V25 Memory & String-Packing Commands

V25 extends V24 with low-level memory access, binary string packing/unpacking, and string-array manipulation.

Memory Access

POKE

Syntax: POKE address, value

Writes a single byte to a memory address.

LOCAL x AS LONG, p AS QUAD
p = VARPTR(x)
POKE p, 66    ' Write byte 66 to x

POKE$

Syntax: POKE$ address, string$

Writes a block of bytes from a string to a memory address.

LOCAL buf AS STRING * 32
POKE$ STRPTR(buf), "ABCD"

PEEK

Syntax: PEEK(address)

Reads a single byte from a memory address. Returns a numeric value.

x = PEEK(VARPTR(var))

Binary String Packing (V25)

Pack numeric values into fixed-size binary strings for random file I/O.

Function	Packs To	Bytes
`MKBYT$(n)`	BYTE	1
`MKI$(n)`	INTEGER	2
`MKL$(n)`	LONG	4
`MKDWD$(n)`	DWORD	4
`MKQ$(n)`	QUAD	8
`MKS$(n)`	SINGLE	4
`MKD$(n)`	DOUBLE	8
`MKE$(n)`	EXT	10
`MKCUR$(n)`	CURRENCY	8
`MKCUX$(n)`	CUX	8

packed = MKL$(123456) + MKS$(1.5)
PUT #1, 1, packed

Binary String Unpacking (V25)

Function	Unpacks From	Bytes
`CVBYT(s$)`	BYTE	1
`CVI(s$)`	INTEGER	2
`CVL(s$)`	LONG	4
`CVDWD(s$)`	DWORD	4
`CVQ(s$)`	QUAD	8
`CVS(s$)`	SINGLE	4
`CVD(s$)`	DOUBLE	8
`CVE(s$)`	EXT	10
`CVCUR(s$)`	CURRENCY	8
`CVCUX(s$)`	CUX	8

GET #1, 1, packed
x = CVL(LEFT$(packed, 4))

String Helpers (V25)

NUL$

Syntax: NUL$(n)

Returns a string of n zero (null) bytes.

DEC$

Syntax: DEC$(n)

Returns the decimal string representation of a number (like STR$ but without leading space).

String-Array Commands (V25)

JOIN$

Syntax: JOIN$(array$(), delimiter$)

Joins all elements of a dynamic STRING array into a single string, separated by the delimiter.

REDIM arr(1 TO 3) AS STRING
arr(1) = "a" : arr(2) = "b" : arr(3) = "c"
PRINT JOIN$(arr(), ",")    ' "a,b,c"

SPLIT

Syntax: SPLIT source$, delimiter$ INTO array$()

Splits a source string by delimiter into a dynamic STRING array. Array is automatically REDIM'd.

REDIM parts(1 TO 1) AS STRING
SPLIT "one,two,three", "," INTO parts()
' parts(1)="one", parts(2)="two", parts(3)="three"

MID$ Statement

Syntax: MID$(target$, pos [, n]) = value$

In-place substring assignment. Replaces characters in the target string without changing its length.

s = "abcdef"
MID$(s, 2, 3) = "XYZ"    ' s = "aXYZef"

Note: MID$ assignment performs in-place replacement and does not grow the target string. If value$ is shorter than the replacement range, remaining characters keep their original values.

V24 String Commands (Included in V25)

V25 includes all V24 string-completion commands: REPEAT$, STRDELETE$, STRINSERT$, STRREVERSE$, BIN$, OCT$, LTRIM$, RTRIM$, REPLACE$, SCAN$, TALLY, VERIFY, COMMAND$, ENVIRON$, CURDIR$, TAB$, PEEK$, INPUT$, INKEY$, WAITKEY$.