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
- The LNW80 computer board fits with the LNW System Expansion to form one
printset, making it more reliable than the Model 1 / EI combination.
- LNW Research supplied an adapter which made CP/M possible. The software
80x24 video screen was also supported.
- The LNW80 model 2 has four graphic pages, with separate display and read/write
select lines.
Links:
F.J. Kraan, 2004-05-02