If you want to use a specific assembly language routine, learn assembly language quickly, or improve your programming skills, 6502 ASSEMBLY LANGUAGE SUBROUTINES is for you. It provides code for more than 40 common 6502 subroutines, including code conversion, array manipulation,arithmetic, bit manipulation, string processing, input/output, and interrupts. It describes general 6502 programming methods (including a quick summary for
experienced programmers), and tells how to add instructions and addressing modes. It even discusses common 6502 assembly language programming errors.

This book identifies strengths and weaknesses of the 6502 instruction set, and allows you to make instant use of 6502 assembly language. You can use these subroutines to

• Run a specific routine.
• Speed up a BASIC program.
• Assist in programming an I/O driver, a diagnostic, a utility, or a systems program.
• Quickly learn 6502 assembly language programming (based on your knowledge of another microprocessor).
• Improve your programming skills by seeing examples of working routines and the shortcuts used.
• Debug, maintain, or revise an existing program.