--- /dev/null
+.387
+ PUBLIC MXWRITEPLANE
+ PUBLIC MXREADPLANE
+MX_TEXT SEGMENT PARA PUBLIC USE16 'CODE'
+ ASSUME CS:MX_TEXT, DS:DGROUP, SS:DGROUP
+MXWRITEPLANE:
+ push bp
+ mov bp,sp
+ sub sp,0
+ mov ah,byte ptr 6[bp]
+ and ah,0fH
+ mov al,2
+ mov dx,3c4H
+ out dx,ax
+ mov sp,bp
+ pop bp
+ retf 2
+MXREADPLANE:
+ push bp
+ mov bp,sp
+ sub sp,0
+ mov al,4
+ mov ah,byte ptr 6[bp]
+ and ah,3
+ mov dx,3ceH
+ out dx,ax
+ mov sp,bp
+ pop bp
+ retf 2
+MX_TEXT ENDS
+ END