RES Mark I: One of One, for Now

The sole printed reference book for calculator collectors, "The Complete Collector's Guide to Pocket Calculators" (Ball & Flamm, 1997) states on page 16 that, as of that time,

"Previously unknown models continue to surface, adding to the excitement."

That appears to be true roughly two decades later, as the RES Mark I seen here is the only known example; it appears nowhere on the net*, is not in the Ball & Flamm book, and has no references anywhere that we can find.  For the moment, this calculator is the only known example.

RES stands for Radiant Energy Systems, a California company known to have been working on developing methods to improve the manufacture of printed integrated circuits in the early 1970's but about which not much else is known.  California business records show that this company existed only for the ten year period 1969-1979, making it yet another one of that phalanx of companies which got in with the rush of IC's, calculators and the like and which also did not survive the decade.  The calculator in question was won on auction this year, and came complete with box and sleeve, shipping (cardboard) cover and instruction book.  It is of interest to note that the label "Made in Hong Kong" is a sticker, applied only to the one side of the box - the other being identically printed but omitting the sticker.

The calculator, which is serial number 010141, is an eight digit machine having memory, as well as memory exchange, sign change and percent functions.  The calculator has strange, small, clicky keys which have raised edges and stickers in their centers.  The calculator operates on a 9V battery or an AC adapter, which is not included and whose model is not referenced.

Like many early calculators this model does not clear on startup and also has the negative zero bug.

Startup gobbledygook on RES Mark I screen before clearing.

The display of the RES Mark I will shut down to just a "-" in the center of the display after 15 seconds of no use; the EX key is depressed twice to restore the display.  (This simply exchanges the previous keyboard entry; use of the C key will restore the display as well but clears the operations.)  The clear key on this machine acts as 'clear entry' on the first depression and 'clear all' on the second. As mentioned, EX swaps the last entered figure with that previous for inspection of possible error.  

An automatic constant feature is included on the machine, it being the last entered value in a calculation.  For example to use the number 37 in a set of calculations as a constant, the operator might first enter "100" and then hit "+" and then "37" and then "=".  The number 37 is automatically the constant; if the operator then presses "10" and then "=" the calculator will toss the previous final result, add the new entry 10 to the constant 37 and display 47.

Some collector references such as Ball & Flamm and some websites do feature some other known Radiant Energy Systems calculators, but none is this model and none matches it.  We're quite lucky for now to have an "only one known" calculator, although prior collecting experience tells us that sometime soon another will come up.  What's interesting now is that even this long after the end of the classic era of early calculators (1971-1979) there are still unknowns like this that can pop up!

* - The RES Mark I pictured on Serge Devidts' "Calcuseum" website is this example; apparently the photos were taken from the auction page.  RES Mark I serial 010141 is in the Will Davis collection.

An Early Novus

Collectors will often run across calculators manufactured by National Semiconductor, especially those carrying the name "Novus."  This name was adopted by the company for calculators in the mid-1970's to sell along with its NS Electronics and National Semiconductor brands; the conventional thinking (see Ball & Flamm) is that the different brand names allowed the company to market similar calculators at slightly different price points.

I've turned up an oddball Novus, seen here, that is pretty unusual in that it has no model number whatsoever, front or back.  The calculator simply is named NOVUS.

The calculator is a basic four function machine with an = key, which is not what's usually found on the cheaper end of the Novus line.  This machine also has a K (constant) feature and auto-display shutoff at 25 seconds of inactivity; the D key is used to restore the display.  The serial is 022588.

Unfortunately the calculator came just as you see it here - that is, no box, instructions or receipt.  It does work however and displays two hallmarks of either early or else very cheap calculators.

Above we see the display of the Novus after switching on.  This calculator does not automatically clear itself on startup; the user must use the C key to clear it before attempting any calculations.  While a range of E's as seen here is common the display may be blank or filled with random digits on startup.  

The Novus also has the "negative zero bug."  This means that the calculator will display the value zero with a negative sign attached.  To test for this, use the calculator to subtract to a value below zero and then add back up to exactly zero.  If the calculator retains the negative sign, it has what has been called the "negative zero bug."  This was designed out of later / more expensive calculators which test for a result of zero and then remove the carried-along negative sign.

So when was this made?  Well, advertising is almost wholly absent, but we do have some hints.  Inside the calculator however, on the circuit board section supporting the LED display we find two part numbers as seen here which may be of some help:

The stylized NS emblem (associated with the NS Electronics brand) seen on this card first was used by the company, according to the US Patent and Trademark Office, on September 5, 1973.  (I am assuming that the two part numbers are for using this particular part in either Novus or NS Electronics branded calculators.)  Novus brand calculators began using a stylish emblem which resembles a 'swoopy' letter N in June, 1975.  These two dates almost certainly bracket Novus serial 022588 here, and adding in hints from sparse advertising data it might be safe to guess that this calculator appeared in 1974.  It also might well be the first model carrying the name Novus, although this is not an entirely safe guess.  The calculator's gold face plate is not unlike that seen on some early Novus 650 and/or Mathbox calculators, it should be noted - and it should also be noted that this calculator fairly closely matches the known Novus 820 model except that the 820 has a silver face plate and has only a C key, not a CE/C.  The Novus 822 "The Professional" appears to have developed from this Novus and the Novus 820.  

What is safe to say is that this Novus is unusual in having no model number - and for that we're glad to have it here!  If you can add any information, please do so in the comments.  

Melcor 370: "First 100% Solid-State Calculator"

Melcor Electronics Corp., located in Farmingdale, New York was a significant but early manufacturer of small or pocket-sized calculators which didn't survive the decade of the 1970's.  It did however contribute some interesting calculators for collectors to ponder today and, it appears, did in fact make some history by offering to the trade the first fully solid-state calculators - its models 360 and 370, which were among the first models offered by the company in 1972-1973.

Here, we will consider the 370 as seen below.  Note that this calculator is missing its make/model label below the display but is otherwise not only intact but operable and, fortunately for us, also has its original instruction book.

At once the Melcor 370 can be seen to have an unusual feature; the model incorporates a touch pad instead of more normal keys or buttons.  This feature, referred to by Melcor as the Touch-Tronic keyboard, is described in the manual as follows:

"Your calculator features the Melcor space age Touch-Tronic keyboard which provides the ultimate in reliability.  With a little practice in the technique outlined below, you'll enter numbers and operations faster and more accurately:

1)  Entry is made by pressure on the key pad.  There is no actual movement.
2)  Approach the key pad with your finger nearly parallel to the top surface of the calculator.
3)  Bring the ball of your finger down rapidly into the key opening and apply moderate pressure to the key pad.
4)  Withdraw finger rapidly from the key pad.
5)  Do not attempt to brush or "tease" key.  The keyboard is very sensitive and this may result in entering two numbers.
6)  Do not use fingernails or other sharp objects on keyboard.  This may damage calculator and will void warranty."

In addition to not having an inbuilt debounce feature (which later calculators incorporate to prevent double or triple digit entry upon light pressure to a key) this calculator also shows another feature common to some very early calculators:  The Melcor 370 does not have automatic clear upon startup.  When the calculator is turned ON, the display will likely have a nonsensical number displayed with one, two, three or more decimal points.  The calculator must be cleared before any calculations can be done by depressing the C key.  Later calculators have an inbuilt automatic clear function upon startup.  Below, we see the Melcor 370 immediately after having been turned on; the gibberish result in the display (which is not repeating, but totally random) is proof that the calculator doesn't have clear-on-startup.  This feature of early calculators has carried on to modern users who instinctively clear calculators on startup even today, even though they've been built with clear-on-startup since the middle 1970's.

Once the calculator is cleared, another feature that a number of early calculators had but which was considered confusing and was later engineered out is shown; the calculator always powers all digits of the display, even if they are zeroes.  Eight digits are always displayed, and the decimal point floats to wherever it's required in the display.  Here is the calculator after having been cleared and awaiting the performance of actual work.

(Note that the right-most digit does in fact have a failed LED segment, upper right.) 

Performance of calculations with this machine can incorporate digits beyond the eight displayed as is described below in a shot from the Melcor 370 instructions; most calculators of this day would overload if beyond the display limit.

When a calculation is performed, as noted earlier and above, the display will still be fully lit all the way across; "automatic zero blanking" was still in the future.  Below is the result of muliplying 9 by 9 to get 81.

One feature the Melcor 370 does have is prevention of false entry on double key depression; this prevents two keys being pressed simultaneously from making an input on the second key to be hit.

Speaking of keys, it's the on/off key that really allowed Melcor to claim that this was the first 100% solid state calculator, since the use of the on/off key removes having any kind of mechanical power switch on the machine.

(Above - Melcor 370 instruction book front cover.)

And speaking of power - the Melcor 370 is, properly, a two-model range comprised of the sub-models 370B and 370R.  The 370B, which we're showing here, operated off of a disposable 9V battery but also had an AC adapter port.  On a number of early calculators of various makes and models, the use of the AC adapter would attempt to charge the disposable batteries, so the operator either had to ensure no battery was installed in AC operation or else in some cases a switch was supplied to ensure the battery didn't explode.  However, on the advanced Melcor 370 the battery was automatically disconnected when the calculator was AC powered.  The other variant, the 370R, included a non-replaceable, rechargeable nickel-cadmium battery pack which had to be recharged through use of the adapter.  According to the instructions, the 370R model would charge the battery whether the calculator was on or off, but would only charge at about 1/4 the normal rate if the calculator was being used while the battery was charging.  Interestingly, according to the book the 9V battery version would run about 7 hours in use before needing a new battery while the rechargeable version would only run about 4 hours before needing a recharge. 

As we know today, calculators with keypads didn't last long - either in use, or in a larger sense, on the market.  While several makers tried this kind of design in the early-mid 1970's it must have proven to be more trouble than it was worth, and all of them (including Melcor) changed to calculators using conventional keys (or "buttons").  Below, we see the Melcor 370 with the very next model, the 380 (which uses a very different keyboard and a new case) as well as the later 392 (same case as the 380 but with yet again different keys.)  We'll see more Melcor calculators on the blog so stay tuned.

Melcor 370, 380 and 392.  It's interesting to note that the oldest, the 370 at left, has the Touch-Tronic keypad and a single on/off key; the 380 at center has the Melcor Full-Travel keyboard with separate on and off keys, while the 392 at the right has a conventional on/off mechanical contact type switch.

JCE Mark II

Even the most casual user of calculators of any era is likely to recognize common brand names such as Texas Instruments, Sharp, or Casio - but would be highly unlikely to recognize the brand of this calculator since the company responsible for it did not survive longer than perhaps a couple of years in the early 1970's.  Today, this is an unusual calculator.

At hand is the JCE Mark II, manufactured probably about 1972 by John Colling Enterprises.  This company, located in Palo Alto, California, seems to fit the pattern of dozens of small startups at that time which entered the calculator competition in that it purchased major components used in its calculators from other makers.  In fact, both the main chip and the keyboard in the Mark II are products of Texas Instruments.

As can be seen, this calculator has (as was common at the time) no dedicated "=" key.  Instead, the "=" sign appears on the "+" and the "-" keys.  Operation with a keyboard such as this is as follows:

Addition:  To add the numbers 15 and 20, the operator first clears the machine with the C key.  The key operations are then 1, 5 and +/=.  The display now shows 15.  Next, the operator presses 2, 0 and +/= with the final key stroke resulting in the machine adding the two stored numbers and displaying the result as 35.

Subtraction:  To subtract the operator must first enter the minuend or the number from which another is to be subtracted and depress +/= to enter that number into the calculator.  The operator then must enter the subtrahend, or the number to be subtracted from the minuend and then the operator will depress the -/= key to perform the actual operation and display the desired result.  For example, to perform 8-6=2 the operator presses 8 then +/=, followed by 6 and -/=.  The screen will then display the result, 2.

In multiplication the operation is more like that of what today's users would think is normal; the two factors (or, if you prefer, the multiplicand and the multiplier) are entered with only the "x" key between them.  However, to perform the multiplication operation the +/= key must be used.  As an example, to multiply 2x4=8, the operator would press 2, then "x", then 4, then +/=.  The display would show 8.

The JCE Mark II also has a K or Constant switch which is used to force the calculator into Constant mode.  After the K switch is moved to K position the next number entered will become the Constant.  Also, the calculator has a three position decimal control switch on the front edge of the case with positions "F 2 3" for floating decimal point, fixed 2-place decimal display and fixed 3-place decimal display.  The calculator displays eight digits; will display an E if any entry exceeds eight digits and a square if any calculational result yields more than eight digits to the left of the decimal point.

What's the D key, you say?  Many early calculators have a key such as this; on these machines the display shuts off automatically after a period of inactivity to save battery life.  Pressing the "D" key restores the display.  However, oddly, the Mark II instructions mention no auto display power off and in fact tell the operator that the operation of either the CE or D key simply clears the last entered number.  If we can get either of these in condition to operate, we'll test that out.

I actually have two JCE Mark II calculators.  On the left is a very early example, with serial number M06074.  JCE calculators of other models with low serials are known to have the code letter preceding the serial.  On the right is serial number 506494M.  It is assumed that the M identifies the Mark II model.

The newer of the two JCE Mark II examples came complete with its presentation case (whose red foam is rapidly crumbling) as well as instructions and warranty card.  

One of the interesting things about the JCE Mark II is that the calculator has what would appear to be a battery door on the back, but which is actually the top of a removable battery cartridge or tray.  This comes completely out of the calculator to accept five AA batteries; the tray has contacts which mate with other contacts inside the calculator when properly installed.  As with most early calculators an adapter was available - but it appears that with the JCE, at least, the adapter was an optional extra and not included with the basic purchase.  Below, the battery tray shown in detail.

The whole JCE calculator enterprise appears to have lasted only 1972-1973 or so, from what little can be discerned from the extant materials and advertisements.  In January 1973 the JCE Mark II was being sold mail-order by JS&A for $75.00 with the AC adapter included; by sometime later in 1973 the price had plummeted to $39.95 from the same retailer, again with adapter.  This reflects the incredible pace downward that calculator prices were making and also, not surprisingly, easily shows why many manufacturers could not survive the drops in prices that the truly huge and integrated makers like Texas Instruments could weather.

"Integrated", you say?  That's right.  JCE didn't make any of the really truly important parts of this calculator - the chip, the keyboard, the display.  Possibly not even the circuit board.  Many companies just like this sprang up - with enough new engineering talent, venture capital, some connections and know-how, some marketing and a supply of expensive-to-develop parts made by much bigger companies, dozens of startups flashed briefly on the scene and failed.  Big corporations like TI could weather the temporary losses on calculators until their manufacturing costs were brought in line by sapping profit from other lines; little companies that just made calculators would die soon in deficit.  Others, not integrated, tried to spend money they didn't really have to do things like start making displays or even integrated circuit chips.  Some made it, some failed.  And a couple got in, made money, and got out safely.  JCE?  Well, this company appears to have died as quickly as it started - and today, collectors should keep an eye out for JCE calculators.

   (Above, front and rear print details from instructions found with JCE Mark II s/n 506494M.)

And Here We Go - Calculators!

Another decade - in fact, another century - and another hobby.  My brother Dave and I started collecting early pocket calculators in April of this year and, frankly, we're hooked.  And largely alone.

Not that there aren't some collectors out there - there are a handful.  Astonishingly there has already been formed, operated and completely dissolved an official organization - IACC or International Association of Calculator Collectors.  That association had a newsletter, "International Calculator Collector" and published the only collector book on the subject, "The Complete Collector's Guide to Pocket Calculators."  Citing increasing family demands, the founders disbanded the association years ago and, just like that, official calculator collecting went from extant to extinct.

Yes, there are a couple of small (just around 100) groups on Facebook for collectors, and there are some websites out there; see our website link list in the sidebar.  But in terms of organized collecting, information gathering and so forth - well, if it's happening, it's individual and not being done as a community so far as we can tell.  Serge Devidts has perhaps the most impressive possible website (again, see list) and is still active, and we've noted a couple of other folks out there who seem to be asking for information.  But the free transfer of analysis and history so vital to the real enjoyment of any hobby seems quite sparse in the field of calculator collecting.  We're going to try to fix just a little of that with this blog.

Our plan is to document what we have and what we know.  We'll heavily rely on the references you see mentioned in the side bar boxes as well as our decades of collecting experience in other areas (typewriters, World War 2 weapons, albums, and more) to provide, we hope, some new insight into the exciting if brief early history of calculators. 

Before we get any further let me answer those questions you're trying to ask.  Why would there be interest in these things?

•Probably no advanced technology ever went from military to individual home use faster than the integrated circuit chip - and it did so first in the pocket calculator.

•Pocket calculators went from uber-expensive executive play toys to broadly affordable to cheap inside the span of just about eight years... EIGHT YEARS.  From 1971 to 1978, to be specific. (1)

•There is a fascinating aspect to the rapid rise of these devices, the rapid efforts in many areas to cash in; an entrepreneurial drive often coupled with venture capital to produce dozens and dozens of makes and models of calculators..  which would all COMPLETELY VANISH before the 1970's were over.  Many millions were invested - and many millions were made, but many millions were also lost by many companies.  These stories speak of both innovation and shortcut; they bridge into the studies of engineering as well as marketing. 

•The facts above mean that for the true collector there are unusual and even relatively rare makes and models out there to be found.  Many have been found since the publication of Ball & Flamm (1) in 1997 and have been added to the general knowledge on the internet.  Perhaps more are yet to be found!

•While some makes and models required special adapters, many others operated off disposable batteries, meaning that with cleaning and care the machines MAY still work today.  Many of ours do, but many of ours don't and won't.

•Unlike many other products, in the early days calculator component makers freely sold their parts to other companies.  This mixing and matching of parts, and the free availability of many kinds of components (mainly chips, keyboards, and LED displays) has a great deal to do with the history of the calculator in the 1970's as you'll see play out as we continue the blog.  But for now, look at the photo at the top of this page - four very different makes and models of calculator (from companies that had nothing to do with each other) all of which have Texas Instruments "Klixon" keyboards.  None of the four companies survived the calculator price and production war of the 1970's.

I could go on and on, but instead of further rationalizing I'll simply invite you to come along with us on this blog as we look at the early calculators.  We use the ones that work and test them; you're sure to find some of the results interesting.  NO, they don't all work the same - not by any stretch!  From big to small, simple to scientific - you'll see these devices and their stories here. 

Two Texas Instruments calculators from the 1970's; the TI-30 on the left has an LED (Light Emitting Diode) display, while the TI-150 on the right incorporates an orange vacuum-fluorescent display likely to be a Burroughs Panaplex design. The calculator on the right, according to the Datamath website, is rare - perhaps only 4000 were made.