FlashTalk was a late version of TOPS which ran the AppleTalk protocol at 2 speeds, normal 230 Kbps and triple speed. In order to maintain compatibility with non-Flash devices, the driver added a secret handshake to every normal packet.

(Normal speed) Hi, can you go fast?

Hi, yes I'm fast. (Switch to fast speed)

Hi, I have data for you.

OK.

data packet

Got it. (drop back to normal)

or

(Normal speed) Hi, can you go fast?

Huh?

(still normal speed) Hi, I have data for you.

etc.

For large data packets it did speed things up about 2X overall. For short packets, it actually slowed transfers due to the extra overhead, and the fast packets caused all slow devices on the network to reset their serial ports because of the "noise". It was mostly used in all-PC networks with Sun's FlashTalk cards, where it didn't disrupt normal LocalTalk traffic. It was also not 100% compatible with active hubs like Farrallon's, Nuvotech's, and PCon's. Sun lost interest in TOPS within a few months of buying the company, and the technology never caught on. Apple disliked it because it bogged down large networks with lots of short packets, it was expensive, it was NIH, and it didn't work very well with Apple's own LocalTalk wiring setup. It worked much better with phone wire.