VIDEO 80 For Atari
Brad Brooks points out that the 80-column software from the April issue (p. 170) can be restarted after a SYSTEM RESET without having to power up again. Simply type ?USR(9013). You'll get an ERROR 9 message, but this does not affect program operation.

Match-Em
This game for the TI in the April 1983 issue (p. 123) has a minor flaw. Hitting the same key twice will register as a valid match. Our thanks to reader James Alessio, for suggesting the following fix:


TI Air Defense
The confusing characters at the beginning of line 1950 of the TI version of this game (page 46 of the April issue) should be replaced with the command PRINT.

Atari CRAB
This Atari BASIC cross-reference program from the April issue (p. 188) has problems when handling inverse video characters or USR codes in quotes. To prevent this, reader David Butler suggests adding the following line:

245 IF C=15 THEN GOSUB GC FOR J=I TO C:GE
     T #I,G:NEXT J:GOSUB GC

Also, some printers add a carriage return after LPRINT;. To correct this, David offers the following modifications:

390 OPEN #I,8,Z,"P:":PRINT #I;"XREF FOR "
     ;A$
420 D=INT(LN/H):M=LN-H*D:IF NOT M THEN PR
     INT #I:PRINT #I
430 PL=PEEK(X+T):FOR J=5 TO PL-T:PRINT #I
     ;CHR$(PEEK(X+J));:NEXT J
440 PRINT #I;" ";:IF NOT M THEN PRINT #I
460 PRINT #I:PRINT #I:PRINT #I;D-L+I;" VA
     RIABLES"

Apple Subroutine Capture
In the text for the EXEC file (Program 1, page 171) of this article from the March issue, be sure that the word "RUN" appears (without a line number) as the last line in the file or the program will not operate properly.

VIC Data Acquisition
In the program on page 248 of the May 1983 issue, the POKE 37166,128 in line 20 should be replaced with POKE 37166,64.

ZX-89/TS-1000 Data Management
Line 2065 of this program from the March 1983 issue (p. 230) should read:


Color Computer Version Of Vehicle Cost Performance
In line 770 (February 1983, p. 164), the WRITE#1 should be PRINT#1. In line 1160 the CLD should be CLS. In line 1250, the "GALLONS";Y should be "GALLONS",Y.

Commodore Maze Generator Enhancement
The maze generating program by Charles Bond reprinted in the February issue (p. 106) has a shortcoming. The fixed order of the elements in the A(3) coordinate array generates mazes that almost invariably spiral counterclockwise around the screen. Neil Murray suggests stirring in a little randomness by adding the following line:

115 FOR I=3 TO 1 STEP -1:K=INT(RND(I)*I):
     SV=A(K):A(K)=A(I):A(I)=SV:NEXT I

Automatic Commodore Program Selector
The programs which accompany this article from the March 1983 issue (p. 156) require modification to work with the VIC-20 and 1540/1541 disk drive. All output to the screen should be adjusted for the 22-column display. Line 290 of Program 1 and line 470 of Program 2 should be changed to:


In Program 3, delete line 420 and make the following changes:

210 DIM AE$(150)
240 PRINT:PRINT:PRINT"READING{2 SPACES}D
    RIVE 0"
250 PRINT"{DOWN}PROGRAMS FOUND: 0"
290 IF C$=CHR$(220) THEN 410
350 PRINT"{UP}"TAB(17)AN-A0
440 MM=9:PRINT"{CLR}{RVS}PROGRAM MENU #"
    STR$(MN+1)"{OFF}{DOWN}"
460 PRINT TAB(3)"{RVS}"RIGHT$(STR$(I),1)
    "{OFF} "MID$(AE$(MN*9+I),3,16)"
    {DOWN}"
470 NEXT:PRINT"{RVS}MAKE A CHOICE OR
    {OFF}"
480 PRINT"{RVS} PRESS 'RETURN' {OFF}"
590 PRINT"RUN":PRINT"RUN":PRINT"{HOME}
    {7 DOWN}";

For the Commodore 64 with 1541 drive, delete line 420 and make the following changes to Program 3:

210 DIM AE$(150)
290 IF C$=CHR$(199)THEN 410