Mark Wickens

POKE

Purpose

Writes data to a specified address.

Format

POKE      (address)        ,     data
           └──┬──┘               └┬─┘
       Numeric expression    Numeric expression

Example

POKE &H7000, 0

Parameters

1. address: Numeric expression truncated to an integer in the range of -32769 < address < 65536. Negative addresses are added to 65536 and data are written to the resulting address (i.e. POKE(-1) is identical to POKE(65535),data).
2. data: Numeric expression truncated to an integer in the range of 0 ≦ data ≦ 256.

   Explanation

3. Writes data to the specified address in memory.
4. Runaway execution may result if the contents of an address outside the user work area is altered using the POKE statement.
5. The actual address is specified using the DEFSEG statement.

   DEFSEG = 2
   A = POKE &H100, 0
   

   The above does not directly read writet data to address &H100 (256). Instead, 0 is written to the address &H120 (288). (16 x 2 + 256 = 288). Further information of segments can be found under DEFSEG.

See

• PEEK
• DEFSEG

Sample Program

10  DEFSEG=&H0
20  FOR I=&7000 TO &H7010
30  POKE I, 0
40  NEXT I
50  END 

Clears (assigns zeros) memory from 7000ʰ to 7010ʰ.