Can the IBM PCjr be upgraded to support the better features of the Tandy 1000?

Question

It is well known that the IBM PCjr was a commercial failure and that the Tandy 1000 series of computers not only matched the features of the PCjr (other than maybe the wireless keyboard), it also provided more features. Such as better graphics and a sound chip built in.

I don't know off the top of my head how much "better" the Tandy's graphics were over the PCjr, but I don't believe the PCjr had any audio except a speaker for beeps.

So, my question is, was it possible to upgrade the PCjr to the same level of graphics and sound as the Tandy 1000?

EDIT

I was wrong about the sound abilities of the PCjr. It did have audio built in. But I'm not sure how it compared to Tandy.

Answer 1

The PCjr supports three-voice audio; the Tandy 1000 copied that so running games in Tandy mode should work on a PCjr too. Some games might need a small program to switch to three-voice audio on first.

Both the PCjr and Tandy 1000 support 16-colour graphics in 320×200, but many games which run on Tandy machines don't work on the PCjr. There is a simple enough hardware modification to make a PCjr Tandy-compatible though; the Internet Archive still has the details.

Going beyond Tandy compatibility, there are quite a few useful upgrades for the PCjr, including in particular replacing the 8088 CPU with a NEC V20. Nerdly Pleasures has details.

Nerdly Pleasures also has a detailed article on the differences between the PCjr and Tandy 1000. Apart from the slight differences in graphics handling, the major difference is the memory handling: the PCjr was designed for 128 KiB, whereas the Tandy 1000 was designed for more. The PCjr can be expanded but it retains quirks in its memory layout...