| size (optional) - size of the bank in bytes; 0 (default) |
|
Creates a memory bank - a raw block of bytes you can read and write at any offset. Banks are the tool for binary data: building custom file formats (load a whole file with ReadBytes, pick it apart with the Peeks), packing network packets, passing structures to DLLs with CallDLL, or just storing lots of values more compactly than arrays allow. A new bank starts filled with zeros, and offsets run from 0 to BankSize-1. The value types you can Peek and Poke are: Byte : 1 byte, values 0 to 255 Short : 2 bytes, values 0 to 65535 Int : 4 bytes, values -2147483648 to 2147483647 Float : 4 bytes Values can sit at any byte offset - no alignment rules - but every access is range checked, so peeking or poking outside the bank raises a runtime error instead of corrupting memory. In Extended mode there are also Long and Double variants (8 bytes each); see the wide numbers reference. See also: FreeBank, BankSize, ResizeBank, PokeByte, ReadBytes. |
; CreateBank 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
; CreateBank reserves an 11 byte block of memory for the record
save=CreateBank(11)
; Pack the record - each Poke writes its field at a byte offset
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