PokeByte bank,offset,value
Parameters
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bank - bank handle returned by CreateBank offset - position in the bank to write to, in bytes (0 = first byte) value - value to store; only the low 8 bits (0-255) are kept |
Description
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Writes a byte into a bank. Only the low 8 bits of the value are stored, so 0 to 255 survive exactly and anything else is wrapped (poking -1 stores 255). PeekByte reads it back. Offsets are range checked - writing outside the bank raises a runtime error instead of trashing memory. See also: PeekByte, PokeShort, PokeInt, PokeFloat. |
Example
; PokeByte Example ; ---------------- ; A player save-game record packed into a memory bank. ; Field sizes: byte=1, short=2, int=4, float=4 bytes. ; ; offset 0 flags (byte, 1 byte ) ; offset 1 hp (short, 2 bytes) ; offset 3 score (int, 4 bytes) ; offset 7 x_pos (float, 4 bytes) = 11 bytes in total save=CreateBank(11) ; Pack the record - PokeByte writes the 1-byte flags field ; at offset 0 (values 0-255); the other Pokes fill the rest PokeByte save,0,5 PokeShort save,1,250 PokeInt save,3,1234567 PokeFloat save,7,17.25 ; Unpack the record - each Peek reads its field back Print "Player record in a "+BankSize(save)+" byte bank:" Print "" Print "offset 0 flags (byte) = "+PeekByte(save,0) Print "offset 1 hp (short) = "+PeekShort(save,1) Print "offset 3 score (int) = "+PeekInt(save,3) Print "offset 7 x_pos (float) = "+PeekFloat(save,7) ; Dump every byte so the layout is visible ; (ints and floats are stored low byte first) dump$="" For i=0 To BankSize(save)-1 dump$=dump$+PeekByte(save,i)+" " Next Print "" Print "Raw bytes: "+dump$ ; Release the memory when done FreeBank save Print "" Print "Press any key to close the example" WaitKey End
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