The Motorola MC14500B is a single chip, one-bit static CMOS processor optimized for decision-oriented tasks. The processor is housed in a 16-pin package and features 16-four-bit instructions. The instructions perform logical operations on data appearing on a one-bit bidirectional data line and data in a one-bit accumulating Result Register within the ICU. All operations are performed at the bit level.
See more in MC14000B INDUSTRIAL CONTROL UNIT HANDBOOK.
This GAL (ATF16V8B...) version of the MC14500has an original instruction set, but it has some differences:
Data is read from a separate DI input and written to a separate DO output during GAL's clock rise, at the time of instruction execution. This unit does not have usually unused pins RET, FLG0, FLGF (but they are easily to implement each by external single logic gates).
GAL and reprogrammable ATF SPLDs can be easily programmed by afterburner.