The .db and .byte statements are used to define
a series of 8 bit data byte values. The values must be in the range 0 to
255. The .db keyword will also convert an ASCII string into a sequence
of binary values
syntax:
[<label>] .db <expr> [, <expr> [, <expr> ...]]
[<label>] .byte <expr> [, <expr> [, <expr> ...]]
e.g.
.db 1,2,3
.db "hello world",0
MSG_START .db MSG_END - (MSG_START + 1)
.db "another message"
MSG_END
BEWARE: defining bytes in the code section of a CPU that
has a program counter that counts in words may cause the location counter
to be incremented to an odd address. Also note that the length of a block
of data will be reported as half the expected size. This will not affect
the data stored, just the observed length.