FAQs - Amiga Flyer - Manual Toaster Calibration

Amiga Video Toaster / Flyer FAQs
  Amiga Flyer
    Calibration Topics
      Manual Toaster Calibration

Product: Video Toaster 3.1 3.5 4.1

Platforms: 2000 3000 3000T 4000 4000T

The following information is recommended for use only by qualified personnel. It is highly technical and improper use may cause the Video Toaster to malfunction. To implement this procedure: You must be intimately familiar with NTSC video timing and equipment calibration with the following test bench tools:

NTSC video test signal generator
Vectorscope
Waveform monitor
Calibrated NTSC video monitor

Introduction:

In the Toaster 4000 and Toaster System 3.0 software there is a method to manually adjust seven internal hardware values normally determined by the AutoHue procedure. Since AutoHue already performs this function, manual adjustment is not necessary for normal use of the Toaster. This adjustment is undocumented specifically because it is possible for a user to cause the Toaster to malfunction by changing these settings without the proper knowledge or test equipment. Because of this, NewTek Technical Support cannot support any end-users attempting this calibration.

Hardware Setup Screen:

In 3.x software, from the Switcher screen hold down the Right SHIFT, Right ALT, and F10 keys simultaneously (4.x software users: first unload the editor using the CTRL + LEFT ALT + F8 key combo, then use above listed key combination to load the HS screen). You should see a screen labeled HARDWARE SETUP (the screen will appear purple on A2000/A3000's and grey on A4000's).

The Switcher button at the top right returns you to the Switcher. There is a large window in the center of the screen where instructions appear. Next is a row of seven buttons that activate the different calibration functions. Below these is a slider with a numeric readout to the right of it. This slider controls the adjustments. Below the slider is a button labeled Auto Adjust. This button activates the Toaster's regular AutoHue function. This is the automatic method of determining the best values for these parameters.

To the right of this button is a T-Bar, which is used to adjust an on-screen horizontal wipe that shows the difference between the Toaster's digital output and the analog reference video.

The Save button will save the current settings so they will be used every time the Toaster is powered on.

The Recall button will bring back the last saved settings, effectively erasing any unsaved changes. Never save any settings without carefully determining for certain with your test equipment that they are correct.

Adjustments:

Each of these adjustments requires that external SMPTE color bars be connected to the Toaster's input one. Connect a waveform monitor, a vectorscope, and a high-quality calibrated video monitor to the Toaster's program out. Disconnect any other inputs and make sure that the Amiga's 23-pin RGB port is connected to either an RGB monitor or an RGB terminator.

Pedestal:

This controls the pedestal level of the Toaster's digital output. The purpose is to match the brightness of the Toaster's digitally sampled output with that of the analog video passing through the Toaster. As you adjust the slider, refer to your waveform monitor to make the superimposed analog and digital pedestal levels match. There is a horizontal wipe positioned by default across the black and white parts of the SMPTE color bars. Your video monitor may serve as an additional visual reference.

Gain:

This controls the gain level of the Toaster's digital output. The purpose is to match the contrast of the Toaster's digitally sampled output with that of the analog video passing through the Toaster. As you adjust the slider, refer to your waveform monitor to make the superimposed analog and digital gain levels match. There is a horizontal wipe positioned by default across the black and white parts of the SMPTE color bars. Your video monitor may serve as an additional visual reference.

Lock Phase:

This control works in conjunction with the Toaster's hardware phase lock to govern how the Toaster sync generator locks onto the incoming video. As you adjust the slider, refer to your vectorscope to make the superimposed phases match. Your video monitor may serve as an additional visual reference.

A/D Phase:

This controls the Toaster's digital sampling clock phase in relation to the internal sync generator. The purpose is to match the color phase of the Toaster's digitally sampled output with that of the analog video passing through the Toaster. As you adjust the slider, refer to your vectorscope to make the superimposed analog and digital phases match. Your video monitor may serve as an additional visual reference. Note that the Lock Phase adjustment must be performed prior to adjusting the A/D phase.

Red, Green and Blue:

These three selections work identically and control the hue of the Toaster's background matte generator. Each will bring up a reference color at the top of the screen. The purpose is to match the colors at top and bottom of the screen as closely as possible (ignore brightness and contrast). As described in the manual, the Toaster's internal matte color generator is designed to generate approximate colors. If precise SMPTE color values such as 7.5 IRE black or 100 IRE white are needed, use the RGB sliders in CG to render a solid backdrop page which may then be saved to disk for future use.

Conclusion:

Either the ESC key, or the Switcher button at the top right, can be used to return you to the Switcher. You can use the "Save" button to save your adjustments, or, when you exit, if you have not saved the new settings, a requester will pop up, and ask if you wish to save the current settings.

Only save these settings after verifying their accuracy with properly calibrated test equipment. These settings are stored in a file called 'HS' in the main Toaster directory, where they are used each time the Toaster is restarted. If the settings should become corrupt or another Toaster card is installed in the machine, use AutoHue or Auto Adjust to automatically determine the best values.

Once you have completed adjustments and returned to the Switcher, if you are using 4.x software, you can reload the Editor by hitting the F8 key.