The UM6502/UM6507/UM651 microprocessors are totally software compatible with one another. These products provide a wide selection of addressable memory range, interrupt input options and on-chip clock oscillators and drivers. The UM6502/UM6507 on-chip clock versions are aimed at high performance, low cost applications where single phase inputs or crystals provide the time base. The UM6512 external clock version is geared to multiprocessor system applications where maximum timing control is mandatory. These products are bus compatible with the MC6800.