Edmund Scientific 1945

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Edmund Scientific 1945
& similar models

Similar tiny calculators with a rechargeable battery pack which plugs directly into the AC supply. There are differences in detail between the battery packs but these all appear to have been manufactured by the same, unknown, company.

Edmund Scientific 1945
Alcor Grand Prix
Monte Carlo
UIT 85X
Unknown Model
Unknown Scientific Model
Cybio 004m - a slightly larger model.

Edmund Scientific 1945

Display is 8 digits, red LED.

4-function, %.

Integrated circuit - probably Texas Instruments TMS0803NL, see UIT 85X below.

Size 52 x 90 x 14 mm. (2.0" x 3.5" x 0.55").

About 1975.

Manufactured in Hong Kong.

This is a noticeably tiny calculator, but the novel feature is that the battery pack unplugs from the calculator and plugs directly into the 110V AC supply.
The body of the battery pack measures 36 x 48 x 8 mm () and contains rechargeable button cells.

Edmund Scientific is a U.S. mail-order supplier of scientific instruments and components.

Further down this page are similar models.

After sliding up the back cover the rechageable battery pack is revealed. This can be unplugged from the calculator and plugged straight into the AC supply for recharging.

Alcor Grand Prix

Alcor Grand Prix.

This model has a triangular battery pack.

Inside, the calculator is marked "Made in Hong Kong".


	Here the battery pack has been unplugged and removed from the rear of the calculator.


	Monte Carlo

Monte Carlo

This model has a triangular battery pack.

Made in Hong Kong.

With the rear casing slid up to reveal the battery pack.


	The cover and the battery pack have been completely removed. The brown coating on the integrated circuit is adhesive from the insulating tape which covered the electronic components.


	The rechargeable button cells can be seen through the translucent casing of the battery pack.


		UIT 85X



	UIT 85X Display is 8 digits, red LED. 4-function, %. Integrated circuit - Texas Instruments TMS0803NL (here date coded week 23, 1975). Size 52 x 90 x 14 mm. (2.0" x 3.5" x 0.55"). About 1975. Probably manufactured in Hong Kong.


	The rear of the calculator with the back cover slid up so that the battery pack can be unplugged for recharging.

The battery pack has been unplugged from the calculator, and shows the two prongs for plugging directly into a U.S. type 110V AC power outlet.

The rear cover of the calculator has been completely removed to reveal the minimal electronics in this machine.


	Unknown model

Unknown model.

These photographs of a similar calculator without a name were kindly provided by Juan Luis de la Peña


	Here the rear has been removed to reveal the battery pack, which is a different shape to that of the UIT 85X, above. Being made of opal plastic allows us to see the five rechargeable button cells inside.


	Showing the very compact electronics into which the battery pack plugs.

Unknown Scientific Model

This is a similar model to those above but additionally has scientific functions. This appears to be a partly assembled calculator kit, but some components, including keys, have been lost.
The operating instructions illustrate the display as 8 digits which changes to scientific mode for very large or small numbers with 5 digits mantissa and 2 digits exponent.

Cybio 004m

Display is 8 digits, red LED.

4-function, %, memory, square root.

Integrated circuit - Rockwell A5902CA (here date coded week 12, 1976).

Size 56 x 103 x 15 mm. (2.2" x 4.1" x 0.6"). This calculator is a little bigger than the other models illustrated here, as can be seen in the photograph above right where it is compared with the Monte Carlo.

About 1976.

The power pack here is designed to be plugged into a 230v AC outlet for recharging.