Main

Contents
TRS-80 Clones
LNW Computers
The PMC-80
The Lobo MAX-80
Other clones

TRS-80 Clones

TRS-80 Clones

Believe it or not, several companies actually cloned the wonderful TRS-80 line of computers, and made lots of useful add-ons for them (and regular Radio Shack machines, too). All this information is from other people, because I never owned a TRS-80 clone. I have included attributions, so you will know who to blame for mistakes. Mistakes in editing might be my own, though.

Top

LNW Computers

From Richard Gray (antiqueradio@earthlink.net), slightly edited:

Just for a little information, there was a TRS-80 clone called the LNW-80, a very powerfull machine, and it was color too. I have one with a hard drive, 3 disk drives, an epson dot matrix printer, and a 13" monochrome moniter, although it can support RGB moniters. The hard drive is a Corvus system hard drive, it might be 20megs but I'm not sure. When I get around to it I will send you more information.

From Glenn Diehl <gdiehl@startext.net>

I was reading your TRS80 info and I saw mention of the LNW80, and it brought back some memories. My father built one from the kit (really just the circuit board, instructions, and a bag of hard-to-find components) along with a clone of the expansion interface. It took months to find all the parts and put the thing together.

The machine had a Z80A (I think) processor that could run at double speed, enhanced graphics (420 (?) x192 b/w, 256x192 8-color, and a weird 384x192 8-color mode where the original Model 1 1K graphics buffer was used to overlay each character position with a color. The cassette drive worked at the hgher CPU speed, while disk accesses forced a temporary down-shift to the standard speed because of timimg issues.

Originally, my dad used the old TRS80 b/w monitor, but eventually completed the RGB circuitry and added an Amdek color monitor. It supported an RF modulator also, but I don't think he ever got that working.

Software wise, all the old stuff was compatible. LNW also marketed an enhanced Level III Basic that included commands for using the graphics capabilities (lines, circles, fills, etc.). They also had something called "Charm" that allowed you to design your own custom character sets. At last we could get 80x24 out of it.

From Al Hartman (compexpr@tribeca.ios.com), slightly chopped:

The LNW-80 computers were one of the early TRS-80 clones.

Originally, LNW Computers produced Expansion interfaces which you could buy in kit or assembled form. Their kits offered some advantages over the standard E/I.

The LNW Interface-80 supported CPUs which had been modified for high speed. They were more reliable because they used a redesigned memory circuit. The RS-232 Interface was on board (in fact, if memory serves, the LNW Interface 80 had TWO RS-232 Ports), so there were no heating/flexing problems like the ones with the Tandy E/I.

They shortly started to provide a motherboard kit. This kit allowed you to produce a complete TRS-80 compatible computer. This computer came with high-speed mod, lowercase mod, and composite video built-in.

This was the LNW-80 Model I. Eventually this was sold as a complete system in a metal case (aluminum I think..) which was painted white.

LNW also made a Double Density Adapter (the LNDoubler) which they included on later models. The LNDoubler had two features that the others didn't have. The first was that it would emulate the Tandy Doubler which used a different port address to access Double Density mode (MultiDos was one of the few DOS's that would directly support a Tandy Doubler without patching), AND it allowed you to attach an 8inch Floppy drive for 1.2mb of Storage.

The LNW also supported Color Graphics, RGB Output, and sound output.

The LNW-80 Model II supported CP/M, 80 column Video, had an Apple Compatible Joystick port and more. It came standard with an LNDoubler.

There was another TRS-80 Clone that came out near the end. It was called a "Trash Compactor". A company out in the mid-west built a replacement system board for a TRS-80 Model I which made it into a speedy Model III compatible. On One board this company combined the system board, E/I, Doubler, RS-232 adapter, etc.

It was priced around $399.00 or so. There were a couple models. The original model just incorporated the E/I into the Model I case, the second version replaced the Model I system board completely.

There was also a Color Graphics adapter for the TRS-80 model I/III from a company in Yaphank, NY. It was called the ELECTRIC CRAYON and used the same TI graphics chip that the Coleco Vision used. In fact, since the Coleco used a Z80 processor, these guys had plans to create a Coleco Emulator for the EC/TRS-8O Combo. They supplied an enhancement to Level II BASIC which included color commands and Turtle Graphics.

Another interesting device was the Merlin Adapter. This was an Adapter you attached to a Model III/IV and it allowed the Model III/IV to run MS-DOS software. I never heard much about it though.

Top

The PMC-80

From Leslie Ayling (layling@intercoast.com.au), slightly edited:

The PMC-80 (or SYSTEM 80 as it was known here in Australia) came in several models. From memory they were manufactured by a company called "Video Technology" based in Hong Kong.

Pre-release advertising suggested both 4kL1 and 16kL2 machines would be available. To the best of my knowledge only a few 4kL1 machines ever arrived in the country as samples, and were never sold to the public. At the time I worked for the Importer "Dick Smith Electronics" the same "Dick Smith" to first circumnavigate the globe by Helicopter.

1. The first System 80's arrived with 16kRam Lv2 Rom. They were packaged in an unshielded plastic case of cream and black with phony woodgrain along either side.

They had a cassette unit built into the main case with provision at the rear for connection of a second cassette unit.The inbuilt cassette had no volume adjustment and proved hopeless. A popular modification at the time switched the external deck to operate as the internal cassette unit.

The keyboard was standard Model 1 although [,],\,^ were used intead of the arrow keytops.

Internally there were 2 P.C. boards connected via a crude ribbon connector.

Lower case video hardware was built in via 2 2114 static rams although the character generator sported the []\^ chars instead of the arrows which was at times confusing.

32 char mode was not supported, instead you would just see double spaced ordinary characters due to the ROM routines remaining unchanged.

There was a built in RF Modulator for TV output as well as the 5 pin Din as on a Model 1 for connection to a monitor.

The rear panel sported an edge connector for connection to an expansion interface. However the connector had a different pinout to the Model 1 and was not compatible. It was gold plated though which saved it from the notorious random re-boot syndrome.

2. The Second Batch of System 80's arrived much the same except they now had a volume control and level meter attached to the inbuilt cassette deck.There was also a built in "Low-Pass" (?) filter which removed noise spikes between genuine clock and data pulses on the tape. It improved the cassette operation over a Model 1 markedly. Unfortunately it also made high speed cassette routines unusable!!. Owners continued to use the external cassette solution.

3. The "System 80 Business Computer" had a numeric keypad in place of the built-in cassette deck, and sold for $100 more surprisingly. (It didn't sell very well!).

There were 2 expansion options.

1. A simple printer interface plugged onto the edge connector at the back of the system unit giving a printer port at HF8 (i/o port ) The LPRINT rom routines supported the printer at this address however lots of Model 1 software looking for the printer at H37E0(?) failed to work properly on the System 80.

2. The full blown expansion interface (similar in size to the Model 1 equivalent) gave up to 48k ram total, a printer port (which could be modified to appear at H37E0) Serial port was built in ( it used a proper negative supply rail for the UART instead of the TRS80's charge pump arrangement, making it more reliable) and a 1771 disk interface. Also it had an external data seperator built on to the board, which worked great but had to be disabled with a simple modification if you wanted to use a PERCOM doubler or similar Double Density Interface.

And from from Lawrie Kemp (lkemp@ozemail.com.au) comes:

In Australia an electronics hobbyist company called Disk Smith Electronics (something like Tandy/Radio Shack) introduced a computer made in Hong Kong and based on the TRS-80 Model 1. It was called the Dick Smith System-80 and it contained an almost identical copy Level 2 Basic ROM and 16K RAM. The unit was very big compared to the TRS-80 and contained the power supply, an RF modulator and a cassette player in the main keyboard unit.

Like the TRS-80, the System-80 had an expansion unit with RS-232, Floppy Disk and extra 32K ram capabilities. The expansion bus was a 50pin connector and therefore not compatible with the TRS-80's 40pin bus.

The System-80 was later introduced in a "Business Edition" model with a numeric keypad fitted where the cassette player used to be and an additional ROM with a couple of minor functions I can't remember anymore.

I believe the System-80 was also available in the US under the name PMC-80 and in South Africa as the TRZ-80. The machine was eventually discontinued apparently due to copyright infringement of Tandy's ROM.

My first computer was a System-80 bought in 1980, see photo.

Feel free to add this info to your TRS-80 page. It's good to see the TRS-80 is still remembered by others too.

Top

Lobo MAX-80

From Tom Almy (tom.almy@tek.com)

I was the owner of a TRS-80 Model 1 and II, and *two* Lobo MAX-80's. The MAX-80 was both a TRS-80 Model III (basically) clone and a CP/M machine.

Features:

128K RAM. When running LDOS, there was a driver allowing use of the additional memory as a RAM Drive. CP/M Plus (CP/M-80 Version 3) used the memory as a disk cache and to hold CP/M allowing larger programs to run.

5 MHz Z80 processor

Interfaces for up to 4 5.25" and 4 8" floppy drives of any size. The 8" driver would also work with the then rare 3.5" floppies. SCSI interface for hard drives, which were about $2000 for a 10 meg drive.

Display ran 64/32x16 for TRS-80 apps or 80x25 for CP/M apps. There was software available to run 80x25 in LDOS as well for apps that would suport it. Fonts were held in ram, and thus were "programmable".

Two RS232 serial ports and a Centronix parallel port.

Clock/calendar w. battery backup.

The Z-80 system busses were brought out on an expansion connector, not compatible with TRS-80s. However I used this to add a 128K RAM Drive that was designed for "Big Board" CP/M systems, and wrote drivers for it both in LDOS and in CP/M.

The memory map in LDOS mode matched the TRS/80, however the serial/parallel ports and disk interface were not compatible at the hardware level. The MAX-80 did not offer a casette port, so games with sound were not possible (there was a Sonalert for the "bell"), and there was no way to slow down the clock. The machine was a dud at the local TRS-80 users group meeting because it was no good for games! I ran business apps on it, which all ran very well. In fact, I felt my machine was better than the original IBM-PC or XT, and didn't drop the Lobo until the PC-AT came along.

Top

Other Clones

From Egbert Schroeer (eschroer@huels.de)

The Trommelschlaeger Corporation (TCS) build a TRS80 clone in 1982 called GENIE I in Germany with SIEMENS. This computer was followed by GENIE II, GENIE III and the very special GENIE IIIs (with Phoenix BIOS) with high resolution graphic and harddisk. The next (and last generation) was the GENIE 16 and GENIE 16 B. All GENIE computers run with NewDos80 and the German version GDOS 2.x (latest version was 2.4, including hard disk capabilities). GENIE III series run also CP/M 2.2 - 3.0. The last GENIE was build (I'm not sure) in 1989.

From Eric Dittman (dittman@mailhost.dseg.ti.com)

Pete, I have a TRS-80 Model I clone - the Cyzern System 7000 - that not too many people seem to know about, although the clones were advertised in 80 Micro. This clone was available either preassembled or as a kit, and contained either 16K or 64K (48K available) and a custom version of the TRS-80 Level II BASIC. The heavy metal case contained four circuit boards: The keyboard/power/RF modulator/cassette board, the CPU board, the video board, and the memory board. The documentation listed upgrades for the CPU board (faster processor) and the video board (color), but I don't know if these were ever offered for sale. There was supposed to be other expansion boards that went inside the case (a floppy controller and a printer interface, maybe others), but I never bought them, but from the documentation they were more compatible with the Model III than the Model I.

Top



Top

The TRS-80 Home Page created and maintained by Pete Cervasio
cervasio@airmail.net

Copyright © 1998 Pete Cervasio