Pass 1 flowchart

1. Macro Processors
Flowcharts
Pass 1-Processing macro definitions
Pass 2-Processing macro calls and expansion

2. MACRO
pseudo-
op?
Pass 1
MDTC<-1
MNTC<-1
Enter line into MDT
Substitute
index
notation for
arguments
Go to Pass 2
Write copy of
source card
Read next
source card
MNTC <- MNTC + 1
Enter macro name and
current value of MDTC
in MNT entry number
MNTC
Read next
source card
Prepare argument list array
Enter macro name card
into MDT
MDTC <- MDTC + 1
END
pseudo-
op?
MEND
pseudo-
op?
Read next
source card
MDTC <- MDTC + 1
Yes
Yes
Yes
No
No
No
Pass 1 – processing macro definitions

3. Pass 2 – processing macro calls and expansion
MACRO
name
found?
Pass 2
Supply expanded
source file to
assembler
processing
Write into
expanded
source card
file
Read next
source card
(copied by
pass 1)
MDTP <- MDTP + 1
Set up argument list
array
MDTP <- MDT index
from MNT entry
Get line from MDT
Substitute arguments
from macro call
END
pseudo-
op?
MEND
pseudo-
op?
Write
expanded
source card
Yes
Yes
Yes
No
No
No
Search MNT for match
with operation code