The testing phase has been using NOR flash memory. The fastest version is rated at 70ns, and although much better performance was observed, it will not support a dot clock above 25MHz. The final design will use the 55ns rated Atmel AT27C020. A similar performance boost was assumed and this suggests a clock of 32MHz might be possible with this faster memory.

The AT27C020 is a one-time programable (OTP) device and it was finally time to commit a device to the video timing code. The 32MHz version of the code was programmed and tested. Unfortunately, the OTP ROM did not support 32MHz, or at least, not on the breadboard. The highest frequency achieved (with the crystals on hand) was 27MHz.

This clock was just fast enough to meet the 50Hz limit on the CRT and display what the faster clock would show at 60Hz. The result below is the high-res text mode of 80x75. There is no horizontal blanking, so the random text actually wraps around to display about 87 columns of text. Click on the image and zoom in to see it in all its glory!

I believe this might be the highest density text ever produced by a TTL-only computer.