bool

1-bit integer

char

8-bit signed or unsigned integer

short [int]

16-bit signed or unsigned integer

int

System-specific width integer (32-bit in ELLO 1A)

long [int]

32-bit signed or unsigned integer

long long [int]

64-bit signed or unsigned integer

float

32-bit floating point

double

64-bit floating point

long double

80-bit or wider floating point
(supported in C.impl but not supported in ELLO 1A)

In addition to the basic types above, several other data types are also supported

size_t

Natively represented as unsigned int

enum

Standard enumeration list, evaluated as int values

struct

Standard C-type data structure

union

Standard C-type data union

va_list

In conjunction with <stdarg.h> for argument lists

FILE

File handler for standard <stdio.h> library functions