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FADF
F ADF
FADF
FADF C5
FAEO
OE
0 0
FAE2 CD 61
FB
FAE5
FE 16
FAE7 CA F 3 FA
FAEA OC
FAEB C2 E2 FA
FAEE
3E
0 1
FAFO 3 7
FAF1
C l
F A F2 C 9
F AF3
QE
2 0
F A F 5 CD 69
FB
F A F
FE 16
8
FAFA C 2 06
FB
FAFD OD
FAFE C2
F 5 FA
F BO 1 3E
0 2
F BO 3 37
F 3 0 4
C l
FBO 5 C9
F 3 0 6
C l
F 3 0 7
FE
0 2
FB!)9 CA
FB
1 0
F 3 0 C
3 E 03
FSOE
37
FBOF C9
F 3 1 0
CD 69
FS
F B I 3 B9
F S 1 4
DA I E
F3
F 3 1 7
CA I F
FB
F B I A 3E
05
37
FB1C
r B I D C9
F 3 1 E
4F
F B I F A7
F 3
CD
2 0
F 3 2 1
F 3 2 1
F 3 2 1
1 3 2 1
F 5
F 3 2 2 C 5
F 3 2 3
D5
F 3 2 4 A7
r 3 2 5
06
09
F 3 2 7
OE 05
F 32 9 I F
F 3 2A D2
2F ? 3
F 3 2 D
OS OF
F E 2 F A7
? 3 3 0
16
13
F 3 3 2
F 3 3 2
F 3 3 2
F B 3 2
F 3 3 2
F B 3
2
19-30
1 9 9 0
READ H I T
STANDARD BLOCK HEADER.
2 0 0 0
2 0 1 0
READH:
PUSH
MV I
2 0 2 0
2 0 3 0
REAHO:
CALL
2 0 4 0
C P I
2 0 5 0
JZ
2 0 6 0
DCR
2 0 7 0
JNZ
2 0 8 0
MV I
2 0 9 0
STC
POP
2 1 0 0
RET
2 1 1 0
2 1 2 0
REA.H1:
MV I
2 1 3 0
R E A H 2 :
CALL
2 1 4 0
C P I
2 1 5 0
JNZ
2 1 6 0
DCR
2 1 7 0
JNZ
2 1 3 0
MV I
2 1 9 0
STC
POP
2 2 0 0
RET
2 2 1 0
REA R3 :
PGP
2 2 2 0
2 2 3 0
C P I
2 2 4 0
JZ
MV I
2 2 5 0
2 2 6 0
STC
2 2 7 0
RET
2 2 3 0
R E A H 4 :
CALL
'
2 2 9 0
C-!P
2 3 0 0
JC
2 3 1 0
JZ
2 3 2 0
MV I
2 3 3 0
STC
2 3 4 0
PET
MOV
2 3 5 0
R E A H 5 :
2 3 6 0
REAR
:
ANA
6
2 3 7 0
RET
2 3 3 0
2 3 9 0
W R IT E BYTE
IM A TO T A P E .
2 4 0 0
2 4 1 0
W R I T S :
PUSH
2 4 2 0
PUSH
2 4 3 0
PUSH
2 4 4 0
ANA
2 4 5 0
MV I
2 4 6 0
8 I T S 0 :
MVI
2 4 7 0
RAR
2 4 3 0
JNC
M VI
24 90
2 5 0 0
Z E R 0 3 :
ANA
2 5 1 0
M VI
2 5 2 0
. 2 5 3 0
THE FOLLOWING HALF CYCLE LOOP 15 C R I T I C A L L Y T I M E D .
2 5 4 0
S IN C E THE D E S I R E D T R A N S M I S S I O N FPECUENCY I S
2 5 5 0
A FULL CYCLE SHOULD TAKE 5 0 0 U S ,
2 5 6 0
THE LO CF SHOULD TAKE
2 5 7 0
OF 5 0 0 N S ,
SAVE R E G IS T E R TO BE USED
8
C , 0
C W I L L COUNT N O N - S Y N C S
PEADA
TRY TO READ A SYNC CHAR
SYNCH
I S
I T
A SYNC?
REAHl
Y E S ,
PROCEED
C
COUNT DOWN
REAHO
LOO? I F
A ,E R R 1
NO S Y N C 'S
NOTE ERROR
B
PAMPER S T A C "
ABORT
C .N S Y N C
GOT A SY N C ,
RE AD3
READ A BYTE
SYNCH
I S
I T
A SYNC?
PEAH3
N O ,
CHECK I T
C
COUNT DOWN
FRAH2
LOOP I F
A , ERP2
TOO MANY S Y N C 'S
NOTE ERROR
3
TAKE CAPE CF STACK
3
RESTORE BUFFER LENGTH
STXCH
DCES ST Y FOLLOW S Y N C 'S ?
'RE A H 4
Y E S ,
PROCEED
MC,
EP^OF.
A. ERR3
NOTE EPF.OP
ABORT
READS
READ LENGTH OF DATA F I E L D
C
W I L L DATA F I T
REAMS
Y E S ,
E A S I L Y
PEAH
Y E S ,
EXACTLY
6
.A, ERRS
NO ,
RECORD LONGER THAN 3U FF ER
NOTE ERROR
ABORT
C , A
PUT MEW COUNT I N
A
CLEAR CARRY
PSW
•SAVE R E G IS T E R S TO BE U S E D . . .
3
D
A
CLEAP CARRY
B . 2 P C
GET B I T
C , ZPL
SET T I M E R TO ZERO PULSE LENGTH
•CAPPY HOLDS NEXT 3 I T
ZEROG
• S K I P
I F
SET T IM E R TO ONE PULSE LENGTH
C , O P L
RESET CARFY TO I M I T
A
D .HCP BF
GET i
HALF CYCLES PC? S I T
2 5 0 U 3 .
K I T H
THE
LOOP SHOULD CONSUME 5 0 0
«ORE N O N - S Y N C 'S OK
FOUND
GET COUNT ALLOWED
OUT
'-'OPE S Y N C 'S
OK
I N
BUFFER?
C
(R ESE T STOP B I T )
COUNT
TO OUTPUT
B I T
I S
A ZERO
FOR HCYCC
FRA''
2 0 0 0 H Z ,
SO EACH PASS THROUGH
A CLOCK CYCLE T I M E
MACHINE C Y C L E S .
11 - 25
J
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