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LNW80 Microcomputer Restoration

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  LNW80 Microcomputer Restoration by Bill Degnan - 05/09/2019 10:06
LNW 80 Microcomputer
The LNW80 computer is a Radio Shack TRS 80 Model 1 clone, more or less. The BASIC is different and the memory map is different. Any programs that rely on either of these things will not operate properly, but DOS PLUS and NEW DOS for the Model I is easily adapted for the LNW80. The photo above displays the opening panel of the Modular Software Associates LNW BASIC Demo. LNW BASIC has commands that employ the LNW80's color display capabilities. Click image for larger view.


LNW 80
With the chassis cover removed, this image reveals a twin control board configuration. On top is the System Expansion board with the main Z80 motherboard underneath. The System Expansion is the hardware equivalent of the TRS 80 Expansion Interface board. Click image for larger view.



LNW 80 Exapansion Board
Riser screws and power connector removed, the System Expansion Board has been lifted to a 90 degree angle relative to the motherboard in order to access the components there. Click image for larger view.


LNW 80 System Expansion board
The LNW System Expansion is connected to the motherboard via a flat cable. The System Expansion adds parallel printer and floppy disk interface capability to the system. Click image for larger view.


LNW 80
LNW sold a disk density doubler card that was designed to be installed into the 1771 chip socket on the System Expansion board. The doubler is shown in 5 1/4" mode, note the toggle switch in the upper-right corner of this photo. Note same 1771 chip found on most density doublers of this era. Click image for larger view.


LNW 80
The system ROMS are written on 2716's and include a minimalist version of BASIC without a key bounce routine, making it unusable. Click image for larger view.


Restoration involved opening the system, cleaning out the dust and re-seating the socketed chips.

I built a RGB cable for hi-res color video but I do not yet have a suitable monitor. I tried a few likely candidates but the synch or refresh rate is not compatible with anything I currently have. More to come.

NEXT: In addition to the RGB, I plan to dump the ROMS, test the 8 in drive capability and the RS232 port.

In 2008 I created a introductory LNW80 Thread with links to additional photos and info.


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