Pocket computer

Want to make a small computer/calculator that will fit in my pocket like this 80s one but using newer hardware instead, thinking of making it have a Forth system as it's OS, with a focus on power efficiency, for it to be capable of running on watch batteries or maybe a small recheargable one. My knowledge of electronics is very limited but I have plenty of free time, has someone here experience with somethinh alike?. Where could I obtain the resources?, what kind of display is recommended?, how to connect the display?, how to fit every component on such a small package? and more questions to ask. Also low-power diy computers general.

Many people have built "smart" watches. Maybe you can do something similar, but bigger. Some examples: http://blog.zakkemble.net/diy-digital-wristwatch/ http://www.hardcopyworld.com/ngine/aduino/index.php/archives/670 https://jared.geek.nz/oshw-oled-watch

>>3140 Check out pine64 single board computers. Cheap, good ARM based boards

>>3140 I have a similar (dead) thead in /tech/. https://www.lainchan.org/%CE%A9/res/16722.html I want to create a modern PDA, updated for the modern 2019 world. Particularly, I'm interested in using the Sharp memory LCDs, as well as using an ESP8266 (or something maybe fancier). I also want to incorporate an FPGA into it and write/run a Lisp OS on a Lisp CPU, but that's far, far, far down the line. Have you seen the DM42? It's a modern (2018) build of the original line of HP calculators, with a fancy new display, ARM microcontrollers and fully open-source: https://www.youtube.com/watch?v=D5D7CcLP4kM If I were you, I'd do the following: - finding a small PDA on ebay - maybe a Sharp Zaurus or similar, then opening it up and measuring the PCB. I like going this route because you get to design to a constrained space (instead of 3d printing your own case and trying to figure out how to make your own buttons if you don't wanna use tactile switches) - from there, figuring out what microcontroller (or microprocessor/FPGA + RAM if you're going that route). there's also nothing wrong with building a ton of prototypes with an Arduino and then using an ATMega328 on your PCB, it's real nice to be able to just flash your firmware and have everything just werk - for displays, if you want simple and inexpensive, you can get really cheap reasonable resolution displays on ebay or aliexpress ("3.5 inch TFT LCD Touch Screen Display Module 480X320" on eBay is $10 CAD). the displays are SPI-based, so just hook up the SPI lines from the display to your microcontroller's SPI pins -there's a bunch of Forth systems already existing on some other microcontroller platforms: Mecrisp (http://mecrisp.sourceforge.net/) is supported on both MSP430 and STM32 platforms, so you can buy a MSP430 Launchpad dev kit or STM32F103 dev kit for $10 each, prototype with it and connect it to the SPI display, write firmware in Forth, and then figure out PCB schematics/routing/layout later when you're ready - for making PCBs, you can use Eagle (free for boards smaller than 10x10 cm), KiCad (which I prefer because it's Free), or CircuitMaker (which is the free version of Altium, an industry-grade PCB design tool). Altium/Circuitmaker is very, very good and I use it at work.

>>3140 some guy here made this https://imgur.com/a/h2kR0Gs there was a reddit post somewhere as well

This is a little notebook ubuntu laptop/tablet. Not quite pocket sized, but (relatively) easy on the wallet to make. The overview of features https://n-o-d-e.net/ubuntu_laptop_overview.html The recipe https://n-o-d-e.net/ubuntu_laptop_how.html

I'd suggest buying a Texas Instruments calculator (I have a 84 Plus CE, but you may want to look into older ones based on your needs). I don't think there are any Forth OSes, but Cemetech actually does have alternate operating systems.