The LNW80

Startup

The LNW80 is a clone of the TRS-80 model 1 made by LNW Research. So only the differences are described.

The Startup message is similar to the TRS-80, but may print LNW-80 level II or nothing at all. Tandy or Microsoft might have threated with a lawsuit. The original LNW80 ROMs have (too) minute differences (apart from the startup message) with the TRS-80 ones.

Apart from the speedup, the extra features of the LNW80 are only supported from special software like LNWbasic. The ROM, being compatible to the TRS-80, has no support for it.

Differences

Inverse video
OUT 254, 1 reverses the screen
High resolution graphics
OUT 254, 2 switches into Mode 1. This makes the high res memory visible but not accessible. With OUT 254, 9 it is visible and accessible. As this also switches the ROM, lowres video and keybord out of the memory map this is not usable from BASIC without special drivers like LNW Basic. Drivers available from DOS make 80x24 character screens possible. Mode 1 is 480x192 monochrome. Of this 384x192 maps on the TRS-80 screen pixels and 96x192 is placed on the left side of the TRS-80 screen information. Mode 0 is the TRS-80 screen.
Color modes
Two color modes are available and supported from LNW Basic (extended disk basic). Mode 2 uses high res graphics memory to colorize the mode 0 graphics. This results in 128x48 dots and 8 colors. Mode 3 uses low res character memory to colorize the high res pixels. This results in 384x192 pixels on 128x48 color fields. Per color field a foreground and background color is selected from the basic 8 colors. The extension region is not used in mode 3. The colors are white, green, yellow, red, magenta, blue, blue-green and black.
4 MHz speedup
A special key allowed a speedup to 4 MHz. For DOSses which didn't support this a fall back to 1.77 MHz is possible (internal switch).
Color support.
With an optional color ROM (decoding, not software) RGB video output and NTSC video is possible.
RS232
The serial port is incorporated into the system expansion, the LNW version of the Expansion Interface. The only difference here is that software baudrate selection is not supported.

Extension

Links:

F.J. Kraan, 2004-05-02