RS R/W DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 === === === === === === === === === === 0 1 BF A A A A A A A
Reads Busy flag (BF) indicating internal operation is being performed and reads address counter contents
Details
Reads the busy flag (BF) that indicates the system
is now internally executing a previously received
instruction. BF = 1 indicates that internal operation
is in progress. The next instruction will not be
accepted until BF is set to "0". Check the BF status
before the next wire operation.
At the same time, the value of the address counter expressed in AAAAAAA is read out. The address counter is used by both CG and DD RAM addresses. Its current use is determined by the previous instruction.