Commodore & Sharp calculators


I came around to these calculators :

Commodore SR4148

Could anybody give me some details about it ? Does anyone know to what voltage I should plug in an adapter ?

This one is more for Valentin.

I remember a schoolmate had one of these, actually this calc is a programmable calc where you could store formulae pretty much in Hp style.

All comments welcome !


I have the SR4190 (Dismac HF-37PR, brazilian clone) and SR9190. The SR4148 isn't much different, I guess. Mine SR4190 uses a DC 6V non-regulated input (positive center), and their NiCD batteries are internal (non-removable). I think that they won't work without the batteries.




Wow, brings back memories. I used to have the Sharp EL-512 way way back in the day. It was a great calculator and served me well. I went from that to my 48-SX and never went back to algebraic calc's. Wish I kept this model. Nice pic's.



The pictures are just a scan of the calcs themselves... This is the easy way to do so. Main disadvantage is that it makes look the item far worse than it is actually...


my take,

be careful with commodore units that have internal cells. they normally have 3AA nicads. these leak and burn the circuit board. you should remove the old ones asap.

you have two choices
(1) rebuld the internal batteries. to do this you will need to obtain tagged cells and even then they might not fit. the cavity inside the case is tight. i have tried to build a *very* slim holder for batteries so i can put in regular cells or regular chargable cells without them being soldered in. this plan has failed. my thinnest holder is too fat.

(2) remove the cells and run the unit from external power. do *not* power it from the correct mains adapter!! the correct adapter will put out something like 9v and damage the unit (the internal cells act as a load). i have found the unit powers happily if given the equivalent 4.5v from external power.

good luck,


I rebuilted my SR4190 battery pack with one from wireless telephones batteries such as Panasonic KX-A36A (NiCD, 3 cells, 300mA/H) or another with more mA/H (NiMH ones). They fit perfectly inside and are sealed.




Thibaut posted:
"This one is more for Valentin."

Congratulations on your lucky acquisitions/findings ! Regrettably I'm no expert in this marvelous Sharp EL-512 model, as my respectable Sharp collection includes only BASIC-programmable models except for a couple Sharp EL-5101 algebraic-expression calculators (most beautiful machines indeed) and one quite peculiar Sharp EL-8029 pen-like vintage calculator (very nice readable display).

Glad to see there's another serious & dedicated HP lover who does also appreciate outstanding models from other manufacturers. Keep on going ! :-)

Best regards from V.

Edited: 28 Sept 2003, 7:01 p.m.


I liked the longer slide-rule like style. Got one of these when they first came out. It had a nice hard case that would hold the calculator. Also had interface for printer.

Edited: 28 Sept 2003, 7:15 p.m.


Congratulations for your fine-looking Sharp PC-1211 !

This was (and still is) an extremely fine, revolutionary machine, contemporary of the original 41C no less. It was less than half the price, yet it included such revolutionary characteristics as a 24-character alphanumeric dot-matrix display (the 41C was doing its best with a meager 12-char, segmented display), I/O to inexpensive magnetic tape and printer, 1680+ bytes of memory (equivalent to a 41C plus 3 RAM modules), redefinable keys, and high-level BASIC programming (instead of low-level, assembler-like RPN).

You could key-in expressions just as written, with such byte-saving niceties as implied multiplication (i.e: 5AB instead of 5*A*B), parenthesis supression (i.e: SIN X instead of SIN(X)), automatic parenthesis-balancing at the end of an expression (i.e: 5+SIN(2+3*(5-X with no need to include the two closing parenthesis), abbreviated entry (i.e: I. instead of INPUT), keyword tokenization (i.e: INPUT took a single byte to store, not five), multiple expressions per line (i.e: X=2+3, Y=3-7, Z=2*SIN(X+Y)), and further you could recall the *whole* expression to the display after evaluation, for further editing and reevaluation (instead of LASTx in the 41C). Also, in case of errors, the expression would be recalled automatically with the flashing cursor pinpointing the exact location of the error.

All in all, a wonderful, revolutionary machine. You could do wonders with it, I wrote 100+ programs for it at the time, and most would do in just a few simple lines what you'd need hundreds of steps to accomplish on a 41C, say.

This was the machine that made me reevaluate my fixation for HP products and start my collection of Sharp machines. A true revelation. BTW, I've got 3 of them, plus two TRS-80 PC-1 models which are exactly the same machine, only this time manufactured for Tandy Radio Shack.

Best regards from V.



You have accurately described some of the nice features of the PC 1211, also marketed by Radio Shack (IIRC as TRS80 Pocket Computer).

I followed those models at the time, but political and economical circumstances in my conutry made us "disconnect" from such advances after 1982. I needed about 10 years after buying my HP 41C to be able to buy my next calc (HP 42S). The 75C and 71B were skipped, as the Voyagers did.

(OK, I also get married and become a happy father during these years, so HP calculators had to wait for a while...)

To the point: How would you compare the PC 1211 against the HP 75C/D and the HP 71B?

I assume these HP models were more expensive than the Sharp unit, but perhaps are more comparable to it than the HP 41.

Edited: 28 Sept 2003, 8:43 p.m.


Andres wrote:
"To the point: How would you compare the PC 1211 against the HP 75C/D and the HP 71B?. I assume these HP models were more expensive than the Sharp unit, but perhaps are more comparable to it than the HP 41."

Well, yes and no. "Yes" because all are BASIC "pocket computers", and "No" because it would be an outrageously unfair comparison.

Why ? Because the Sharp PC-1211 model is a pioneer-like machine, the very first handheld to feature BASIC as its programming language, released circa 1980, and designed to compete against 41C-class machines, thus its characteristics and, most importantly, price, are targeted to that segment.

On the other hand, the 75C and 71B (released circa 1982-1984) are *much* more expensive machines, 25 times and 10 times costlier, respectively, and are targeted to the business and engineering markets, not the casual home user. They are more like instruments or advanced tools than mere calculators/pocket computers. The 75C was squarely aimed to business users at first, what with its large alpha keyboard, appointment applications and Visicalc. The 71B was similarly aimed at engineering professionals, intended to be the controller of a number of advanced, specialized digital-capable instruments, via HP-IL and a number of interfaces.

This being so, comparing any of them to the Sharp PC-1211 is an utterly preposterous mismatch, and should not be done, IMHO. It would be like comparing the 41C-class machines to, say, the HP-25.

Anyway, they share a number of important characteristics in common, namely:

- large, dot-matrix alphanumeric display

- I/O capabilities, including printing and mass storage

- BASIC language

- ability to evaluate algebraic expressions directly, while being able to recover the whole expression after evaluation

- instant-mode calculations without programming

- redefinable keyboard

but the differences in speed and features are overwhelming. Nevertheless, the Sharp PC-1211 is a pleasure to use, and has a larger display than the 71B, and for casual programming and use as a powerful, programmable pocket calculator/computer, it does more than deliver.

Further, though its BASIC interpreter is way simpler than 71B's, it *does* include some capabilities that the latter doesn't such as computed GOTO/GOSUB (i.e: GOSUB 200*X+100*((Y>5)+(Y<8))+200*Z or GOTO B$), and you can save hundreds of programs on inexpensive cassette tape instead of quite expensive mag cards or digital tape drive.

Best regards from V.

Edited: 29 Sept 2003, 5:47 a.m. after one or more responses were posted


The HP-75 is a direct CMOS copy of the HP-85 PC (8-bit CPU), which was "current" at that time. The cost was very justifiable for the users of the bigger brother. The Visicalc module was the key sales factor and other expansions, including then popular HP-IL, gave versatility. Using a Video adapter you would not even need that heavy HP-85, at least not if you were traveling around.

The HP-71 was the only BASIC computer to follow the IEEE standards in math. There is no comparison for it's math features! Expansion for HP-IL (cassette or disc drive, etc), RAM, MATH, Curve Fit, Finance, FORTH/Assenbler (including a HP 41C emulator) gave it versatility.

What can I say? They were expansive, but worth it. I had them *AND* I re-bought them lately!!!

I also still have two Sharp calculators: PC-1500 (with expansion cradle and a plotter) and PC-1261. The Casio FX-702P that I also own, is much harder to use than any Sharp or HP due to limitations in editing and BASIC language.


VPN wrote:
"What can I say? They were expansive, but worth it."

Only if you could afford them, which was extremely unlikely if you were a student at the time, as I was. The HP-75 was some US$ 2,500 (1982's dollars), and the HP-71B was US$ 750 (1984's dollars) and there was no way I could get that much money then, let alone forking it our for a 'calculator'.
The Sharp PC-1211, on the other hand, was just a mere US$ 120 (1981's dollars), which was a reasonable price I could actually afford and I did get one.

"I also still have two Sharp calculators: PC-1500 (with expansion cradle and a plotter) and PC-1261."

You'd do well to try and get a Sharp PC-1350 (or 1360). You'll find it's much more lighter, smaller and stylish than the 'brick-like' PC-1500, and after getting used to its wonderful 4-line, 96-character graphics display I'll bet that you'll find the HP-71B's 1-line, 22-character display next to unusable for program editing and results output, as it actually happened to me, after many years using and programming the HP-71B.

Now the Sharp PC-1350 (together with the HP-15C) is my usual, everyday pocket computer for quick programming and manual computations while the HP-71B (all 3 of them) are comfortably stored in their drawer. After being spoiled by the four lines available to key in the longest of expressions in full view, without reordering anything, without ever getting lost, I just can't stand the ultra-cramped, always-scrolling HP-71B's display anymore.

Best regards from V.


im with valentin on this one. the pc-1350/1360 is top kit. i used one for years and found it highly versatile. you can set up key abbreviations to your liking, the 4 line display is lux and programing is a doddle.

very well made units too.


Just note that the PC1211 has 1424 steps (bytes) available to the user.
If you want one of those excellent 4-line Sharp machines, you'd rather turn to the PC1600 for absolute top of the line. Alas, it's hard to find, and has the 'brick' style of the 1500.
Another possibility is the PCE-500 which has all what the 1350/1360 has, and more. Expandable to 512K, and still available brand new in Germany, as the updated 'S' version.

HP should have made multiple-lines Basic machines, but maybe it would have been too 'fun' ? Also, prices were maybe justified, but out of reach. This probably leaded them to -erroneously I believe- give these the axe. Too bad.


Well, trying to be positive with HP, a 95/100/200 LX with MS-DOS 5.0 and QuickBasic is a nice "HP palmtop with BASIC and multiline display"...

And it also has a very nice calculator application with 4-level stack RPN and Algebraic modes, a good scientific and financial functions repertoire, graphing, etc... running in a 8086-class machine. (Emulator fans, please note!!!)


GE posted:

"Just note that the PC1211 has 1424 steps (bytes) available to the user."

Nope. It has 1424 bytes available for programs *plus* 26 fixed variables A-Z, plus 48 bytes for key definitions, which makes a total of 1424 + 26*8 + 48 = 1680 bytes available to the user. I'm not counting internally reserved memory, such as 80 bytes for the command-line input buffer, the stack for operators and operands, etc.

" If you want one of those excellent 4-line Sharp machines, you'd rather turn to the PC1600 for absolute top of the line. Alas, it's hard to find, and has the 'brick' style of the 1500."

Exactly, it's "brick-like", i.e: large, heavy, and bulky, and eats batteries pretty fast. I still stand for my recommendation to get instead a Sharp PC-1350/1360, which is far lighter and smaller, its batteries last many months, and has a lot of memory, 4x24 char graphic display, and tons of advanced functionality. The PC-1600 is *not* a good choice at all for an everyday-use machine, and it's also quite rare and thus very expensive, while a 1350 can be had for as few as US$ 25-50.

" Another possibility is the PCE-500 which has all what the 1350/1360 has, and more. Expandable to 512K, and still available brand new in Germany, as the updated 'S' version."

The PCE-500 is far larger than the HP-1350/1360, much less 'attractive-looking' (i.e: uglier), and has a plastic body instead of metallic. Its screen is also much darker and much less easier on the eyes than the luminous, clear screen of the 1350. But the biggest problem is it's very bulky, it certainly fits no pocket whatsoever, and takes a fairly
amount of space in your briefcase. Not in the same league as the slim 1350. It also eats batteries very fast.

As someone else posted recently, remember this proverb: "The best is the enemy of the good". Don't strive to get 'maximum functionality' at the expense of convenience, else you may find yourself with an HP-49 in your hands.

Best regards from V.


You say:
"The HP-75 was some US$ 2,500 "

Where did you get that number. I bought one when they first came out and didn't pay half that.


I agree that $2,500 is way too much. I bought my HP-75C in 1982 at the BYU bookstore for $995 less 10% discount (end-of-semester sale) and another 10% off for my parents' staff discount.

It came to less than $850 with tax. It was the first thing I did with that year's student loan.

Mark Hardman

Edited: 29 Sept 2003, 11:20 p.m.


Mike wrote:
"You say: "The HP-75 was some US$ 2,500. Where did you get that number."

From my HP sales representative in Madrid (Spain, Europe) circa 1982. They were sold at those outrageous prices abroad. If I recall correctly, Wlodek says in his "Guide ..." that the HP-71B was sold at something like 700-800 sterling pounds in UK, which is also a truly awful lot of money for something that at the time essentially seemed like a calculator.

As far as I know, HP Spain sold extremely few HP-75 units in Spain ... if any ...

Best regards from V.



You're right. I actually bought one (Spain, 1983) and yes, paid such an outrageous sum of money for it. (Remember SIMO'83?)

Interestingly enough I sold it 6 months later for about the same price... who knows, maybe it was the only one HP sold in Spain that was circulating amongst users :-)




It's odd that they would charge more than double for the 75C but about the same for the 71B. Strange marketing.


HP was once well known for its crappy marketing.Examples abound, one of them being HP-NewWave (but that's another story).

In fact, this is the company that had they been in the sushi market, they would have advertize it as "deal, cold fish"...




Thank you very much, this is just the kind of opinion that I was wxpecting to clarify the issue for me.


Hello Andrès,

As pointed by Valentin, the PC 1211 is the first of his kind and could not be compared with HP 75. I suppose that the more advanced PC 1500 or PC 1600 are better candidate. But as I don't have an HP 75 or 71 I can't do the review myself.
The PC 1211 could not even be compared to the HP 41, as they are very different machines with different philosophy.
To make things short the HP 41 has more built-in function and more interface possibilities, but the Sharp is far easier and faster to program when dealing with large formulas. The connecting possibilities of the Sharps pocket computers to nearly every kind of tape recorder is a great advantage also.
Then specially to Valentin :
I sometime post in two new forum dedicated mainly to Sharp machines :
There is still few contributions and we lack good pens.
So we wait for you Valentin !

All the best

Pierre Brial


Although I'm not a big TI fan, I do like this particular model.

Wish I had a manual for this.

Edited: 1 Oct 2003, 11:43 a.m.


Best regards from V.


Wow, that picture of the SR4148R brought some memories flooding back.

It must have been about 1975 when I got mine. I was ten years old. At school we were free to choose whatever calculator we liked as long it had certain functions that we needed for the maths lessons. There was surprisingly little duplication.

The machine you chose said a lot about you. I was very proud of my Commodore and thought it easily the best calculator in the class! Today, I still remember some boys just because of the calculator they had. There were one or two with HPs. One with a TI. Mostly Casios though. There was one other boy out of about 25 with another 4148.

Something that makes me smile every time I think about it was the lessons we had where we did our calculations from log books even though we all had calculators. This was because, as our teacher explained, we'd always be able to find a log book but we couldn't always guarantee that there'd be one of these new-fangled calculators to hand.


Your story made me laugh. A young lady once came into a lab class without a calculator (this is less than ten years ago). She wanted to be excused without penalties on this basis. A technician silently and promptly disappeared into his lab and reappeared with log tables. The young woman stared in a confused way at them and exclaimed, "I need a calculator and you bring me sheets of paper?!"

The tech and I, well, we bemoaned the reality (nowadays) that you can almost always get a calculator but almost no one even knows what those charts of antiquity even mean.

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