ANITA Desk Calculators Using LSI Integrated
Power supply - AC mains.
Printer version of the ANITA 1233D. Printed output, 12 columns. The impact printer is from the company which became Epson.
4-functions, square root, three memories.
Uses six LSI (Large Scale Integration) integrated circuits from Rockwell, see photograph of 'Logic Board' below.
210 mm x 300 mm x 170 mm (8.25" x 11.8" x 6.7").
Made in England by Sumlock Anita Electronics Ltd, distributed by Sumlock Comptometer Ltd.
The keyboard of the ANITA 1233P. The keys for the three memories are on the right.
To replace the printer ribbon the holder is released upwards.
Here the top cover has been removed to reveal the printer at the top and the key pad circuit board. The printer is from the
Note about the printer
The impact printer is from Shinshu Seiki Co., Ltd. of Japan, whose name was changed to Epson Corporation in 1982, and merged to Seiko Epson Corporation in 1985. These small drum printers were created out of development work that Shinshu Seiki did for the Seiko Group when they became the official time-keepers for the 1964 Tokyo Olympic games. The first of these printers was the EP-101, which was released in September 1968. This and similar models were used in a number of printing calculators from several manufacturers around this time. Subsequent printers were given the trade name Epson, 'son of EP', or 'EP-son'.
The printing mechanism is based around a horizontal metal print drum which has a row of the digit 0 raised across it, below which is a row of the digit 1, followed by a row of digit 2, and so on to 9, and then several rows of various symbols. The print drum spins continuously when the machine is powered up and printing is performed by a linear array of solenoid activated hammers which momentarily hit the ribbon and paper against the appropriate digits on the drum as they pass by. John Wolff has a more detailed description of the printing mechanism in his analysis of the Compucorp 155 "Surveyor" Desk Calculator, which uses a similar printer.
The keyboard has been hinged up to reveal the neat arrangement of circuit boards which plug into sockets for easy servicing. At the top is the 'POWER BOARD' date stamped November 1973. Note that the base is die-cast aluminium, strong enough to support the heavy printer which weighs 2.5Kg.
Unplugging the Power Board reveals the 'Keyboard Interface' board. This board carries discrete electronic components: 28 transistors (grey squares with 3 leads), 58 diodes (mainly tiny blue thin cylinders), many resistors (with multicoloured stripes) and a handful of capacitors (mainly blue of various shapes).
At the bottom is the 'Logic board' with large-scale integrated (LSI) circuits manufactured by Rockwell (carrying date codes year/week):
10563PC (7335), 10180PA (7325), 10177PA (7308)
15023PD (7336), 10179PB (7307), 10178PA (7307)
From the rear, showing the AC transformer and the printer.
From the rear showing the power supply capacitors and the printer.
The label on the underside of the ANITA 1233P.
Advertisement for ANITA 1233P (Printing version) and 1233D (Display version), from April 1973.
Here is an Operating Manual for the ANITA 1200P Range of Calculators, including the ANITA 1233P.
See also the ANITA 1233D, a version which has a display instead of the printer.
Anita Desk Calculators Using LSI Integrated Circuits
Text & photographs copyright © 2002 - 2022 Nigel Tout, except where noted otherwise.