Changes

The main oscillator for the ASIC is 40MHz. A divide by 9 output at 4.444MHz is provided with a 5:4 mark/space ratio. It is possible to change the main crystal to 9 x 4.33619MHz 43619MHz = 39.90257 MHz, slowing the whole system by 0.25%. This may or may not upset the disk drives, but even if this is the case, a diskless unit could provide PAL subcarrier frequency locked to the master oscillator, thus improving the picture quality.