Use of an interactive CD-ROM as a learning resource and its effect on student outcome in first year human biology

A microcomputer device contains a CPU with an arithmetic/logic unit and data/address registers on a single semiconductor integrated circuit having on-chip macrocode and microcode storage. A macrocode word is fetched from an on-chip ROM and stored in an instruction register in the CPU, then a sequence of microcode words is fetched from the microcode store based on this macrocode word. A check-code based on some function of all macrocode bits is stored in on-chip ROM upon manufacture. To test a device after fabrication is complete, a test program (resident in ROM or downloaded into on-chip RAM) is executed to address all bytes of macrocode and perform some cummulative function on it via the ALU to see if the same check-code is produced. If so, an output indicates a good unit.