Tandy released the TRS-80 Model III on July 26, 1980. The improvements of the Model III over the Model I include: built-in lowercase, a better keyboard with repeating keys, an enhanced character set, a real-time clock, 1500-baud cassette interface, a faster (2.03 MHz) Z80 processor, and elimination of the cable spaghetti (due to its all-in-one enclosure). A Model III with two floppy drives requires the use of only one electrical outlet; a two-drive Model I requires five outlets. The Model III avoided the complicated power on/off sequence of the Model I. Shortly after the Model III's introduction, Model I production was discontinued as it did not comply with new FCC regulations as of January 1, 1981 regarding electromagnetic interference.
Tandy distinguished between the high-end Model II and Model III, describing the latter as "an administrative system, good for things like word processing, data management and VisiCalc operations" and suitable for small businesses. The lowest-priced version of the Model III was sold with 4KB of RAM and cassette storage. The computer's CPU board has three banks of sockets (8 sockets to a bank) which take type 4116 DRAMs, so memory configurations come in 16KB, 32KB, or 48KB RAM memory sizes. Computers with 32K or 48K RAM can be upgraded with floppy disk drive storage. There is space inside the computer cabinet for two full-height drives.
(Photo: RadioShack)