The PMC-80
from October 1980 issue of 80 Microcomputing
The PMC-80 was probably the most successful of the TRS-80 Model I clones sold in the United States. It was the creation of EACA International Limited, a Hong Kong manufacturing company. Their Model I-compatible computer was sold around the world by different distributors using different names. In Australia and New Zealand, it was the System 80. In Europe, it was the Video Genie. In the United States and Canada, it was the PMC-80, distributed by Personal Micro Computers.
Originally priced at $645 with a 30-day money back guarantee, the PMC-80 was supposedly available only through mail order, although their advertisements stated “Sold through computer stores”. It was nearly 100% compatible with Model I software, in part because the ROMs were nearly identical. Some of the differences between the PMC-80 and the Model I included:
- The PMC-80 keyboard lacked CLEAR and UP ARROW keys.
- The PMC-80 had a built-in cassette recorder.
- The PMC-80 could drive either a monitor or a television set.
- Double-wide video on the PMC-80 wasn’t controllable through software and worked differently than the Model I.
- The PMC-80 printer and serial ports were mapped differently than a Model I.
A Personal Micro Computers advertisement from January 1981 stressed Model I compatibility:
The PMC-80 is a “work-alike” computer to the popular TRS-80 Model I, Level II by Tandy, Radio Shack. The PMC-80 has 16K bytes of RAM and the complete Level II 12K BASIC ROM by Microsoft that makes it 100% software compatible with programs from Radio Shack and from the hundreds of other independent suppliers.
But an advertisement from March 1981 was less explicit about the TRS-80 connection:
When you buy PMC-80 you get hardware and software compatibility with the most popular microcomputer system in the world – that means thousands of disk and cassette based programs and all kinds of peripherals are instantly available!
from December issue of 80 Microcomputing
Personal Micro Computers later advertised the PMC-81:
The PMC-81 is a disk oriented computer that maintains software compatibility with the disk-based Level II TRS-80 Model I computer as well as its sister PMC-80.
The PMC-81 starts with 16K of memory, 14K of ROM, utilizes a Z-80 microprocessor and contains a complete standard keyboard, built-in amplifier and speaker for sound, cassette interface and video monitor interface. Like the PMC-80, the PMC-81 uses the same EXP-100 Expander to add 32K more memory and interfaces for mini floppy disks, printer, RS-232C and S-100 bus.
In 1981, Tandy sued Personal Micro Computers for copyright infringement. The lawsuit concerned the I/O routines in the PMC-80 ROM, which were largely copied from the Model I ROM. The BASIC portion of the ROM wasn’t an issue because EACA, like Tandy, licensed the BASIC from Microsoft.
Personal Micro Computers attempted to have the case dismissed, but was unsuccessful. The court ruling in Tandy’s favor was an important decision in early computer copyright law, helping to establish the concept that code in a ROM is protected by copyright.
This is a later model than the PMC-80 (notice the arrow keys)
Photograph courtesy Terry Stewart
After their court loss, Personal Micro Computers stopped selling both the PMC-80 and the PMC-81. They briefly sold the EPS-80, which appeared to be a PMC-80 with Electric Pencil word processing software in ROM. PMC Software, a company with the same address as Personal Micro Computers, continued to sell software for the TRS-80, PMC-80, and PMC-81 until 1983. Some dealers, such as Vespa Computer Outlet, still advertised their remaining PMC-80s for sale as late as 1985.
Sales of the System 80 and Video Genie were unaffected by the United States court decision and continued for several years. Many of the incompatibility problems, such as the missing arrow keys, were fixed by subsequent versions. The System 80 is an interesting subject on its own and the best source for information is Terry Stewart’s excellent Tribute to Dick Smith’s System 80.
Filed Under Computers · Personal Micro Computers
Please leave a comment!