6502 Shorts

6502 Shorts. By Lee Davison.

Introduction.

This section is for those short bits of code that are just what you need every now and then.
Anything longer than $20 bytes should probably be elsewhere.

The code.

Toggle carry - Change the sense of the carry bit. BCD to binary - Convert a BCD byte to binary.

Range test - Test a byte is in the range n to m. Binary to BCD - Convert a binary byte to BCD.

Check CMOS - Test if code is running on a 65C02. Hex to ASCII - Another way to convert a hex nibble.

Save XY - Push/pull X & Y without using A. Eight bit rotates - One bit less in ROL or ROR.

ASL & ASR - A true arithmetic shift left and right. Sign extend - Extending a less than 8 bit value to 8 bits.

Last page update: 23rd April, 2006.

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Toggle carry	- Change the sense of the carry bit.	BCD to binary	- Convert a BCD byte to binary.
Range test	- Test a byte is in the range n to m.	Binary to BCD	- Convert a binary byte to BCD.
Check CMOS	- Test if code is running on a 65C02.	Hex to ASCII	- Another way to convert a hex nibble.
Save XY	- Push/pull X & Y without using A.	Eight bit rotates	- One bit less in ROL or ROR.
ASL & ASR	- A true arithmetic shift left and right.	Sign extend	- Extending a less than 8 bit value to 8 bits.