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05-03-89/T\TTX00
This website contains an archive of files for the Acorn Electron, BBC Micro, Acorn Archimedes, Commodore 16 and Commodore 64 computers, which Dominic Ford has rescued from his private collection of floppy disks and cassettes.
Some of these files were originally commercial releases in the 1980s and 1990s, but they are now widely available online. I assume that copyright over them is no longer being asserted. If you own the copyright and would like files to be removed, please contact me.
| Tape/disk: | Home » CEEFAX disks » telesoftware14.adl |
| Filename: | 05-03-89/T\TTX00 |
| Read OK: | ✔ |
| File size: | 4494 bytes |
| Load address: | 0000 |
| Exec address: | FFFFFFFF |
File contents
Interfacing with the Acorn Teletext Adaptor - by - Gordon Horsington
--------------------------------------------------------------------
Module 0. Introduction
----------------------
This module introduces a block of eight modules which deal with the Acorn
Teletext Adaptor. The techniques described in this module also apply to
other adaptors which use a BBC Enterprises ATS ROM (such as the Morley
adaptor) and to the GIS ATS+ ROM, but the techniques described in modules
1 to 7 can only be used with the Acorn adaptor.
The eight modules are in files named T/TTX00 to T/TTX07. The following
topics will be covered in these modules.
Module 0. This module. Introduction and extending the ATS.
Programs: SCROLL SUBTITL
Module 1. Teletext generated interrupts.
Program: COUNTER
Module 2. The Teletext header packet.
Program: HEADER
Module 3. Designing a simple Teletext frame grabber.
Program: GRABBER
Module 4. Designing a simple Teletext keyword search utility.
Programs: KEYWORD
Module 5. Independant Data Services, Channels 0 to 7, Part 1.
Program: TSDP0
Module 6. Independant Data Services, Channels 0 to 7, Part 2.
Program: TSDP2
Module 7. Independant Data Services, Channels 8 to 15.
Program: DATCAST
The later modules develop the ideas and techniques described in the
earlier modules and for this reason they need to be worked through from
beginning to end rather than used as a reference guide. Before starting
you should read and understand either the ATS User Guide or the TFS User
Guide. It would be helpful if you have worked through the ATS course
modules previously broadcast on BBC Telesoftware, but this is not
essential. It is essential to have either BASIC 2 or BASIC 4 installed in
your computer.
When testing the programs associated with modules 1 to 7 I found that with
one particular sideways RAM / shadow RAM board installed in the BBC B
they would not work properly. The older types of sideways RAM/ROM board
(such as ATPL Sidewise) don't cause any problems. If you experience any
problems you should alter all references to the secondary interrupt vector
(irq2v at &206) to the primary interrupt vector (irq1v at &204). If a
program will still not run then disable the ATS with *NOTTX or *UNPLUG. If
this does not work then I suggest that you complain to the manufacturer of
the sideways RAM / shadow RAM board.
After completing the Teletext modules you might find the following
publications a useful source of additional information.
1) Broadcast Teletext Specification, September 1976.
Published jointly by the BBC and IBA.
2) World System Teletext and Data Broadcasting System, August 1987.
Published by Department of Trade and Industry, London SW1E 6SW.
I should like to thank Jeremy Brayshaw and Peter Vince both of whom have
given me access to the information used to write these modules.
--------------------------------------------
Extending the facilities provided by the ATS
--------------------------------------------
The Teletext terminal is entered using the command *TELETEXT and the
terminal is controlled using the computer keyboard. If you look at the ATS
function key strip you will see that there are three shifted function keys
which are not used by the terminal. These are Shift+f5 (ATS up to version
2.58 only), Shift+f8 and Shift+f9. If any of these shifted function keys
is pressed while in the Teletext terminal mode then the ATS issues an
unrecognised function key Osword call. The unrecognised function key
Osword call can be trapped and either two or three unused shifted function
keys (depending on the ATS version number) can be used to call up machine
code programs which extend the range of facilities offered by the ATS
terminal mode.
Osword calls are made with the accumulator containing the Osword call
number (in this case &7A) and the X and Y registers contain the address of
the Osword parameter block.
All Osword calls are passed through the Osword indirection vector at &20C
and &20D. This vector can be re-directed to point to a new routine which
can recognise the unrecognised function key and use it to call a new
machine code routine. The code used to re-direct the Osword indirection
vector and recognise a function key is shown in figure 1 below.
.install
LDX &20C \ osword vector low byte
LDY &20D \ osword vector high byte
CPY #newcode DIV 256 \ is the vector already modified?
BEQ return \ return if already altered
STX oldvector \ save the original osword vector, low byte
STY oldvector+1 \ and high byte
LDX #newcode MOD 256 \ low byte of new code
LDY #newcode DIV 256 \ and high byte
STX &20C \ alter osword vector, low byte
STY &20D \ and high byte
.return
RTS
.newcode
CMP #&7A \ all ATS osword calls use osword &7A
BNE jump \ branch if not from ATS
STX &70 \ X and Y point to the parameter block
STY &71 \ store them for post-indexed indirect addressing
LDY #&00 \ index to point to first parameter
LDA (&70),Y \ read first parameter
CMP #&A0 \ &A0 = unused function key
BNE exit \ branch if not unused function key
INY \ point to second parameter
LDA (&70),Y \ read second parameter
CMP #&15 \ shift+f5, ATS unused function key
BEQ shiftf5 \ branch if shift+f5 pressed (ATS 2.58)
CMP #&18 \ shift+f8, ATS unused function key
BEQ shiftf8 \ branch if shift+f8 pressed (ATS and ATS+ 2.00)
CMP #&1C \ shift+f8, ATS+ unused function key
BEQ shiftf8 \ branch if shift+f8 pressed (ATS+ 1.00)
CMP #&19 \ shift+f9, ATS unused function key (ATS and ATS+)
BEQ shiftf9 \ branch if shift+f9 pressed
.exit
LDA #&7A \ restore accumulator
LDY &71 \ restore Y
.jump
JMP (oldvector) \ exit using the original osword vector
.oldvector
NOP \ store original osword vector, low byte
NOP \ store original osword vector, high byte
.shiftf5
\ new shift+f5 routine goes in here
RTS
.shiftf8
\ new shift+f8 routine goes in here
RTS
.shiftf9
\ new shift+f9 routine goes in here
RTS
Figure 1. Intercepting Osword &7A:&A0
-------------------------------------
All ATS Osword calls, including the unrecognised function key call, use
Osword &7A. The Osword parameter block used by the unrecognised function
key call contains two bytes. The first byte is &A0, which indicates an
unrecognised function key, and the second byte is either &15, &18, &19 or
&1C (&15 is only used by ATS versions up to 2.58 and &1C is only used by
ATS+ 1.00). If the second byte contains &15 this indicates that Shift+f5
has been pressed (ATS 2.58), &18 is used with Shift+f8, &1C with Shift+f8
(ATS+ 1.00), and &19 with Shift+f9.
The routine in figure 1 is installed by calling the memory location
labeled 'install'. This replaces the original Osword vector with a new
vector which points to the code labeled 'newcode'. The original vector is
saved in the two memory locations labeled 'oldvector'. When an Osword call
is issued it will be vectored to the newcode instead of the original code,
and the newcode can recognise the unrecognised function key call.
There are a number of important points to look at in figure 1. First of
all the install routine checks to see if the new code is already
installed. If the new code has been installed the program exits without
attempting to alter the Osword vector. When the new code is installed it
must not be installed a second time until after the Break key has been
pressed. If it is installed a second time, all Osword calls, other than
the ATS unrecognised function key call, will get into an endless loop and
hang up the computer.
The new routine does not completely replace the standard Osword code. If
an Osword call is not the Osword &7A unrecognised function key call the
routine restores the original registers and exits with an indirect jump to
the original vector. The JMP (oldvector) instruction allows all other
Osword calls to be processed as they were before the new routine was
installed.
If an ATS unrecognised funtion key call is intercepted the new routines
labeled shiftf5, shiftf8 and shiftf9 completely replace the original code
and, after executing the new routine, an exit is made with an RTS
instruction and not an indirect jump to the original code.
Any new routine used by the ATS terminal must be assembled into an area of
user memory which is not used by the ATS. If you are using a disc filing
system you can use the cassette output and input buffers (pages &09 and
&0A) and, on the BBC B, you could consider using page &0C which is not
used in mode 7. Page &0C is used for Econet workspace on the Master series
computers and may also be available to the ATS. The demonstration program
SCROLL is assembled into page &0A but this can be changed by altering the
value of mcode in line 80.
The program SCROLL is used to enlarge and scroll a part of the Teletext
page displayed by the terminal. Install the program by either *RUNning the
object code or chain the source code and press return when prompted for a
filename for the object code. Then type *TELETEXT to enter the terminal
mode. When a page is displayed press Shift+f8 to enlarge the top half of
the page to fill the screen. Press Shift+f9 to scroll the window downwards
and Shift+f8 to scroll it back up. If you are using ATS version number
2.58 (or less) then press Shift+f5 to restore the original window. The
original window will also be restored if you try to scroll down beyond the
last line (all versions of ATS and ATS+).
If double height characters are displayed on the screen you may have to
press either Shift+f8 or Shift+f9 twice to make sure that both halves of
the double height characters on the top and second lines are in the
displayed window. If only the lower half of the characters are displayed
on the top line of a screen which uses a lot of double height characters
the window looks quite confusing even though the interpretation of the
characters is correct.
10 REM> SCROLL
20 A%=&EA : REM : read Tube presence flag
30 X%=0
40 Y%=&FF
50 IF ((USR(&FFF4)AND&FF00)DIV&100)<>0 END
60 zeropage=&70 : REM : 2 byte workspace
70 wordv=&20C : REM : osword indirection vector
80 mcode=&A00 : REM : machine code at &A00
90 addreg=&FE00 : REM : 6845 internal register select register
100 intreg=&FE01 : REM : 6845 internal register data register
110 oswrch=&FFEE
120 osbyte=&FFF4
130 FOR pass=0 TO 2 STEP 2
140 P%=mcode
150 [ OPT pass
160 .firstbyte
170 LDX wordv \ osword vector low byte
180 LDY wordv+1 \ osword vector high byte
190 CPY #newcode DIV 256 \ is the vector already modified?
200 BEQ return \ return if already altered
210 STX oldvector \ save the original osword vector, low byte
220 STY oldvector+1 \ and high byte
230 LDX #newcode MOD 256 \ low byte of new code
240 LDY #newcode DIV 256 \ and high byte
250 STX wordv \ alter osword vector, low byte
260 STY wordv+1 \ and high byte
270 LDA #&16 \ decimal 22
280 JSR oswrch
290 LDA #&07
300 JSR oswrch \ mode 7
310 .screenaddr
320 LDA #&0D \ decimal 13
330 STA counter \ initialise line counter
340 LDA #&A0 \ read VDU variable value
350 LDX #&50 \ offset &50 points to start of screen
\ address
360 JSR osbyte
370 STX lsb \ X contains low byte
380 TYA \ Y contains high byte, to be modified in
\ Mode 7
390 CLD
400 SEC
410 SBC #&74 \ by subtracting &74
420 EOR #&20 \ and EORing with #&20
430 STA msb \ Mode 7 modified high byte
440 .return
450 RTS
460 .newcode
470 CMP #&7A \ all ATS osword calls use osword &7A
480 BNE jump \ branch if not from ATS
490 STX zeropage \ X and Y point to the parameter block
500 STY zeropage+1
510 LDY #&00 \ index to point to first parameter
520 LDA (zeropage),Y \ read first parameter
530 CMP #&A0 \ &A0 = unused function key
540 BEQ unused \ branch if unused function key
550 LDA #&7A \ restore accumulator
560 LDY zeropage+1 \ restore Y
570 .jump
580 JMP (oldvector) \ exit using the original osword vector
590 .unused
600 INY
610 LDA (zeropage),Y
620 CMP #&15 \ 21 = shift+f5, ATS 2.58 unused function key
630 BEQ full \ display full screen
640 CMP #&19 \ 25 = shift+f9, ATS/ATS+ unused function key
650 BEQ down \ scroll down screen
660 .up
670 LDA lsb \ low byte of the top LH corner
680 CLD
690 SEC
700 SBC #&28 \ calculate new top LH corner of screen,
\ low byte
710 STA lsb
720 LDA msb \ high byte of the top LH corner
730 SBC #&00 \ calculate new top LH corner of screen,
\ high byte
740 STA msb
750 INC counter
760 BEQ up \ if on the bottom line subtract again
770 LDA counter
780 CMP #&0E \ are we on the top line?
790 BCC scroll \ scroll the picture
800 JSR screenaddr \ re-initialise screen
810 .scroll
820 JSR all \ and alter registers 12 and 13
830 LDX #&00 \ register 0, horizontal total
840 LDY #&7F \ value 127
850 JSR sheila \ VDU 23;0,127;0;0;0
860 LDX #&04 \ register 4, vertical total
870 LDY #&0E \ decimal 14
880 JSR sheila \ VDU 23;4,14;0;0;0
890 LDX #&06 \ register 6, vertical displayed
900 LDY #&0C \ decimal 12
910 JSR sheila \ VDU 23;6,12;0;0;0
920 INX \ register 7, vertical sync
930 INY \ Y = 13
940 .sheila
950 STX addreg \ select 6845 internal register
960 STY intreg \ store Y in 6845 internal register
970 RTS
980 .down
990 LDA lsb \ low byte of the top LH corner
1000 CLD
1010 CLC
1020 ADC #&28 \ calculate new top LH corner of screen,
\ low byte
1030 STA lsb
1040 LDA msb \ high byte of the top LH corner
1050 ADC #&00 \ calculate new top LH corner of screen,
\ high byte
1060 STA msb
1070 DEC counter
1080 BMI full \ restore full page
1090 BNE scroll \ scroll if not the last line
1100 LDA #&07
1110 JSR oswrch \ beep on the bottom line
1120 BNE scroll \ scroll for the last ime
1130 .full
1140 JSR screenaddr \ address of top LH corner of displayed
\ screen
1150 JSR all \ alter registers 12 and 13
1160 LDX #&00 \ register 0, horizontal total
1170 LDY #&3F \ decimal 63
1180 JSR sheila \ VDU 23;0,63;0;0;0
1190 LDX #&04 \ register 4, vertical total
1200 LDY #&1E \ decimal 30
1210 JSR sheila \ VDU 23;4,30;0;0;0
1220 LDX #&06 \ register 6, vertical displayed
1230 LDY #&19 \ decimal 25
1240 JSR sheila \ VDU 23;6,25;0;0;0
1250 INX \ register 7, vertical sync
1260 LDY #&1B \ decimal 27
1270 JMP sheila \ VDU 23;7,27;0;0;0 and return
1280 .all
1290 LDX #&0C \ register 12, high byte screen start address
1300 LDY msb \ value
1310 JSR sheila \ VDU 23;12,msb;0;0;0
1320 INX \ register 13, low byte screen start address
1330 LDY lsb \ value
1340 JSR sheila \ VDU 23;13,lsb;0;0;0
1350 LDA #&13 \ decimal 19
1360 JMP osbyte \ wait for vertical sync then return
1370 .counter
1380 EQUB &00
1390 .lsb
1400 EQUB &00
1410 .msb
1420 EQUB &00
1430 .oldvector
1440 EQUW &00
1450 .lastbyte
1460 ]
1470 NEXT
1480 INPUT"Filename for object code = "save$
1490 IF save$ ="" CALL mcode : END
1500 *OPT1,2
1510 OSCLI("SAVE "+save$+" "+STR$~(&FFFF0000 OR firstbyte)+" "
+STR$~(&FFFF0000 OR lastbyte))
1520 *OPT0,0
A program called SUBTITL is also broadcast with this module and it can be
used to give the ATS function keys the same capability as the ATS+ 1.00
function keys used with the Advanced Teletext Receiver. This program
enables the use of subtitles with Shift+f8. Chain the program and either
specify a filename for the object code or press the Return key to install
the routine. Subtitles can then be called on the currently selected
channel by pressing Shift+f8. To exit from the subtitle routine press f9
(without Shift) followed by Break.
00000000 49 6e 74 65 72 66 61 63 69 6e 67 20 77 69 74 68 |Interfacing with|
00000010 20 74 68 65 20 41 63 6f 72 6e 20 54 65 6c 65 74 | the Acorn Telet|
00000020 65 78 74 20 41 64 61 70 74 6f 72 20 2d 20 62 79 |ext Adaptor - by|
00000030 20 2d 20 47 6f 72 64 6f 6e 20 48 6f 72 73 69 6e | - Gordon Horsin|
00000040 67 74 6f 6e 0d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d |gton.-----------|
00000050 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d |----------------|
*
00000080 2d 2d 2d 2d 2d 2d 2d 2d 2d 0d 0d 4d 6f 64 75 6c |---------..Modul|
00000090 65 20 30 2e 20 49 6e 74 72 6f 64 75 63 74 69 6f |e 0. Introductio|
000000a0 6e 0d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d |n.--------------|
000000b0 2d 2d 2d 2d 2d 2d 2d 2d 0d 0d 54 68 69 73 20 6d |--------..This m|
000000c0 6f 64 75 6c 65 20 69 6e 74 72 6f 64 75 63 65 73 |odule introduces|
000000d0 20 61 20 62 6c 6f 63 6b 20 6f 66 20 65 69 67 68 | a block of eigh|
000000e0 74 20 6d 6f 64 75 6c 65 73 20 77 68 69 63 68 20 |t modules which |
000000f0 64 65 61 6c 20 77 69 74 68 20 74 68 65 20 41 63 |deal with the Ac|
00000100 6f 72 6e 0d 54 65 6c 65 74 65 78 74 20 41 64 61 |orn.Teletext Ada|
00000110 70 74 6f 72 2e 20 54 68 65 20 74 65 63 68 6e 69 |ptor. The techni|
00000120 71 75 65 73 20 64 65 73 63 72 69 62 65 64 20 69 |ques described i|
00000130 6e 20 74 68 69 73 20 6d 6f 64 75 6c 65 20 61 6c |n this module al|
00000140 73 6f 20 61 70 70 6c 79 20 74 6f 0d 6f 74 68 65 |so apply to.othe|
00000150 72 20 61 64 61 70 74 6f 72 73 20 77 68 69 63 68 |r adaptors which|
00000160 20 75 73 65 20 61 20 42 42 43 20 45 6e 74 65 72 | use a BBC Enter|
00000170 70 72 69 73 65 73 20 41 54 53 20 52 4f 4d 20 28 |prises ATS ROM (|
00000180 73 75 63 68 20 61 73 20 74 68 65 20 4d 6f 72 6c |such as the Morl|
00000190 65 79 0d 61 64 61 70 74 6f 72 29 20 61 6e 64 20 |ey.adaptor) and |
000001a0 74 6f 20 74 68 65 20 47 49 53 20 41 54 53 2b 20 |to the GIS ATS+ |
000001b0 52 4f 4d 2c 20 62 75 74 20 74 68 65 20 74 65 63 |ROM, but the tec|
000001c0 68 6e 69 71 75 65 73 20 64 65 73 63 72 69 62 65 |hniques describe|
000001d0 64 20 69 6e 20 6d 6f 64 75 6c 65 73 0d 31 20 74 |d in modules.1 t|
000001e0 6f 20 37 20 63 61 6e 20 6f 6e 6c 79 20 62 65 20 |o 7 can only be |
000001f0 75 73 65 64 20 77 69 74 68 20 74 68 65 20 41 63 |used with the Ac|
00000200 6f 72 6e 20 61 64 61 70 74 6f 72 2e 0d 0d 54 68 |orn adaptor...Th|
00000210 65 20 65 69 67 68 74 20 6d 6f 64 75 6c 65 73 20 |e eight modules |
00000220 61 72 65 20 69 6e 20 66 69 6c 65 73 20 6e 61 6d |are in files nam|
00000230 65 64 20 54 2f 54 54 58 30 30 20 74 6f 20 54 2f |ed T/TTX00 to T/|
00000240 54 54 58 30 37 2e 20 54 68 65 20 66 6f 6c 6c 6f |TTX07. The follo|
00000250 77 69 6e 67 0d 74 6f 70 69 63 73 20 77 69 6c 6c |wing.topics will|
00000260 20 62 65 20 63 6f 76 65 72 65 64 20 69 6e 20 74 | be covered in t|
00000270 68 65 73 65 20 6d 6f 64 75 6c 65 73 2e 0d 0d 0d |hese modules....|
00000280 4d 6f 64 75 6c 65 20 30 2e 20 54 68 69 73 20 6d |Module 0. This m|
00000290 6f 64 75 6c 65 2e 20 49 6e 74 72 6f 64 75 63 74 |odule. Introduct|
000002a0 69 6f 6e 20 61 6e 64 20 65 78 74 65 6e 64 69 6e |ion and extendin|
000002b0 67 20 74 68 65 20 41 54 53 2e 0d 20 20 20 20 20 |g the ATS.. |
000002c0 20 20 20 20 20 50 72 6f 67 72 61 6d 73 3a 20 53 | Programs: S|
000002d0 43 52 4f 4c 4c 20 53 55 42 54 49 54 4c 0d 0d 4d |CROLL SUBTITL..M|
000002e0 6f 64 75 6c 65 20 31 2e 20 54 65 6c 65 74 65 78 |odule 1. Teletex|
000002f0 74 20 67 65 6e 65 72 61 74 65 64 20 69 6e 74 65 |t generated inte|
00000300 72 72 75 70 74 73 2e 0d 20 20 20 20 20 20 20 20 |rrupts.. |
00000310 20 20 50 72 6f 67 72 61 6d 3a 20 43 4f 55 4e 54 | Program: COUNT|
00000320 45 52 0d 0d 4d 6f 64 75 6c 65 20 32 2e 20 54 68 |ER..Module 2. Th|
00000330 65 20 54 65 6c 65 74 65 78 74 20 68 65 61 64 65 |e Teletext heade|
00000340 72 20 70 61 63 6b 65 74 2e 0d 20 20 20 20 20 20 |r packet.. |
00000350 20 20 20 20 50 72 6f 67 72 61 6d 3a 20 48 45 41 | Program: HEA|
00000360 44 45 52 0d 0d 4d 6f 64 75 6c 65 20 33 2e 20 44 |DER..Module 3. D|
00000370 65 73 69 67 6e 69 6e 67 20 61 20 73 69 6d 70 6c |esigning a simpl|
00000380 65 20 54 65 6c 65 74 65 78 74 20 66 72 61 6d 65 |e Teletext frame|
00000390 20 67 72 61 62 62 65 72 2e 0d 20 20 20 20 20 20 | grabber.. |
000003a0 20 20 20 20 50 72 6f 67 72 61 6d 3a 20 47 52 41 | Program: GRA|
000003b0 42 42 45 52 0d 0d 4d 6f 64 75 6c 65 20 34 2e 20 |BBER..Module 4. |
000003c0 44 65 73 69 67 6e 69 6e 67 20 61 20 73 69 6d 70 |Designing a simp|
000003d0 6c 65 20 54 65 6c 65 74 65 78 74 20 6b 65 79 77 |le Teletext keyw|
000003e0 6f 72 64 20 73 65 61 72 63 68 20 75 74 69 6c 69 |ord search utili|
000003f0 74 79 2e 0d 20 20 20 20 20 20 20 20 20 20 50 72 |ty.. Pr|
00000400 6f 67 72 61 6d 73 3a 20 4b 45 59 57 4f 52 44 0d |ograms: KEYWORD.|
00000410 0d 4d 6f 64 75 6c 65 20 35 2e 20 49 6e 64 65 70 |.Module 5. Indep|
00000420 65 6e 64 61 6e 74 20 44 61 74 61 20 53 65 72 76 |endant Data Serv|
00000430 69 63 65 73 2c 20 43 68 61 6e 6e 65 6c 73 20 30 |ices, Channels 0|
00000440 20 74 6f 20 37 2c 20 50 61 72 74 20 31 2e 0d 20 | to 7, Part 1.. |
00000450 20 20 20 20 20 20 20 20 20 50 72 6f 67 72 61 6d | Program|
00000460 3a 20 54 53 44 50 30 0d 0d 4d 6f 64 75 6c 65 20 |: TSDP0..Module |
00000470 36 2e 20 49 6e 64 65 70 65 6e 64 61 6e 74 20 44 |6. Independant D|
00000480 61 74 61 20 53 65 72 76 69 63 65 73 2c 20 43 68 |ata Services, Ch|
00000490 61 6e 6e 65 6c 73 20 30 20 74 6f 20 37 2c 20 50 |annels 0 to 7, P|
000004a0 61 72 74 20 32 2e 0d 20 20 20 20 20 20 20 20 20 |art 2.. |
000004b0 20 50 72 6f 67 72 61 6d 3a 20 54 53 44 50 32 0d | Program: TSDP2.|
000004c0 0d 4d 6f 64 75 6c 65 20 37 2e 20 49 6e 64 65 70 |.Module 7. Indep|
000004d0 65 6e 64 61 6e 74 20 44 61 74 61 20 53 65 72 76 |endant Data Serv|
000004e0 69 63 65 73 2c 20 43 68 61 6e 6e 65 6c 73 20 38 |ices, Channels 8|
000004f0 20 74 6f 20 31 35 2e 0d 20 20 20 20 20 20 20 20 | to 15.. |
00000500 20 20 50 72 6f 67 72 61 6d 3a 20 44 41 54 43 41 | Program: DATCA|
00000510 53 54 0d 0d 0d 54 68 65 20 6c 61 74 65 72 20 6d |ST...The later m|
00000520 6f 64 75 6c 65 73 20 64 65 76 65 6c 6f 70 20 74 |odules develop t|
00000530 68 65 20 69 64 65 61 73 20 61 6e 64 20 74 65 63 |he ideas and tec|
00000540 68 6e 69 71 75 65 73 20 64 65 73 63 72 69 62 65 |hniques describe|
00000550 64 20 69 6e 20 74 68 65 0d 65 61 72 6c 69 65 72 |d in the.earlier|
00000560 20 6d 6f 64 75 6c 65 73 20 61 6e 64 20 66 6f 72 | modules and for|
00000570 20 74 68 69 73 20 72 65 61 73 6f 6e 20 74 68 65 | this reason the|
00000580 79 20 6e 65 65 64 20 74 6f 20 62 65 20 77 6f 72 |y need to be wor|
00000590 6b 65 64 20 74 68 72 6f 75 67 68 20 66 72 6f 6d |ked through from|
000005a0 0d 62 65 67 69 6e 6e 69 6e 67 20 74 6f 20 65 6e |.beginning to en|
000005b0 64 20 72 61 74 68 65 72 20 74 68 61 6e 20 75 73 |d rather than us|
000005c0 65 64 20 61 73 20 61 20 72 65 66 65 72 65 6e 63 |ed as a referenc|
000005d0 65 20 67 75 69 64 65 2e 20 42 65 66 6f 72 65 20 |e guide. Before |
000005e0 73 74 61 72 74 69 6e 67 0d 79 6f 75 20 73 68 6f |starting.you sho|
000005f0 75 6c 64 20 72 65 61 64 20 61 6e 64 20 75 6e 64 |uld read and und|
00000600 65 72 73 74 61 6e 64 20 65 69 74 68 65 72 20 74 |erstand either t|
00000610 68 65 20 41 54 53 20 55 73 65 72 20 47 75 69 64 |he ATS User Guid|
00000620 65 20 6f 72 20 74 68 65 20 54 46 53 20 55 73 65 |e or the TFS Use|
00000630 72 0d 47 75 69 64 65 2e 20 49 74 20 77 6f 75 6c |r.Guide. It woul|
00000640 64 20 62 65 20 68 65 6c 70 66 75 6c 20 69 66 20 |d be helpful if |
00000650 79 6f 75 20 68 61 76 65 20 77 6f 72 6b 65 64 20 |you have worked |
00000660 74 68 72 6f 75 67 68 20 74 68 65 20 41 54 53 20 |through the ATS |
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00000680 72 65 76 69 6f 75 73 6c 79 20 62 72 6f 61 64 63 |reviously broadc|
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05-03-89/T\TTX00.m1
05-03-89/T\TTX00.m2
05-03-89/T\TTX00.m4
05-03-89/T\TTX00.m5
.