would evaluate it and return 0.3010.  

The computer has an interesting and dangerous quirk.  When a program reaches a PRINT instruction, the default behavior is to display something and then wait for the user to press ENTER to continue the program.  (A prior WAIT instruction can cause the computer to wait a given amount of time and then continue w/o making the user press ENTER.)

But the computer is actually at the "command line" while waiting for the user to press ENTER.  The user can type anything and get results.  As long as he does, the next step of the program is still pending.  Only when he presses ENTER without having typed anything first will the program continue.

For example, suppose a program is this:

10 A=1
20 PRINT "A=";A
30 PRINT "A=";A

When the computer hits line 20, it will display "A=1" and wait for the user to press ENTER.  But instead the user can type

A=2 <enter>

at which point the display will just show 2 (the "result" of assigning 2 to A).  If the user now presses ENTER the program will continue to line 30 and display "A=2"!  

Indeed, after a PRINT statement, the user can modify variables and do interim calculations of any sort before resuming the program.  He can even RUN/GOTO a different program altogether!  Yeesh.

Sharp CE-129P

The EL-5500III, above, could be docked to this device, to provide printing ability and a connection to a separate cassette tape player in order to save/restore programs and data.  It runs on both batteries and AC via a power adapter (not included with the printer.)

The printer comes in a vinyl folio, providing protection and portability.  Unsnapping and opening it to reveal your portable computer must have made an impression back in the day!


Servamatic Solar

I'm putting this under Sharp because it uses a Sharp LI3128MS chip.  But it could have been built by a 3rd party, perhaps specifically for Servamatic Solar Systems, Inc., a HVAC company in California.

I have to call it cute, and yet wholly impractical.  In fact it's a pain to actually use!  

Note the negative sign at the right end of the display!

I've been able to date the application for a trademark on the stylized sun image to 1983, and I'm guessing the calculator was made around then.


Sharp Elsimate EL-203

Quite nice, really.  Note the trailing negative sign.

This belonged to Aldyth Parle of some office within Santa Clara County.  If that's you, drop me a note! 


Sharp Elsimate 8144E

This is really cute.  

It adds calendar, alarm clock,  and stopwatch functions to a 4-banger.  

And it's tiny and thin!  Only about 1/8 in thick just slightly larger than a business card. And no keys - just a touch sensitive membrane.  Due to the lack of tactile feedback, you can make the keys chime as you press them.

This was something to tuck unobtrusively into your suit-jacket's inside pocket and leave your wristwatch at home.

Sharp Elsimate CT-500

This is a jewel piece.  

Enclosed within a brushed, goldtone, aluminum clamshell, is an international calendar-alarm-clock, stopwatch, and calculator.  (Again, with trailing negative sign.)

It must have been too pretty to ever use, so this one is in flawless condition.


Sharp Elsimate EL-5808

A real beauty!  

About 1/8" thin in a solid black anodized aluminum slab is a scientific calculator with a membrane keyboard.  It has a very solid heft to it and, thin as it is, you don't feel there's any danger of cracking it in half.

As nice as this calculator was, I'm betting it didn't hold up well.  That membrane is just too thin and I bet it wore quickly and tore easily.

With some regret, I sold this near perfect one in early 2013 for $235 to finance over 30 other acquisitions.


Sharp EL-230

Just a simple 4-banger with memory.  Works great.  Once again, a trailing negative sign.

Sharp EL-220

Take one key away from a 230 and you have another simple Sharp.