HPi95LX: A Retro-Style, Linux-Capable Palmtop
Rune Kyndal demonstrated a fully Linux-capable palmtop on a three-decade-old computer from Hewlett-Packard.
In 1991, Hewlett-Packard launched its 95LX palmtop running NEC V20 at a clock speed of 5.37MHz and 512KRAM along with MS-DOS 3.22 operating system for $700. After almost three decades, Rune Kyndal has developed a Linux-capable retro HP95LX and replaced the CPU with a Raspberry Pi Zero W.
The device uses TP4056, which is a complete constant-current/constant-voltage linear charger for single-cell lithium-ion batteries. It even provides under voltage cut-off to protect from undercharging the battery.
At the heart of the machine lies a Raspberry Pi Zero W, running off a 5V power supply. It uses theMT3608 based boost converter module — a six-pin SOT23 current mode step-up converter intended for small, low power applications.
The 4.3" LCD screen has a resolution of 800x480 pixels with a display parallel interface attached to the Raspberry Pi GPIO as well as stereo speakers and mic through a USB port.
After wiring the 40-pin LCD connector to the Raspberry Pi GPIO header, these are combined with a SX1308-based boost converter module to step the battery voltage up to 23V for the LED backlight.
Moreover, it comes with a decent number of peripherals, including a Micro USB LiPO Charger, a full size 10/100 Ethernet (USB), USB 2.0 and RS232 level serial port (USB) on the left side of the device. The other side of the palmtop has an infrared data port cover, giving access to TF-CARD, a USB 2.0, and a HDMI.
Kyndal plans to get a dedicated LCD interface module, a capacitive touch screen and possibly a Raspberry Pi webcam. His passion project demonstrates how people are still interested in playing with a computer over three decades old.
You can find his complete project details here, plus many more photos of the final product.
