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Calculators: Handheld: Alco Alcor 888
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Size (approx): |
80mm x 144mm x 20mm (w,h,d) Weight 122g excluding batteries. |
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Power: |
4.5V DC with 3 x AA size batteries. It accepts an adapter (DC420) through a socket on the top side to the right. The battery compartment lid is held by a single screw and there is a (very long) black ribbon pull to aid battery removal, which is definitely needed as one of the batteries sits deep inside the compartment. | ||
| Case: | Slab-shaped design in glossy and matt two piece plastic case. A neutral display filter has a painted window and sits flat in its own raised escutcheon which, as this is recessed, sits flush with the sides. Above this the on/off switch has its own raised lettering. The keyboard surround is recessed even more with individual raised areas reminiscent of Commodore designs. The small keys are medium travel with a strong bounce back. A black printed metallic label sits in its own raised recess with the model number. | ||
| Display: | 8 digit blue VFD with a ninth digit for negative and error indicators. | ||
| Features: | Four function with percentages and square root | ||
| Age: | 1975 | ||
| Manufacturer: | Alco Marketing, Flushing, New York, made in Korea, serial number 5123827 | ||
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Comments:
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Rather plain design that looks a bit bottom heavy due to the battery compartment area being blank from the front. Striking resemblance to Commodore-type keys. The logic is not so good with negative zero bug and lack of any recovery. The original cover is soft black plastic with flip over top flap and front tuck-in section that looks big enough to accommodate a manual. Similar to the Unitrex Executron 830 and uses the same IC with different functions available. |
| Components: | 1 x cpu: Hitachi HD36290
5B21 (February 1975)
28 pin DIL , 0.6" width black plastic 1 x 9 digit VFD unit, single tube round face 2 x transistors 6 x diodes 6 x capacitors 22 x resistors 1 x transformer |
| Boards: | The keyboard assembly (HM-20-11-RM5 KB-6367-01 XEC) is fixed to the front with seven screws. It is joined to the main cpu board by 14 flying coloured wires. The transformer sits in its own cut-out to reduce the overall thickness. |
| Construction: | Remove the battery compartment cover and then the four screws at the rear (two shorter ones inside the battery compartment). Gently separate the two halves as there is a mess of wires inside. |
| Logic comments: | The (CE) key is used to cancel number entry whilst (C) clears the whole calculator |
| Overflow on the input of a number is suppressed, keying in a ninth digit is ignored | |
| There is automatic constant on all four functions | |
| Negative numbers are flagged by a "-" sign in the far left (ninth) digit thereby allowing full eight digit negative numbers. | |
| Overflow shows the result with a "C" (or "E" if negative) in the far left (ninth) digit and is not recoverable | |
| A divide by zero shows zero and "C" in the far left (ninth) digit and is not recoverable | |
| Negative square roots are not allowed and show the result with "E" in the far left (ninth) digit and is not recoverable | |
| It suffers the negative zero bug: key in (1)(-)(2)(=) to give "-1" then (+)(1)(=) to give "-0" | |
| It almost suffers the divide to negative zero bug: key in (1)(-)(=) to give "-1" then (/)(1)(0)(=)(=)(=) etc. to eventually give "-0" then one more equals will give "0" showing the internal extra digit of precision |
