Both these varieties came from the convention. They provide a good illustration of the differences between the two chips listed in TCR. Notice the difference in size of the red square that takes up most of the face of the chip. The one with the larger red square takes up more space and leaves a smaller pair of yellow edge-spots.

I was always confused by these and thought a post here might help other collectors. These machine-readable chips were part of a live experiment that Mikohn conducted at Ballys. They were used in one pit for several months and then discontinued. I played there and found the machinery and software very intrusive. The worst aspect was the light that came on to indicate your hand busted before the card was even exposed on the table... the shoe had an optical reader.