Atmel ATF22V10 GALs have pin-keeper circuits that will cause I/Os
to be held either high or low (but not float) when disabled. This
feature consumes extra power, which causes problems with MTCR and
DOE on U306 because there are 4 other GAL inputs hanging off the
output. Thus, they don't securely go to 0V / 5V but get stuck
around 1-2V. Enable MTCR output to actively drive the signal. This
fixes half of the problem.
Alternatively R109E and R109H can be changed from 1kOhm to 560Ohm
to improve the signals.
Atmel ATF22V10 GALs have pin-keeper circuits that will cause I/Os to be held either high or low (but not float) when disabled. This feature consumes extra power, which causes problems with MTCR and DOE on U306 because there are 4 other GAL inputs hanging off the output. Thus, they don't securely go to 0V / 5V but get stuck around 1-2V. Enable MTCR output to actively drive the signal. This fixes half of the problem.
Alternatively R109E and R109H can be changed from 1kOhm to 560Ohm to improve the signals.
Found by dorken @ A1K.org