Early Electronic Calculator Victor 18-3441 Calculator

Manufacturer:  Victor Model:  18-3441 Year:  1971 Form:  Desktop Functions:  Basic four, user memory Number of Digits:  14 Display Type:  PRI Logic Technology:  LSI-7 Diodes:  67 (17+4+23+23) Transistors:  45 (20+2+23) IC Complement: Rockwell 10177 NA, Rockwell 10178 PA, Rockwell 10179 NB, Rockwell 10180 PA, Rockwell 10306 NA, Rockwell 10307 NB, Rockwell 15020 NA (7 total) Tech. Data Level:  1.9 Tech. Data Source:  RE Tech. Data Pages:  1 Tech. Data: Schematic (pdf)

I suspect the LSI chip-set utilised in this calculator is an example of Rockwell's first version of the PPS4 processor series. This speculation is based on some correlations with ICs from the later PPS4/2 version.

Internal view. Upper half of case removed.	Print mechanism and insulating separator between mechanism and logic board removed.	Lower half of the case with the print mechanism and circuit boards removed.
Upper half of the case with keyboard.	The logic board with the Rockwell chipset.	Logic board solder side.
Driver board. The reddish-brown transistors are integrated darlington pairs to drive the print solenoids.	Driver board solder side.	Power supply board.
Power supply board solder side.	The print mechanism. The mechanism appears to have been in some measure adapted from that of a mechanical calculator. There is a solenoid for every digit. In operation, a print cycle is initiated, the solenoids are then triggerred at a point in time to select the numeral to be printed for that digit. All the heavy work is performed by the motor, the solenoids are quite small.	Mechanism left side with power connections for motor.
Mechanism right side. The timing wheel and optical sensor send pulses to the logic to time the triggerring of the solenoids for numeral selection.	Rear of the mechanism with a view into the area where the solenoids are located.	The mechanism was OEM manufactured by a German company.