The Alpha Technology Super4
The Super4 was a popular speed-up board for the TRS‑80 Model 4. Introduced in 1984 by Alpha Technology, Inc. (not to be confused with Alpha Products), the Super4 was both inexpensive and easy to install. As the advertisements stated, it required “No trace cutting. No soldering. No wires to connect.”
The Super4 package contained everything necessary for the speed-up, including a faster Z80 chip. Installation consisted of unplugging the 4 MHz Z80 CPU from the Model 4 and plugging the Super4 into the now empty Z80 socket.
The Super4 was sold in two versions:
- a 5 MHz version for the original Model 4/4P which cost $44.95
- a 6 MHz version for all later versions of the Model 4 which cost $79.95.
(Why were there two versions of the Super4? It was because of a design change by Radio Shack. The original version of the Model 4 ran more slowly than its 4 MHz speed suggested (as slow as 3.37 MHz). This was corrected by later Model 4 revisions. But those changes in the Model 4 design made two versions of the Super4 necessary.)
Alpha Technology was better known for their Supermem memory expansion. Many people installed both the Super4 and the Supermem, creating what some called a “Super Model 4.”
The Super4 was slower than competitors such as the H.I. Tech, Inc. XLR8er (6.144 MHz, but effectively much faster) and the Seatronics Super Speed-Up (8 MHz). But it was much less expensive than either and was still much faster than the 4.77 MHz IBM PC XT sold at the time.