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Pseudocode of SICXE
BEGIN
read first input line
IF OPCODE = 'START' THEN
BEGIN
save #[OPERAND] as starting address
initialize LOCCTR to starting address
write line to intermediate file
read next input line
END {if START}
ELSE
initialize LOCCTR to 0
WHILE OPCODE != 'END' DO
BEGIN
IF this is not a comment line THEN
BEGIN
IF there is a symbol in the LABEL field THEN
BEGIN
search SYMTAB for LABEL
IF found THEN
set error flag (duplicate symbol)
ELSE
insert (LABEL, LOCCTR) into SYMTAB
END {if symbol}
search OPTAB for OPCODE
IF found THEN
add 3 {instruction length} to LOCCTR
ELSE IF OPCODE = 'WORD' THEN
add 3 to LOCCTR
ELSE IF OPCODE = 'RESW' THEN
add 3 * #[OPERAND] to LOCCTR
ELSE IF OPCODE = 'RESB' THEN
add 3 #[OPERAND] to LOCCTR
ELSE IF OPCODE = 'BYTE' THEN
BEGIN
find length of constant in bytes
add length to LOCCTR
END {if BYTE}
ELSE
set error flag (invalid operation code)
END {if not a comment}
write line to intermediate file
read next input line
END {while not END}
write last line to intermediate file
save (LOCCTR - starting address) as program length
END {Pass 1}
BEGIN
read first input line {from intermediate file}
IF OPCODE = 'START' THEN
BEGIN
write listing line
read next input line
END {if START}
write Header record to object program
initialize first Text record
WHILE OPCODE != 'END' DO
BEGIN
IF this is not a comment line THEN
BEGIN
search OPTAB for OPCODE
IF found THEN
BEGIN
IF there is a symbol in OPERAND field THEN
BEGIN
search SYMTAB for OPERAND
IF found THEN
store symbol value as operand address
ELSE
BEGIN
store 0 as operand address
set error flag (undefined symbol)
END
END {if symbol}
ELSE
store 0 as operand address
assemble the object code instruction
END {if opcode found}
ELSE IF OPCODE = 'BYTE' or 'WORD' THEN
convert constant to object code
IF object code will not fit into the current Text record THEN
BEGIN
write Text record to object program
initialize new Text record
END
add object code to Text record
END {if not comment}
write listing line
read next input line
END {while not END}
write last Text record to object program
write End record to object program
write last listing line
END {Pass 2}
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