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Calculators: Handheld: Commodore SR4120D
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Size (approx): | 80mm
x 150mm x 40mm(max) (w,h,d) |
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Power: |
9V through 1 x PP3 battery. The adapter (640 or 7076 for N America, 708 England and 709 West Germany) is used through a socket on the top side, in the middle. It is recommended that you remove the battery if using an adapter. | ||
| Case: | Large, tilted and bowed case made from textured black plastic. The heavily inset, tilted and flat red plastic display filter gives a clean bright image though with a narrow angle of view. A section at the top has a raised and (originally painted silver) brand name. Bold coloured keys in red, blue, grey and white are quite small, squishy and wobbly. The front outer edge was also originally painted silver but has worn on my example. | ||
| Display: | 12 digit red LED module with bubble lens, 8+2 scientific notation | ||
| Features: | Standard four functions and trig functions, transcendental functions, pi, change sign, reciprocal, register exchange, polar/rectangular coordinates, degree/radians, powers, nth root, square root, squares, brackets, statistics (mean and standard deviation), double memory (one is three function, the other two function). | ||
| Age: | 1978 | ||
| Manufacturer: | Commodore, Made in England. Serial No. 122427 | ||
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Comments:
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With 48 keys is this a button monster or what! The SR (Slide Rule) prefix of this period indicates a scientific model. This is one serious calculator, although the "Made in England" means assembled at best as all the components and boards are Japanese. It appears to use the same IC as the contemporary SR4190R but with less additional components and a great many functions missing. |
| Components: | 1
x CPU: MOS MPS 7200 4377 (week 43 of 1977), 40 pin DIL 0.6" width 1 x IC: MPS7000 042 0278 ( week 2 of 1978),16 pin DIL 0.3" width 2 x IC: ITT 546A-5N 7739 display driver (date code week 39 of 1977) 16 pin DIL 0.3" width 1 x 12 digit LED module with individual bubble lens 1 x resistors 1 x capacitors |
| Construction: | Opened with two screws on the back (lower end being hinged. Very densely packed inside, despite the size. Thick ribbon cable joins the three boards. The display board is held in place by the upper power socket and two moulded forks on the back. |
| Boards: | Three boards; main board (Rev-C 200794 ITTOc) sits above the, keyboard assembly (GIKO K-1 GK-459 53.2.9 (date code 1978 February 9)). The latter is fixed to the front with eight screws and a card separator keeps the main board from touching. |
| Logic comments: | Sample not yet working |
