# Multiply 8-bit value by 16 and store as a 16-bit value
This is used in NES games (at least [[Faxanadu]]) to take a value and turn it into a ROM offset for a 16-byte span.
For this:
* Input:
* `A` = Starting value
* Output:
* `A` = Low byte of value
* `tempvar` = High byte of value
```asm
LDA value
LDY 0
STY tempvar
ASL value
ROL tempvar
ASL value
ROL tempvar
ASL value
ROL tempvar
ASL value
ROL tempvar
CLC
```