Expression of Variables and Programs
Expression of Decimal Numbers
Decimal numbers are represented using 8 bytes to accommodate values within the range: [-9.999999999 \times 10^{99}, + 9.999999999 \times 10^{99}]
Byte Structure
- 1st Byte: Exponent (binary format, can be negative)
- 2nd Byte: Mantissa sign (00H for positive, 80H for negative)
- 3rd to 7th Bytes: Mantissa value within [-9.999999999, + 9.999999999]
- 8th Byte: Reserved (always 00H)
Expression of Binary Numbers
Binary numbers use 8 bytes, though only 3 bytes are active (5th, 6th, and 7th) within the range: [-32768, +32767]
Byte Structure
- 5th Byte: Reserved (B2H)
- 6th to 7th Bytes: Binary number value
- 1st to 4th, 8th Bytes: Invalid data
Expression of Character Strings
Character string information is composed of 8 bytes, where only 4 bytes are used. The character string information resides in the address specified.
Byte Structure
- 5th Byte: Reserved (D0H)
- 6th to 7th Bytes: Leading address (0000H to FFFFH)
- 8th Byte: Size of the string (01H to 50H)
- 1st to 4th Bytes: Invalid data
Structure of Variable Names
Variable names consist of two bytes representing 2 ASCII characters and contain bits to distinguish between numeric and non-numeric variables, with support for array assignments.
Bit Structure
- 1st to 8th bits: First ASCII character
- 9th bit: Array assignment (1 for arrays, 0 otherwise)
- 10th bit: 7th bit of the ASCII code (least significant byte)
- 11th bit: Indicates if the variable is numeric (0) or non-numeric (1)
- 12th to 16th bits: Second ASCII character (low-order bits)
Structure of Program Lines
Each line in the program consists of a line number, line size, code, and an end code (0DH).
Byte Structure
- 2 Bytes: Line number
- 1 Byte: Line size
- Variable Bytes: Program code
- 1 Byte: End code (0DH)
