BASIC POKE and DOKE Statements

POKE

TYPE: BASIC System statement

FORMAT: POKE address , byte

Action: The POKE statement is used to write a one-byte (8-bits) binary value into a given memory location.

address is an expression which can be reduced to an integer in the range of -65535 to 65535.
byte is an expression which can be reduced to an integer in the range 0 to 255.
An Illegal Quantity error occurs if either argument is out of its respective range.

Examples of POKE Statement:

POKE 12329,65

Puts an "A" at position 1 on the screen. POKE 36879,8 Puts 8 into memory location 36879

plusBASIC enhancement

FORMAT: POKE address , string

Action: As above but writes string expression string to memory starting at address.

plusBASIC enhancement

FORMAT: POKE @ page , address, byte

Action: This syntax writes a one-byte (8-bits) binary value into a given memory location in a specified page .

The page specifies the RAM page to write to. It is an expression which can be reduced to an 8-bit integer. The allowed pages are:
- 20 for Video RAM
- 21 for Character RAM
- 32 to 63 for main RAM
address is a numeric expression which must be in the range of 0 to 16383.
byte is an expression which can be reduced to an integer value of 0 to 255.
An Illegal Quantity error occurs if any argument is out of its respective range.

plusBASIC enhancement

FORMAT: POKE @ page , address , string

Action: As above but writes string expression string to memory starting at address.

TYPE: BASIC System statement

FORMAT: DOKE address , word

Action: Same as above, but writes a two-byte (16-bits) binary value.

word is an expression which can be reduced to an integer in the range -65535 to 65535.
- The low byte of value is written to the specified address and the high byte is written to the following address.
An Illegal Quantity error occurs if either argument is out of its respective range.

FORMAT: DOKE @ page , address, word

Action: Same as above, but writes a two-byte (16-bits) binary value.

word is an expression which can be reduced to an integer in the range -65535 to 65535.
- The low byte of word is written to the specified address and the high byte is written to the following address.
- If address is 16383 (the last byte of the page), the high byte is written to address 0 of the following page.
  - An Overflow error occurs on an attempt to write to the last byte of pages 20, 21, and 63.
An Illegal Quantity error occurs if any argument is out of its respective range.