Friden 1166 Board #2

The #2 logic circuit board in the Friden 1166 is completely unique to the calculator. While there are similarities between 1166 board and the #2 board used in the 1160 and 1162 calculators, the board in the 1166 is more complex, using more ICs. The increased complexity is likely due to the extra logic states required in order to provide for the leading zero suppression on the display, as well as providing fully floating-decimal input. The board has "1166" etched into the upper right-hand corner to positively identify it as only for the 1166 calculator.

The board contains the logic to generate the master clock, and also the chain of flip flops that create the major timing signals used throughout the rest of the logic to choreograph the operation of the calculator.

Board #2 contains a total of 29 integrated circuits, of which twelve are 7400-series TTL devices (made by Texas Instruments or Signetics), with four 7474 Dual D-Type Flip Flops; five 7473 Dual J-K Flip Flops; one 7476 Dual J-K Flip Flops; and one 7400 Quad 2-Input NAND gate chip. The other remaining chips are various DTL ICs, with the exhibit machine having devices made by Motorola (MC8xx-Series) or Texas Instruments (SN158xx-Series). The board also contains three transistors, seven diodes, 13 resistors, and eight capacitors.

The bare circuit board has Friden Part #7016701 Revision 1, and the complete board assembly has Part #7016702.