Writing Relocatable
Subroutines in
Machine
Language
64
In
the
tape
system,
the
first two of
the
preceding items are reversed
and
ap-
pear as individual records, i.e.,
the
first record contains a flag zero
and
the
second
record contains
the
next even
number
above
the
number
of locations used
by
the
subroutine.
The
last
card
of
the
relocatable subroutine section
of
the
subroutine
deck contains a flag one
(I)
in column
62
and
the
sequence
number
26000 in
columns
76
through 80. This
card
follows
the
last trailer
card
and
indicates to
the
relocator
that
all relocatable subroutines have been processed.
In
the
paper
tape
system, this record
is
a single one
(1).
If
a relocatable subroutine is written
in
machine language,
the
origin
and
oper-
ation code flags
must
be
as described for writing in sps.
The
card
format must
also conform to
the
condensed sps as follows:
Instruction
Card
Columns 1-61
62
65-69
70-74
76-80
Constant
Card
Columns 1-61
62
65-69
70-74
76-80
One
to five instructions
with
operation codes flagged for
relative P or Q addresses. A record mark
must
be
in col-
umn
61
or
must
immediately follow
the
last instruction
on
the
card
(the
record
mark
is
not
loaded
at
object
time).
Instructions must use
the
full 12 digits.
If
packing
is done,
the
Q field must still
be
filled
with
zeros
and
the
packed
instructions would
start
a
new
card.
o (zero-instruction
card).
Storage address where column 1 of
the
card
will load.
(High-order digit
must
be
flagged.)
Address of next storage location
beyond
the
number
of
locations used
by
the instruction. (High-order digit must
be
flagged.)
Sequence number.
Constants which will
be
loaded
sequentially into memory.
A record
mark
must
be
in column
61
or immediately fol-
lowing
the
last digit of a constant on the card. Consecu-
tive constants terminated
by
record marks
must
be
on
individual cards with double record marks
at
the
end.
1 (one-constant
card).
Same as instruction card.
Address of next core location
beyond
number
of locations
used
by
constants. (High-order digit
must
be
flagged.)
Sequence number.
In
the
paper
tape
system,
an
absolute language version of a relocatable
subroutine
must
be
in
the
same form as
output
by
the
paper
tape
version of
1620 sps.
In
the
card
system,
the
subroutine relocator checks sequence numbers upon
reading.
If
a
card
is missing or
out
of order,
the
error message
CARD
OUT
OF
SEQUENCE
will
be
typed.
In
this case
you
must
restore the
proper
sequence
and
then
push
the
start
key.
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