Reminds me of my electronics R&D days on flight sims in the 1980s where the fix for one particularly edge-case timing issue was to replace a 74S TTL part (withi

Reminds me of my electronics R&D days on flight sims in the 1980s where the fix for one particularly edge-case timing issue was to replace a 74S TTL part (within a sea of 74S logic) with a 74LS one and INSIST that only 74LS parts were used in that particular socket. Job done, no need for more probing!