Tandy keyboards are a bit of an anomaly. One of my retro computers, a Tandy 1000 SX, is still in transit, but, in the meantime, I've been doing research on keyboard options, as Tandy decided to use start bits in their keyboard protocol rather than stop bits, and, thus far, I've been unable to find anyone who has built a converter between the two. The Northgate Omnikey is one option, and there's another non-Tandy option, but the name escapes my. I've also read comments about the Tandy 1000 keyboard being a hold over from the Tandy 2000, but I know the Tandy 2000 keyboard uses the same 5-pin DIN as IBM keyboards, but the Tandy 1000 keyboard uses an 8-pin DIN. It was unclear whether it was literally the same keyboard with a different cable, or it was just physically the same but with a different protocol. I finally tracked down the technical reference to both the Tandy 2000 and the Tandy 1000 and reviewed the keyboard sections, and discovered that they are, indeed, identical aside from the connector.
According to the technical reference manuals, both keyboards share the same scancodes and the same timings, and everything in the Tandy 1000 manual is also in the Tandy 2000 manual. The only difference I could find in that section of the manuals is that the Tandy 2000 manual includes the keyboard's schematic, while the 1000 manual does not.
Finally, another Tandy anomaly is the naming of these two computers. The Tandy 2000 is the older of the two, and the 1000 is an entire line of computers that came after. I expect that Tandy updated the keyboard to the 8-pin DIN solely to cut confusion, as an IBM keyboards of the era had the same connector but was completely incompatible.