HPex is dead, long live Alum!

[Liam Hays]

Hello everybody,

A while ago, I announced a piece of software I had written called HPex. It was a GUI RPL calculator transfer tool.

Unfortunately, it also sucked. HPex was written in Python and wxPython, meaning it required hundreds of megabytes of shared libraries, ran only on Linux, and had limited file transfer capabilities. I decided to make something better.

Introducing Alum. Alum is a command-line transfer tool that supports bidirectional XModem and one-way Kermit transfers, runs on Windows and Linux, and is a standalone executable. It is designed to be useful, not fancy. I used it as a gateway to learn the Rust programming language (which is super cool, check it out!). Alum contains homegrown implementations of the Kermit and XModem protocols, so it requires no external dependencies, and it can determine the checksum of any HP 48 object and automatically detect USB serial ports.

Please, try out Alum on your own setup. If you find a problem or want a feature, open an issue on GitHub or here on the Forum. I have only tested Alum with an HP 48GX, and it's very possible that newer models have different behavior. Finally, I have documented the XModem Server protocol in detail, using both the Conn4x source code on hpcalc.org and Wireshark to monitor serial traffic.