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Calculators: Handheld: Prinztronic 88P (Dixons)
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Size (approx): | 88mm
(max) x 140mm x 25mm (max) (w,h,d) Weight 152g excluding batteries |
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Power: |
6V DC, 4 x AA size battery, 0.5W. Also accepts adapter/charger (DC 6V, 100mA, centre negative) through top side socket on the right. The battery compartment cover has a small table showing when an adapter/charger can be used; never use an adapter with dry batteries in place. this compartment has a black ribbon to extract batteries. Auto power down function. | ||
| Case: | Solid thick plastic case which is made from a matt/gloss black plastic base and light grey gloss plastic front section. Slightly recessed and flat green plastic display filter. Below this is a black matt plastic keyboard surround. The upper area of this surround has a brushed aluminium sticker, printed black with switch label and brand, which sits in its own recess. The small keys are bouncy with a hollow metallic click. | ||
| Display: | 8 digit green VFD with a ninth digit used for negative, power save and error indication | ||
| Features: | Basic four function with percentages. | ||
| Age: | 1975 | ||
| Manufacturer: | Made in Japan (for Dixons), serial number 644855 | ||
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Comments:
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Well built sturdy calculator that just fits in the hand. The logic is quite good and only let down by the pseudo fixed decimal bug. I presume the model number has an eight in it for the number of digits and a "P" for percentage function (others had "M" for memory). |
| Components: | 1 x cpu: Texas TMS0851NC A7513
(date code week 13 of 1975), 28
pin DIL, 0.6" width black plastic 1 x nine digit VFD unit, single glass tube round face 2 x transistors 2 x diodes 6 x capacitors 11 x resistor 1 x resistor array 1 x transformer |
| Boards: | Construction is depending how you look at it (as the whole assembly sits lose in the case). The keyboard assembly (J CA1905-01[S]) sits on top of the battery compartment and is connected via four metal lugs to the batteries. It also sits above the main, slight warped, cpu board (45-04A) sits face down in the front section. The two are joined by 15 stiff wide wires insulated by some sticky green plastic. A piece of black nylon helps shield the light around the display tube. A small piggy-back board houses most of the power supply components. |
| Construction: | Very very difficult to open as the stiff case sides are held together by sturdy internal lugs. Even though there is a lever slot at the top you are sure to mark this calculator trying to open it - I would advise strongly against it. If you must, use a blunt wooden instrument (like a lollypop stick) on the top slot, whilst pushing in the edge of the front section. Eventually the back will lift off. |
| Logic comments: | The (C) key actually acts as a (CE/C) key: the first press with cancel the last number entered whilst a second press will clear the calculator |
| Overflow on number input is suppressed: keying in a ninth digit is ignored | |
| There is automatic constant on all four functions | |
| Overflow shows the result and "C" (or "E" if negative) in the far left (ninth) digit and is recoverable using (C) | |
| Divide by zero shows zero and "C" in the far left (ninth) digit and is recoverable using (C) | |
| Error is flagged by "C" (or "E" for negative) in the left hand ninth digit with the first eight digits of the answer. Error is recoverable with (C) | |
| Negative numbers are shown with a "-" in the immediate left hand digit, travelling into the far left (ninth) digit, thereby allowing full eight digit negative numbers | |
| There is a power down function. After about 20 seconds the display is blanked and just "-" shows in the far left (ninth) digit, recovery is by pressing (<>) | |
| It suffers the pseudo fixed decimal bug: key in (1)(+)(.)(0)(0)(0)(=) to give "1.000" which remains a three digit decimal number until you need more digits or use multiply or divide |
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This image shows the
front removed and the black nylon light guard also removed.
The main Texas IC is hidden by the keyboard but you can clearly see the extra mini-board with the power supply components next to the transformer. |
