2640 (and maybe 2644, I can't remember) terminals have 8008s, 2641/2645/2648 terminals have 8080s (on different processor boards of course). An 8080 would likely be in a 40-pin DIP (Dual In-line Package, meaning two rows of pins). An 8008 would be in a smaller DIP but I can't remember how small off the top of my head.