45SWAP (swap)Calls out a program in the file during execution of the program.Format:SWAP 11 [ name> :] 11Note: Only FDn device name.Abbreviated form:SW.Explanation:• Subroutine calls separate program in file from program being executed. Program inprogram area is temporarily evacuated to vacant area in floppy disk, and calledprogram is read into text area. The original variable in the text area at this time istransferred to the called program. (See page 27.)• An error occurs if a write-protect seal is put on the default drive floppy disk.Example:1 0 A=1: B =22030,--.40PR I NT 11 A = "; A, 11 ~!';~cf}·i:.,·. .,SWAP 11 F D 2 : PRO G'" . j .. "" •11 11 • 11 ./i~~ " "PR I NT A = ,A, B.:=,. 1'~'~ii.~,,~'50 END10 A=A*10:B=B*1020 END(SWAP FD2 PROG)..... When this program is executed, A = 1 and B = 1 are displayed on CRT screenwhen line 20 is executed. At line 30, the SWAP command is executed and theprogram file "PROG" in floppy disk drive 2 is executed. At end, automaticallyreturns to original program, A = 10 and B = 20 are displayed when line 40 isexecuted, and program execution finishes.
