> Thats good to know. I bought a TI 99/4a as well at VCF with no
> power supply. I thought the machine with the expansion chasis for
> sale was a TI 994 though, not a 4a?
> I hope to play Tunnels of Doom on the machine once I get it going.
The Expansion unit came in two versions, very subtle differences visually (power button vs. switch), probably a ROM or two different on the inside. I am not sure which version came first. Anyway, the Expansion Unit is technically a "99/4" Expansion unit, but that may just be a naming thing. I am not sure the date the expansion unit was released, if it came out at the same time or before the 99/4a. I am sure the answer is on the Internet someplace.