Just trying my skills in MSX-BASIC :-)

MEMDUMP.BAS

10 SA!=&H7DAD:EA!=&H7FFF:COLOR 15,4,4:KEY OFF:SCREEN 0:IF PEEK(&H2D)=0 THEN W%=40:GOTO 20 ELSE PRINT "Display in [4]0 or [8]0 columns?"
15 K$=INPUT$(1):IF K$="4" THEN W%=40 ELSE IF K$="8" THEN W%=80 ELSE 15
20 WIDTH W%:CLS:C%=0:I%=0:J%=0:K%=0
25 IF W%=80 THEN MX%=16:CH%=7:CA%=58:CC%=78 ELSE MX%=8:CH%=5:CA%=29:CC%=38
30 DEF FN H$(I%)=RIGHT$("0"+HEX$(I%),2):DEF FN W$(I!)=RIGHT$("000"+HEX$(I!),4)
40 FOR I!=SA! TO EA!:J%=PEEK(I!):C%=C% XOR J%:IF K%=0 THEN LOCATE 0:PRINT FN W$(I!);
45 LOCATE 3*K%+CH%:PRINT FN H$(J%);" ";
50 LOCATE K%+CA%:IF J%<32 THEN PRINT "."; ELSE PRINT CHR$(J%);
55 K%=K%+1:IF K%=MX% THEN LOCATE CC%:PRINT FN H$(C%);:K%=0
60 IF CSRLIN>22 THEN PRINT "Scroll?";:K$=INPUT$(1):CLS
65 NEXT I!