The programming model employed
key stroke programming by which each key pressed was recorded and later played back. On record, multiple key presses were merged into a single programming step. Only a few operations needed two bytes.
Synthetic programming was possible but not very common. The
FX-601P could store 128 fully merged steps and data could be stored in 11 memory register. The memory of the
FX-602P could be partitioned between somewhere from 32 to 512 fully merged steps, and data could be stored in 22 to 88 memory register. The default set-up was 22 register and 512 steps. From there one could trade 8 steps for one additional register or 80 steps for 11 register with the 11th register begin a so-called "F" register. Like its predecessor, the FX-602P series supported 10 labels for programs and subroutines called P0 .. P9. Each program or subroutine could have up to 10 local labels called LBL0 .. LBL9 for jumps and branches. The
FX-601P and
FX-602P supported
indirect addressing both for memory access and jumps and therefore the programming model could be considered
Turing complete. Both the FX-601P and FX-602P could load and execute programs from their predecessors.
Programming example This program computes the factorial of an integer number from 2 to 69. For 5!, the user enters 5 P0 to produce the result, 120. The program occupies 9 bytes of memory. ==Interface==