Casio FX-603P

• Name — CASIO FX-603P • Type — Programmable scientific • Entry — Infix • Manufacturer — Casio • Introduced — 1990 • Precision — 12 digits mantissa, ±99 exponent • Display Type — LCD Dot-matrix • Display Size — 2×16 Character • Memory Data — 110 • Memory Step — 6,144 • Prog Lang — Keystroke (fully merged, Turing complete) • Conn1 — Compact Cassette • Via1 1 — FA-6 • Conn2 — Line Printer • Via2 1 — FA-6 • Via2 2 — Centronics printer port • Conn3 — PC • Via3 1 — FA-6 • Via3 2 — RS-232 • Ports — one vendor specific • Supply — 2×"CR-2032" Lithium + 1×"CR-2032" Lithium • Weight — 141g, 5 oz • Dimensions — 15.24x7,6x1.2 cm, 6"×3"×½"

The FX-603P featured a two line dot matrix display with 16 characters each as main display. An additional 4 digits 7-segment display used to display the program step when entering or debugging programs and 20 status indicators.

The programming model employed was 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. There were only a very few operations which needed two bytes. The FX-603P could store 6,144 steps. Data could be stored in 110 memory register. The FX-603P series supported 20 labels for programs and subroutines called P0.. P19 - twice the amount of the predecessor models. Each program or subroutine could have up to 10 local labels called LBL0.. LBL9 for jumps and branches. The FX-603P supported indirect addressing both for memory access and jumps and therefore programming model could be considered Turing complete. The FX-603P was backward-compatible with the FX-602P could load FX-602P programs from Compact Cassette.

Here is a sample program that computes the factorial of an integer number from 2 to 69. For 5!, you'll type 5 P0 and get the result, 120. With the additional alpha output the program is 14 byte long. • Key-code — Comment • MODE — Change to mode 2 to enable editing of program areas P0 to P19 • From the program list, press P0 button to start editing the program area P0 • ALPHAALPHA — output "n!=" in first row of display. Result will be shown in 2nd line • waits for user input, user types in number and presses EXE button to continue program • stores the value typed in by the user in register M00 • put 1 in current immediate register so there is a value to multiple with • label for the loop • multiply • by n • GOTO — decrements M00 and back to LBL0 until M00=0 • end of loop, the machine has calculated 1 \times n \times (n - 1) \times \cdots \times 2 \times 1 =n!

• Name — Casio FA-6 • Type — Multi Interface • Manufacturer — Casio • Conn1 — Compact Cassette • Via1 1 — Line-Out: 3.5 mm TRS connector • Via1 2 — Mic-In: 3.5 mm TRS connector • Via1 3 — Tape Start/Stop: 3.5 mm TRS connector • Conn2 — Line Printer • Via2 1 — Centronics printer port • Conn3 — Personal computer • Via3 1 — RS-232C The FX-603P used the same FA-6 interface as used by the Casio FX-840P, Casio FX-841P, Casio FX-850P, Casio FX-860P, Casio FX-860Pvc, Casio FX-870P, Casio FX-880P, Casio FX-890P, Casio VX-1, Casio VX-2, Casio VX-3, Casio VX-4, Casio Z-1 and Casio Z-1GR programmable calculator and pocket computers. This interface features a Kansas City standard Compact Cassette interface, a Centronics printer port and a RS-232 interface.