0 REM << CD43-7 >>
1 REM ==================================
2 REM  COMMODARES PROBLEM #39-3 :
3 PRINT"[147]    [194]INARY [208]OWER 3"
4 REM  SOLUTION BY
5 REM     RUSSELL K PRATER
6 REM  SCREEN CHARACTER REVERSAL
8 REM =====  C-64 ONLY  ================
9 REM  SELECT ADDRESS FOR CHARACTER RAM
10 ADDR=12288 : POKE 252,ADDR/256
19 REM   PROTECT IT FROM BASIC
20 POKE 56,ADDR/256 : CLR
29 REM   CODE IS RELOCATABLE; CHANGE ML
30 ML=820 : IF PEEK(ML)<>169 THEN GOSUB 110
39 REM   DOWNLOAD AND REVERSE ROM
40 SYS ML : P=PEEK(53272)
49 REM   REDIRECT VIC CHIP
50 POKE 53272,(P AND 240)+12
59 REM   PRESS ANY KEY TO RESTORE
60 GET A$ : IF A$="" THEN 60
70 POKE 53272,P
79 REM    PRESS ANY KEY TO REVERSE
80 GET A$ : IF A$="" THEN 80
90 GOTO 50
100 END
110 FOR I=ML TO ML+55:READ A:CK=CK+A:POKE I,A:NEXT:IF CK=7701 THEN RETURN
120 PRINT"ERROR IN DATA":END
130 DATA 169,(null)15,133,255,169,000,133,251
140 DATA 133,253,169,208,133,254,120,165
150 DATA 001,041,251,133,001,16(null),000,177
160 DATA 253,162,007,010,102,002,202,016
170 DATA 250,165,002,145,251,200,208,239
180 DATA 230,252,230,254,198,255,016,231
190 DATA 165,001,009,004,133,001,088,096