VIC20-ASM-003 Print Character on Screen

slot the VICMON cartridge into your VIC20
start VICMON by entering: SYS 24576

We want to accomplish the following:

• start program at 1400 and load the row coordinate of the lower screen border (#$16) into the X register 
• load the column coordinate of the right-most screen border (#$15) into the Y register
• call the set cursor location (Plot) subroutine at address $FFF0
• load the value for letter W (#$57) into the accumulator
• run subroutine ($FFD2) to output the W character (#$57) from the accumulator to screen
• end the program

test the program from VICMON by entering: .G 1400

the result will be a W character in the lower-right corner of the screen. As VICMON updates, the W character will scroll upwards by 5 rows.

you can now play with other coordinates and other characters.