Big Man Computer

This article is not detailed enough and needs to be expanded. Please help us by adding some more information.

There are one thousand memory cells in each bank, each storing a decimal number from 0000 to 9999. The accumulator also stores number from 0000 to 9999 and also has a negative flag and zero flag and carry flag.

Instructions:

• 0xxx: Halt. The xxx is irrelevant.
• 1xxx: Add value from memory cell xxx to accumulator. Zero and negative and carry flags set according to result.
• 2xxx: Subtract value from memory cell xxx from accumulator. Zero and negative and carry flags set according to result.
• 3xxx: Store value of accumulator in memory cell xxx.
• 4xxx: Branch to xxx if carry flag is clear.
• 5xxx: Load value in memory cell xxx into accumulator. Zero flag set according to result.
• 6xxx: Unconditional branch to xxx.
• 7xxx: Branch to xxx if zero flag is set.
• 8xxx: Branch to xxx if negative flag is clear.
• 9xx0: Swap low three digits of accumulator with program counter, and swap data in bank xx with the data in the current program bank. Flags are not affected.
• 9xx1: Read input from port xx into accumulator. Zero flag set according to result.
• 9xx2: Output value of accumulator to port xx.
• 9xx3: Select program bank xx. Program counter remains unchanged.
• 9xx4: Select data bank xx.
• 9xx5: Swap memory of bank xx with the memory of the current data bank.
• 9xy6: Swap program bank selection with data bank selection if either digit x or y is in the accumulator.
• 9xx7: Multiply accumulator by ten and add xx. Flags are not affected.
• 9xx8: Divide accumulator by one hundred and shift in xx. Zero flag is set according to shifted out digits.
• 9xy9: If x is zero, set carry flag. If y is zero, complement carry flag. If x is one, set zero flag. If y is one, complement zero flag. If x is four, set negative flag. If y is four, complement negative flag.