Not sure if this is useful data, but I have actually seen two Phase5 Z3 cards that are different in signifigant ways. Supposedly, both of these cards were "upgradeable". For example, Card-A has an Emulex scsi controller, while Card-B has a Q-Logic. One card has only three socketed ICs on the whole unit, the rest are surface mounted (including all 5 "GAL" chips). The other card has about 10 socketed ICs, including the "GALs"; the remainder are soldered.
From what I have read, this upgrade "kit" was something the end-user just bought from dealers and installed himself. Is this assumption not correct? The word "kit", to me, implies "user-installed". Anyway, if this is indeed the case, then can we also assume that the "kit" would NOT require the user to replace surface mounted ICs, and only socketed ones? I mean come on, this is a PCB board.. what else could this "Kit" possibly contain besides maybe jumpers?
Jumping back to my first point: looking again at the two boards (neither of which is precluded from being upgraded), I notice that out of all the ICs on the board, only 3 chips are socketed ON BOTH BOARDS. Can we safely assume that the mysterious "upgrade kit" must be a replacement for one or more of these three chips? FYI, the "GALs" are not among the three.
On one of the cards, these three chips are labeled:
1: "Microchip 27C256-12/L 9420 CHA"
2: "PALCE22V10H-15JC/4 310VT2K"
3: "Mach110-15JC 310PNP5"
