Table of Contents
Advertisement
Operating and Programming the CDS
25
DBG $A SAMPLE, TTY
FL
LOC
COSMAC CODE
LNNO
SOURCE LINE
0000
RDPTR
=
#3E
.'
.
LOWER HALF READ ENTRY
0000
2
WRPTR
=
#9C
· . LOWER HALF TYPE5D ENTRY
OPOO
3
10
=
R3
·
. UT3 READ·TYPE PROGRAM COUNTER
0000
4
PC
=
R5
· .
CALLING PROGRAM COUNTER
'
0000
5
ARG
=
R6
·
.
POINTER TO IMMEDIATE TYPE BYTE
0000
6
10PTR
=
R7
·
.
HOLDS WRPTR AND RDPTR VALUES
0001
7
ORG #01
·
.
PROGRAM STARTS AT LOC 1
-.
0001
8
...
.....
.. INITIALIZATION PHASE BEGINS HERE
...
.
.
.....
'
0001 90
9
GHI RO
·
.
CLEAR D. SINCE RO.l IS ZERO
0002 B2
10
PHI R2
0003 A2
11
PLO R2
·
.
R2 POINTS AT FREE LOC (ZERO)
0004 B5
12
PHI PC
0005 B6
13
PHI ARG
·
.
CLEAR UPPER HALVES OF LOCAL PTRS
0006 F881
14
LDI #Bl
0008 B3
15
PHilO
·
.
INITIALIZE UPPER HALF UT3 PC
0009 F83E
16
LDI RDPTR
OOOB A7
17
PLO 10PTR
OOOC F89C
18
LDI WRPTR
OOOE B7
19
PHI 10PTR
·
.
LOWER HALVES OF UT3 ENTRI ES
F
OOOF F800
20
LDI A.O (ARG1)
0011 A6
21
PLO ARG
·
.
POINTER TO TYPE
SAVE
BYTE
F
0012 F800
22
LDI A.O (LOOP)
0014 A5
23
PLO PC
·
. LOCAL PROGRAM COUNTER READY
0015 05
24
SEP PC
·
.
SWITCH PROGRAM COUNTERS
0016
25
..
..
...
.
..
MAIN PROGRAM LOOP BEGINS HERE
...
..
.
.
.
.
.
.
.
0016 87
26
LOOPGLOIOPTR
0017 A3
27
PLO 10
· .
POINT TO READ
0018 03
28
SEPIO
·
.
CALL READ
.
FI RST CHAR TO 0
0019 56
29
STR ARG
.
SAVE IT
001A 87
30
GLOIOPTR
001B A3
31
PLO 10
.
REPOINT TO READ
001C D3
32
SEPIO
·
.
CALL READ
.
SECOND CHAR TO D. RF .l
I
001 D E6
33
SEX ARG
..
RESTORE ARG POINTER
..
I
001E F7
34
SM
·
.
SECOND CHAR MINUS FIRST
I
F
001F 3BOO
35
8M TYPE
..
EXIT IF FIRST CHAR IS LARGER
I
1
0021 9F
36
GHIRF
0022 56
37
STR ARG
·
.
SECOND CHAR TO OUTPUT ARG LOC
0023 97
38
TYPE
:
GHI 10PTR
0024 A3
39
PLOIO
· .
POINT TO TYPE5D
0025 03
40
SEPIO
..
CALL TYPE
.
0027
41
ARG1: ORG*+#Ol
·
.
IMMEDIATE BYTE ARG AND SAVE LOC
0027 3016
42
BR LOOP
· .
LOOP FOR ANOTHER PASS
0029
43
END
NO
UNDEFINED LABELS
NO
UNDEFINED SYMBOLICS
DBG
Fig.
5 -
CSDP assembly listing for sample program.
Advertisement
Table of Contents
