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Calculators: Desk: Prinztronic XJS (type I)
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Size (approx): | 110mm x 180mm x 50mm (max) (w,h,d) Weight 228g excluding batteries |
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Power: |
4.5V DC, 3 x AA size batteries. Also accepts adapter (4.5V undefined centre positive) through a socket on top side on the far right. | ||
| Case: | Large case with matt black plastic base and silver painted smooth plastic front. The top area is dominated by a tilted and rounded, oversized green plastic display filter with blue and white printed text for the brand and model name. The recessed keyboard has a black gloss finish with reversed out silver and red printed labels. The keys are short travel with a positive click and suffer from bounce on my example. | ||
| Display: | 12 digit green VFD with a thirteenth digit for minus, error and memory indication | ||
| Features: | Standard four functions with square root, percentages, register exchange, change sign and four-function memory. Switched auto-summation memory, rounding and decimal point options. | ||
| Age: | 1975 | ||
| Manufacturer: | Prinztronic, made in Japan, serial number 139218 | ||
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Comments:
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Dixons UK electrical retailer brand name for this bulky calculator that only just fits in the hand - being more destined to sit on the desktop. The display is bright and prominent. The logic is a bit archaic with semi-RPN input, no recovery and several negative zero bugs, but the 12 digits are useful. It appears to be built by Toho. There was a later model Prinztronic XJS type II. |
| Components: | 1 x CPU: Mitsubishi M58623-23P
5729 (a 1975 date code), 28 pin DIL, 0.6" width black plastic 1 x 13 digit VFD unit, single glass tube flat face: itron FG137A6 JHA 1 x transistor 10 x diodes 7 x capacitors 2 x resistors 2 x resistor arrays 1 x transformer |
| Boards: | The complete keyboard (82F 011754) is connected to the main board by a 22-way ribbon cable, that is actually two cables. The main cpu board (TOHO EL-10587-1 CA-0090) sits in the base snugly amongst plastic guides. A second board contains the display. |
| Construction: | Remove the two screws on the back (which will loosen the display filter) and gently lever off the front section and pop the internal lugs. This front section can be removed from the keyboard assembly for better access. |
| Logic comments: | The (CE) button is used to clear last entry and the (C) button clears the whole calculator |
| The logic is semi-RPN (arithmetic) so to work out 5-3 key in (5)(+=)(3)(-=) | |
| There is no constant facility | |
| Overflow on number input is suppressed, keying in a thirteen digit is ignored | |
| Overflow shows zero and "C" in the far left (thirteenth) digit and is not recoverable | |
| Divide by zero shows zero and "C" in the far left (thirteenth) digit and is not recoverable | |
| Memory storage is flagged by the decimal point in the far left ( thirteenth) digit | |
| Overflow in memory flags the overflow and retains the original number | |
| The change sign (+/-) key can be used in mid number entry but not before | |
| Negative square roots are not allowed and show the result with "C" in the far left (thirteenth) digit and is not recoverable. Interestingly the result of a negative square root will always be 12 digits long so that (9)(+/-)(SQRT) will result in "C3.00000000000" | |
| (EX) is used to exchange the last entered number with the one on display in a chain | |
| The auto-summation to memory key [S] will add/subtract every equals key to the memory when switched on | |
| A switch selects between round up [^], round down [v] or round [5/4] when in fixed decimal mode | |
| A switch selects between floating [F] decimal, fixed [0] and [2] decimal points and [ADD] financial mode. The latter will case (2)(3)(4) to be entered as "2.34" for financial use | |
| It suffers the negative zero bug: key in (1)(+=)(2)(-=) to give "-1" now (1)(+=) to give "-0" | |
| It suffers the divide to negative zero bug: key in (1)(+/-)(÷)(1)(0)(+=) and keep dividing by tens until you get "-0" |
