I have been talking about the Apple Newton a lot lately. If you want to skip all of the soldering and just take a stroll down memory late, Pablo Marx has created a web-based Newton OS 1.0 browser-based emulator on the web called Leibniz.
Leibniz lets you relive a stock Newton OS 1.0 playing with the software that comes bundled in ROM. The mouse pointer acts as the stylus for touch screen input. If you mouse to handwriting is as bad as mine, you can bring up the on screen keyboard and use the mouse to peck out typewritten input.
If you are so inclined, you can also download a version of the Leibniz emulator for your modern Intel or Apple Silicon Macintosh. To legally use an emulator like Leibniz, you need to dump a copy of the ROM chip from a Newton you already own. As many iin the Newton community have found, dumping your Newton ROM can be a bit of a pain, so Pablo Marx links to several ready-to-go ROM images for you.