Radio Shack Lower Case Kit

Lower case kit from a 1980
Radio Shack catalog

The inability to display lower case characters was a well known deficiency of the TRS-80 Model I. There were a number of third-party modifications created to address that limitation, the most popular of which was the Electric Pencil lowercase modification. But the Radio Shack Lower Case Kit (catalog number 26-1104) was Radio Shack’s official solution for adding lower case to the Model I.

Introduced in early 1980 as a companion product to the Scripsit word processor, the price for the Radio Shack Lower Case Kit started out at $99.99 (plus installation) but was soon lowered to $59.95. Despite the use of the name “kit,” Radio Shack required installation by a Radio Shack technician.

The Radio Shack kit took a slightly different approach from the Electric Pencil modification. It included a new character generator that improved the look of several of the lower case characters. Lower case was enabled all the time, with no switch to enable and disable it. This created the potential for conflicts but there were only a handful of incompatible programs. These included two Radio Shack programs: Level II Cassette Payroll and Accounts Receivable. Radio Shack provided updated versions of those programs to customers free of charge.

Even though the Radio Shack kit allowed lower case characters to be displayed on screen, the Model I ROM provided no consistent way to type them using the keyboard. Some programs, such as Scripsit, contained their own keyboard driver, but using lower case in Level II BASIC required a separate lower case driver. The kit came with a lower case driver on tape that loaded into high memory and enhanced the ROM keyboard driver to support lower case. Pressing SHIFT+0 toggled the upper/lower case state (there was no shifted 0 character on the TRS-80 keyboard). This key combination to switch case became standard across several TRS-80 models. Eventually most Model I disk operating systems automatically installed their own lower case drivers and didn’t require a separate driver.

The TRS-80 Model III, introduced not much later in August 1980, offered lower case as a standard feature. It had a lower case keyboard driver in ROM that toggled lower case with SHIFT+0, just like the Model I kit. Radio Shack never redesigned the Model I to integrate lower case before new FCC rules led to it being discontinued on January 1, 1981.

Written by Matthew Reed | Filed Under Hardware · lower case