... Data Assembly code Comment 20 02 DB FF IN A, (FFH) Get a byte from Port A 20 02 2F CPL Invert the byte 20 03 D3 FE OUT (FEH), A Output the byte to Port B 20 05 C3 00 20 JP 20 00 Go round again Figure ... 16L8 and 22 V10 Figure 11 .2 A Z80 microprocessor Programmable logic controllers Microprocessor systems Programmable logic controllers (PLC) are microprocessor based systems that are used for controlling ... equivalent to decimal 127 Table 11 .2 Data types Data type Bits Range of values Unsigned byte to 25 5 Signed byte G 128 to + 127 Unsigned word 16 to 65,535 Signed word 16 G 32, 768 to + 32, 767 Example 11.1...