Floating Point

BASIC Plus

F,4

32 bit IEEE float

AlphaBASIC

F,6

48 bit AMOS float

BASIC Plus

F,8

64 bit IEEE float

Binary, little endian

AlphaBASIC

B,1

8 bit unsigned

B,2

16 bit unsigned

B,3

24 bit unsigned

B,4

32 bit unsigned

B,5

40 bit signed (two's complement)

A-Shell

B,6

48 bit unsigned

I,6

48 bit signed (two's complement)

Integer, AMOS format

BASIC Plus

I,1

8 bit signed (two’s complement)

I,2

16 bit signed (two’s complement, little-endian)

I,4

32 bit signed (two’s complement, 2301 order)

String

AlphaBASIC

S,#

fixed length string of # bytes [AB]

A-Shell

S,0

variable length string (dynamically sized, always with trailing null)

Unformatted
(raw bytes)

AlphaBASIC

X,#

fixed length raw bytes

(none)

May be declared implicitly by leaving type,size specifier in MAP statement blank and defining lower-level MAP statements.

Multi-level MAPs

AlphaBASIC

MAP1 CUST
    MAP2 NAME,S,30
    MAP2 CUSNO,B,4
    MAP2 TOTSALES,F,6

1, 2

Defined Structures

A-Shell

DEFSTRUCT ST_CUST       ! define structure layout
    MAP2 NAME,S,30
    MAP2 CUSNO,B,4
    MAP2 TOTSALES,F,6
ENDSTRUCT
...
MAP1 CUSREC,ST_CUST    ! define instance of structure
...
READ #CH, CUSREC       ! read/write entire struct at once
? CUSREC.NAME          ! use structvar.member notation for fields