1. Suppose the machine described in Appendix C communicates with a printer using the technique of memory-mapped I/O. Suppose also that address FF is used to send characters to the printer, and address...

1.
Suppose the machine described in Appendix C communicates with a printer using the technique of memory-mapped I/O. Suppose also that address FF is used to send characters to the printer, and address FE is used to receive information about the printer’s status. In particular, suppose the least significant bit at the address FE indicates whether the printer is ready to receive another character (with a 0 indicating “not ready” and a 1 indicating “ready”). Starting at address 00, write a machine language routine that waits until the printer is ready for another character and then sends the character represented by the bit pattern in register 5 to the printer.