The TRS-80 Screen Printer

written by Matthew Reed

The TRS-80 Screen Printer (catalog number 26-1151) was the first printer Radio Shack sold for the TRS-80 Model I. It was introduced in March 1978 for $599.00. As the name suggested, the Screen Printer could print only one thing: the contents of the TRS-80 screen.

The Screen Printer was a very compact unit, not much larger than the four-inch wide “electrosensitive paper” that it printed on. It had a “PRINT command switch” on the front of the unit. When that switch was pressed, the entire contents of the TRS-80 screen (including graphics) were printed out on the aluminum-coated paper in around two seconds.

Unlike most other Radio Shack printers, the Screen Printer didn’t connect to the line printer port on the Radio Shack Expansion Interface. The Screen Printer connected directly to the bus card edge connector on the Model I or on the Expansion Interface (also known as the Screen Printer connector).¹

Because the Screen Printer didn’t need an Expansion Interface, it could work on any Model I, from a 4K cassette-only Level I to a 48K Level II with floppy drives. In fact, the Screen Printer was the only Radio Shack printer to work with a Level I TRS-80 Model I.²

The SCI Systems Rotary Printer

The Screen Printer was an OEM version of the Rotary Printer manufactured by SCI Systems, Inc. of Huntsville, Alabama.

The Rotary Printer was a patented design that could print very fast (for the time) at 2,200 characters per second. As SCI Systems put it, the Rotary Printer could “print Lincoln’s Gettysburg Address in 3/4 of a second and the entire Constitution in 12 seconds.”

The Screen Printer used four-inch wide “electrosensitive paper.” Although not identical to the aluminum-coated paper used by the TRS-80 Quick Printer, it was very similar. Many people disliked aluminized paper because the aluminum coating tended to wear off with handling. On the other hand, the paper photocopied well and it “will not fade and is not affected by heat or light.”

Additional rolls of aluminized paper for the Screen Printer (item number ACP-0001) could be purchased from Radio Shack National Parts for $14.95 for three rolls.

Problems

The Screen Printer accessed the Model I hardware at a low level, and this caused compatibility problems with later versions of the Radio Shack Expansion Interface. The solution was a special buffered cable (item number AW-2340) to connect the Screen Printer to the Model I. The new cable was available for free from Radio Shack National Parts, as long as the old Screen Printer cable was exchanged at a Radio Shack store.

The TRS-80 Screen Printer was advertised briefly in 1978 and 1979. It only worked on the Model I and was fairly expensive for a printer that could just print the contents of the screen³. This was especially true when compared to the less expensive Quick Printer, which was introduced slightly after the Screen Printer.

Radio Shack dropped the price of the Screen Printer to $399.00 in 1979 and $199.00 in 1980. It probably remained at that price until they sold out.

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1. The bus card-edge connector on the Expansion Interface was still called the Screen Printer connector long after Radio Shack stopped selling the Screen Printer. ↩︎

2. Level I BASIC for the Model I had no printer output commands, so the front panel switch approach of the Screen Printer was the only option for Level I users. A 1980 Radio Shack catalog released after the Screen Printer was discontinued stated unambiguously “The Level I TRS-80 cannot be used with a printer.” ↩︎

3. The $599.00 Screen Printer was the same price as the original Level I Model I in 1977. ↩︎