Control panel for 3niti alpha consists of 2 rows:

• Top horizontal row of 15 "ternary" red-green light indicators:
  • Lights 1,2,3,4,5,6,7,8,9 (A8...A0) - value of PC register (address of current operation)
  • Lights 10,11,12 (D2...D0) - 3-trit data (see below)
  • Lights 13,14,15 (Register A) - current value of A register
• Bottom horizontal row of 15 "ternary" slide switches:
  • Switches 1,2,3,4,5,6,7,8,9 (A8...A0) - some 9-trit address entered by user
  • Switches 10,11,12 (D2...D0) - some 3-trit data entered by user
  • Switch 13 (W/R) - control input/output ternary switch:
    • P (top position) - using specified address write data to the memory (data lights display this 3-trit data)
    • O (neutral position) - ignore address and data switches (data lights display data from memory address PC)
    • N (bottom position) - ignore data switches and display data from specified address
  • Switch 14 (I/M) - control subprogram ternary switch:
    • P (top position) - interrupt main program, save current PC and jump to specified address
    • O (neutral position) - do not disturb working program
    • N (bottom position) - stop subprogram and restore PC to return to main program
  • Switch 15 (S/G) - control step/run ternary switch:
    • P (top position) - execute one step of the program
    • O (neutral position) - pause mode
    • N (bottom position) - run program from current position