Advertisement
Not a member of Pastebin yet?
Sign Up,
it unlocks many cool features!
- APAL - A Processor Assembler Language
- INTRODUCTION
- An APAL program is composed of one or more APAL source statements.
- Each statement is one line in length. Each statement, when com-
- piled by the APAL compiler, results in one or more instructions to
- be executed by the A processor, or the definition of working memory
- space for the program. The APAL compiler examines each source state-
- ment for proper syntax and usage of operands. Any errors are noted
- on the compile listing which is a product of the compilation process.
- The compiler generates instructions, assigns memory addresses, and
- sets aside memory areas for buffers and working space as directed by
- the source statements in the program.
- The console command to execute the APAL compiler is: APAL A B C.
- A is the name of the file containing the source program. B is the
- name of the file that will contain the binary at the completion of
- the compilation process. C is the name of the file that will contain
- the listing.
- STATEMENT FORMAT
- The basic APAL instruction takes the form of a conditional assignment
- statement.
- Label Assignment Expression , Condition Expression .Comments
- #
- Subject1 = Expression1, Subject2 = Expression
- <
- >
- Except for a very limited number of statements, all APAL source
- statements take this form. The assignment portion of the statement
- is always present, and is composed of a single subject followed by an
- = sign followed by an expression which expresses the value of the
- quantity which is to replace the subject operand. The = sign is the
- only separator allowed between the subject and the replacement ex-
- pression in the assignment portion of the statement. Expression1 may
- be any expression composed of valid names ond operators. The condition
- portion of the statement is optional. When present, it is first eval-
- uated to determine a true or false condition. If true, the assignment
- portion of the statement is executed. If false, the assignment portion
- of the statement is not executed. If
- [file broken from here]
Advertisement
Add Comment
Please, Sign In to add comment
Advertisement