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01F0-PRINT-STRING.md

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01F0 Print string

Print a NULL-terminated string whose address is in [BX]. This is used by the system library to print internal strings and error messages.

SYS01F0: CS:
SYS01F1: MOV AL,[BX]
SYS01F3: OR AL,AL
SYS01F5: JZ 01FD
SYS01F7: CALL 0232
SYS01FA: INC BX
SYS01FB: JMP 01F0
SYS01FD: RET

This will load one character at a time from [BX], then call the print character service in SYS:232. It will continue printing a character until a NULL (00h) byte is encountered. The strings it prints must be located within the system library's code segment.

Because it returns with a NEAR RET, it can only be called from within the system library.

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