One facility which the Commodore 64 lacks is the PRINT AT command. There are several ways of simulating this command on the Commodore 64, however.

Perhaps the simplest method is as follows:

10 REM SIMULATION OF PRINT AT L,C,Z$
20 REM LINE L, COLUMN CL1<=L<25,1<=C<=40
30 POKE 214,1:POKE 211,C-1:PRINT CHR$(145);Z$
40 REM OR POKE 214,1:PRINT CHR$(145);TAB(C-1);Z$
50 REM FOR PET CHANGE 214 TO 216 AND 211 TO 198

 
Note that cursor up, CHR$(145), is required (Try removing it!) and that TAB should only be used if the previous PRINT did not terminate in a semi-colon (Again, try it!).

It is worth reminding Pet, Vic and 64 users of a bug in Commodore Basic. Typing a line number in the range 350720 to 353279 should result in a "?SYNTAX ERROR", but in practice various responses are possible, ranging from an effect similar to pressing RUN/STOP RESTORE on the 64 (or jump to the monitor in the Pet), to an irrevocable crash.

Finally, two tips relating to the use of cassettes on the Vic and Commodore 64.

An idea of the number of dropouts which occurred on reading a tape can be gleaned from PEEK(158): a value of 4 or less is usually not significant. The filename of the last cassette read or write operation can be inspected with the aid of FOR T=833 TO 839:PRINT CHR$(PEEK(T));:NEXT

Nick Higham
Eccles, Manchester