!Paperterm
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agk's phlog
30 Apr 2021 @ 2225
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written on X61
while journeying
among the e-wastes
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I'm married! It was a perfect day. I promise to write
more soon.
My Pixel Qi 10.1" PQ3QI-01 LCD display panel arrived
today. It works in place of the smashed screen in the
ThinkPad X230 and the smashed screens in the Toshiba
NB205 and NB505 netbooks.
Pixel Qi displays were used in One Laptop Per Child
machines a decade ago. They are 1024x600, 60fps (much
faster than e-ink), transflective (readable in direct
sun with the backlight off), and promise to draw 0.5
watts with the backlight off or 2.5 watts with it on.
In the X230, the LVDS cable will have to be extended
and a means of affixing the display devised. The net-
books accomodate it easily but are in various stages
of disrepair. My dream of a cheap, low-power, rugged,
small, sunlight-readable laptop on which I can do
nursing coursework in the woods remains deferred.
I worked out a theoretical gut and retrofit of the
NB205 case with new innards. Here are specs of an
imaginary thing which I might try to build before the
baby is born:
* No fan, no touchpad, no camera, no mic, no speakers,
no headphone jack.
* 2-4 W of power consumption; 6-12 hours of active use
on battery; under 2 lbs; rugged; 8.5 in x 10.5 in.
* Keyboard + power button; 802.11 WLAN + bluetooth (BLE).
* Sunlight-readable display; indicator LEDs; terminal +
framebuffer + 3mux.
* CPU chipset agnostic; easily upgradable with cheap low-
power single-board computers/displays; extendable (with
a Lime SDR to serve as a cellular base station/PBX).
If I build the thing, I'll call it the Ship of Theseus.
The bill of materials includes:
* $10 Raspberry Pi Zero W (1GHz single-core ARM CPU,
512MB RAM, WLAN, BLE, 2x USB, 1x HDMI, 0.8W power
draw, 65 x 30 x 5mm dimensions).
* $25 Teensy++ 2.0 microcontroller (8 bit, 8-16 MHz
RISC, 2.7-5.5v OTG, 51 x 15 x 5mm) to interpret key-
strokes via Frank Adams' keyboard scanner board, and
control screen brightness and power on/off button
presses via $10 power control latch.
* $20 VGA controller board for LCD from NJYtouch (3.3v
barrel connector, requires MtM mHDMI to VGA cable).
* Two or three Buck voltage regulators ($15) and some
cables.
If I'm doing my math right, this would all cost under
$100, fit in the netbook case, and meet my specs.
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Notes:
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This sort of device has long been an interest of mine.
I'm currently inspired by modularity of MNT Reform
laptop, project definitions of PaperTerm and Steve
Lord's heirloom computing, and hacks of Frank Adams'
Pi Teensy Laptop.
