Try as we may, errors and oversights sneak into our magazine. Our regret takes on useful form in this section, where we will report to you information and corrections that will make past issues of ANTIC more accurate.
In general, you should know that most of the programs that have appeared in ANTIC do run as printed, and that almost all problems reported to us have been due to entry errors on the part of the reader-user. --ANTIC ED
In ANTIC #5 we reported on LJK's Letter Perfect as part of a word-processing system for the ATARI 800 (Model System, p. 18). We used PERCOM Disk Drives in that setup, and implied that there were no problems. Actually, we had encountered, and some readers also reported, a problem formatting data disks for LJK using PERCOM drives.
Both companies confirm this problem. LJK does not use ATARI DOS, nor PERCOM DOS, and formats blank data disks for Letter Perfect using its own DOS, which works fine with ATARI 810 drives, but not with PERCOM drives.
PERCOM's solution is to offer a small program which, when used with its drives, will format blank disks to Letter Perfect specifications. This program is available in hard copy free-of-charge, by writing for the Zero Sector Utility, to Customer Service, PERCOM Data Co., 11220 Pagemill Road, Dallas, TX 75243.
In ANTIC #6, page 78, there is an error in the text accompanying this listing. The next to last paragraph of the article should read, in pertinent part, 'SAVE"C:" rather than 'LIST"C:". Some readers have been confused about how to make a cassette version of this program. Change lines 325 and 330 to read:
325 POKE 764,12
330 RUN "C:CBOOTMGB"
This will invalidate TYPO, so first type-in the program as published, use TYPO to verify your work, then go back and change the lines.
This listing of PAC INVADERS that appeared in ANTIC #3 contained three lines that contained more than 120 characters each. It is possible to enter these lines using the following procedures:
1. Type "POKE 82,0" in the immediate mode, that is, without a line number. This places the left margin at the left edge of the screen, and allows space for two extra characters per line.
2. Omit spaces wherever possible -that is, omit all spaces, and then go back and insert where necessary as indicated by error messages (after entering the line).
3. Use abbreviations for all BASIC keywords. These can be found in Appendix A of your ATARI BASIC Reference Manual.
As long as you can enter a line without getting an error message, the computer will accept it and the line will be placed in the program in full. It doesn't matter if the line LISTS out to over three lines-as long as it was typed in as three or less. However, such lines, after being listed their full length, cannot be edited as normal using the screen editor. In this case, to make any changes in the line, the entire line must be retyped in full, using the aforementioned space-saving techniques.
A line of code was left out of Extended Directory (ANTIC #6). Line 1430 should be inserted as:
1430 MOD .BYTE "dup.SYS"
This allows the routine at line 1280 (label: LOOP1) to change the name of DUP.SYS to dup.SYS, which prevents loading the new DOS with the old utilities package. Incidentally, the last seven bytes in the assembled listing, as published, represent the new name "dup.SYS."
TUT, TUT; UT, UT
In Starting Line (ANTIC #6) there are three errors. In each case a 1 appeared incorrectly where a $ should be. In the first listing change line 40 to read:
40 INPUT #1, TITLE$
In the second listing, lines 20 and 60 should read:
20 PRINT CHR$(125)
60 PRINT CHR$(A);: GOTO 40
We very much regret errors like this in material for beginners.
On page 97 of ANTIC #6, Memory Map should show in location 766 ($2FE) that the hexadecimal value for EOL (end of line) is $9B, not $98.