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pedant

SHOWOUT MARC A, B, C, D, E; macros are called to display strings at specified coordinates and attributes.
MOV AH, 13H; where the string is defined in ES
MOV AL, 0H
MOV BH, 0H
MOV BL, D
MOV CX, E
MOV DH, A
MOV DL, B
MOV SI, OFFSET C
MOV ES: [BP], SI
INT 10H
ENDM

SHOWOUT 08,32, MESS1,0B9H, LENTH1; DH / DL = 08/32, MESS1 is the displayed string, 0B9H is
In doing so, it shows how it can be garbled.

www_james

...
; MOV SI,OFFSET C
; MOV ES:[BP],SI
MOV BP, C; ES:BP points to the string to be displayed, not the address of the string
INT 10H
...

pedant

No, the book says so. It should be the only address, otherwise bp is in ss by default.

www_james

es:bp is the address of the string to be displayed, not the address