DECPKFMR—Program Key Free Memory Report
Report the approximate free memory space for program key operations.
denotes the total memory space in bytes that is reserved for the programmable keys. The total memory available is 804 bytes, hence the Ps1 value is "804."
denotes the memory space that is available at the time DECRQPKFM is received, depending on the number of bytes left in decimal format. A "0" indicates that no memory is left for any key programming operation; in which case, any attempt to program the keys will fail.
The VT510 reports this sequence upon receiving DECRQPKFM from the host.
Note on DECPKFMR
The free bytes reported by Ps2 in this command represents only the approximate amount of memory available, because additional memory is used by the firmware data structure to program the key definitions.