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-
- Testcard Generator (C) Barry Walker.
- ------------------------------------
-
- With all of today's (April 1999) technology the definitive means of showimg
- images to the masses is the trusty old Cathode Ray Tube (CRT). Whether it be
- colour or black and white the "tube" has still to be beaten in price to
- performance ratio. So I decided to write a program to utilise my old A500
- AMIGA as a test tool to set up colour monitors/telvisions in PAL format.
- As this is a freeware program NTSC and SECAM have not been covered.
- I may include these modes if there is enough of a response to this program.
-
- -----------------------------------------------------------------------------
-
- Safety Notice:-
- ---------------
-
- As with all devices containing a CRT an extremely high voltage appears at
- the final anode cap (the POPPY), anything from 5KV (small oscilloscope tubes)
- to 30+KV (colour display tubes), so be VERY careful when making any internal
- adjustments as a mistake could be harmful at best or FATAL at worst.
-
- So again be VERY VERY CAREFUL.
- ------------------------------
-
- -----------------------------------------------------------------------------
-
- General Information:-
- ---------------------
-
- The program fits onto a standard AMIGA bootable Workbench floppy disk.
- The disk MUST have a volume label named "TESTCARD". There are also some
- more testcards in the Testcard directory utilising the various standard
- AMIGA PAL video modes in the format <width>x<height>x<number of colours>,
- e.g. 320x256x32 which is obviously standard Lores 32 colour mode. To make
- the disk bootable consult your AMIGA manual on how install it.
-
- If you have a hard disk drive and have booted up the machine from the hard
- disk drive, place the floppy disk into drive DF0:.
- Open up a Shell/CLI window from a Shell/CLI icon and type in the
- following statement:-
-
- Copy all df0: to dhx:Testcard<RETURN>
-
- where "dhx" is the volume name of the partition you want to install to,
- and "<RETURN>" is the ENTER key.
-
- Add a line to the startup-sequence, (usually after any ramdisk assignments)
- as follows:-
-
- Assign TESTCARD: dhx:testcard<RETURN>
-
- where "dhx" and "<RETURN>" are the same as before.
-
- -----------------------------------------------------------------------------
-
- PC Information:-
- ----------------
-
- There is also a freeware PC version in the TESTCARD:PC directory.
- It is zipped up using PKZIP.EXE (not supplied), and is approximately 8KB
- in size. It unzips to 2 files, one is about 1KB the other is about 20KB.
- Both are COM files and must be run from DOS and NOT through WINDOWS at all.
- Any type of ANSI.SYS must be disabled from the CONFIG.SYS file (i.e. REM the
- statement out) and rebooted into a DOS command prompt.
-
- -----------------------------------------------------------------------------
-
- The Program Proper:-
- --------------------
-
- It is assumed that you have already dismantled the TV/Monitor to access the
- electronics inside. It is also assumed that you have a manual for the said
- unit under test or repair.
-
- Whether the program runs from the icon or from a floppy boot disk, the first
- screen will be a serious WARNING screen to remind you of the hazards
- involved when working with any CRT type of equipment. Press the ~SPACE BAR~
- to continue.
-
- The next screen is a Hires testcard of 640x256x16. This is so that you can
- adjust any of the external user controls that are available. These will
- probably be Brightness, Colour, Contrast, Width, Height, Horizontal shift and
- Vertical shift. When you have done all the preliminary adjustments press the
- any key to continue.
-
- You are now in the program proper.
-
- If you are a qualified TV/Monitor service engineer then you need not read
- any furhter, the program is self explanitory. If you are not then read on.
-
- From now on a single capital letter inside brackets means a highlighted
- letter (e.g. (P) is highlighted P). The mouse is NOT used inside the program.
-
- The Highlighted Commands:-
- --------------------------
-
- (W)hite raster.
- ---------------
- This command has 3 levels from dark grey to bright white and is used to
- check Extra High Tension (EHT) regulation and picture "ballooning". This
- is generally a design problem and is not adjustable or repairable.
-
- (P)urity.
- ---------
- This command also has 3 levels, Red, Green and Blue, and is used to check
- the uniformity of each primary colour raster. The adjustment is usually done
- with the purity magnets and/or the scanning yoke assembly. Degaussing may
- also be rquired using a degaussing coil.
-
- (S)tatic convergence.
- ---------------------
- This command allows a "white cross" generated to be "centred" on the screen
- and to adjust the the scanning yoke, convergence and shift magnets/controls
- to produce the best possible centred white cross.
-
- (D)ynamic convergence.
- ----------------------
- This command generates a "crosshatch" picture to set all the neccessary
- controls for best RGB convergence to produce white lines without coloured
- edges to them. It also helps in the setting up the "pincushion, barrel and
- trapezoid" error circuits. The adjustments are usually made with the
- relevant error circuit correction controls.
-
- (F)ocus dots.
- -------------
- This command generates lines of dots so that the focus circuits can be
- adjusted for optimum focus at the extreme corners of the picture, with the
- best possible focus at the centre.
-
- (B)eam limiter.
- ---------------
- This command generates bright white and black blocks to check line sync
- pulling and beam limiting. This is probably a design problem and will not
- be adjustable at all. It is usually more of a problem on TV systems or CVBS
- type monitors.
-
- (V)ertical sync and (H)orizontal sync.
- --------------------------------------
- These commands check the immunity for a device under test to reject a signal
- interfering with the sync circuits. This is probably a design problem and
- will not be adjustable. It may however be a decoupling fault. It is usually
- more of a problem on TV systems or CVBS type monitors.
-
- (I)nterference gratings.
- ------------------------
- This is a none standard test. The command generates a series of black and
- white vertical lines 1 pixel wide each to create an interference pattern
- on the screen. There are 2 levels the first is used for TV systems and the
- second is used for dedicated monitors. It is used to check the shadowmask
- geometry against the front screen phosphors and the gun assembly. It is
- purely a check and will never be curable if it is a problem.
- If you see a pattern like "||||||" then this is a very good CRT.
- If you see a pattern like "))||((" then this is a good CRT.
- If you see a pattern like "((||))" then this ia also a good CRT.
- If you see no pattern at all then you have the perfect CRT (impossible).
- If you see a random shaped set of patterns then the CRT is poor to average.
- You may need to vary the brightness to see this effect.
-
- (G)ratings for frequency response.
- ----------------------------------
- This is the standard frequency grating test and shows the bandwidth of the
- video circuits and tube coupling circuits. A TV system may not show the
- bottom band due to the fact that its frequency limit is approximately 5MHZ.
- The frequencies are approximately, 500KHZ, 1MHZ, 2MHZ, 4MHZ and 8MHZ.
-
- (C)olourbar.
- ------------
- This command generates the 8 colours of the colourbar check. It is used to
- check colour flaring on very bright and/or very high saturation images and
- is usually an indication of an aging CRT itself. It is generally a fault and
- can be curable, but it is probably cheaper to buy a brand new unit.
-
- (T)estcard.
- -----------
- And finally a repeat of the initial testcard again. It is a Hires screen of
- 640x256x16 and is used to reset any external user controls so that it looks
- correct on the TV/Monitor under test.
-
- (A)udio test screen.
- --------------------
- This command places you into a second screen for basic audio tests.
- Each time an audio test is required the TESTCARD screen will be displayed.
- On exiting the TESTCARD the sound will be turned off and you will be
- returned to the main screen for the video checks.
-
- The Stereo sound checks.
- (1) Sinewaves of 400Hz Left channel and 1000Hz Right channel.
- (2) The opposite of (1). Both are for general audio checks.
- (3) Both channels 1000Hz for speaker phase checks.
- (4) As (3) but at 400Hz.
-
- Mono sound checks.
- Connect the left and right channels together (for older AMIGAS only).
- These two checks are for the UHF mode only.
- (5) 1000Hz Sinewave for aligning the IF and demodulator in TV sets.
- (6) As (5) but at 400Hz.
-
- (V)ideo test screen.
- --------------------
- This command returns you back to the main screen without any audio.
-
- (Q)uit.
- -------
- This command will either quit the program into a CLI window or will prompt
- if you want to reboot the machine, reminding you to remove the floppy disk
- if it is in the floppy boot drive.
-
- -----------------------------------------------------------------------------
-
- Acknowledgements:-
- ------------------
-
- First of all many thanks to my wife Tricia who allows me to spend many hours
- on my computers. She is on the 320x512x32 testcard in the TestCard/OCS
- drawer.
-
- Also to David Benn and Herbert Breuer for the ACE/AIDE combination supplied
- on an AMIGA FORMAT floppy disk which made it easy to compile this program.
-
- And to anyone else who I may have neglected or forgotten.
-
- -----------------------------------------------------------------------------
-
- Lastly:-
- --------
-
- If I get a good response to this tool/utility and you would like other video
- modes and stereo sound tests to be included then contact me either by Mail
- or Email at the following:-
-
- Mr Barry Walker,
- 70 King George Road,
- Loughborough,
- Leicestershire,
- LE11 2PA.
-
- Email on either:-
-
- 106161.3245@compuserve.com
- or
- wisecracker@tesco.net
-
- BYE...
-
- -----------------------------------------------------------------------------
-
-