Joltima looks like so much fun! I hope you enjoy playing with the Series 3 as much as I do.
You should definitely check out TI-calculator gaming and programming if you don't know it already. There are dozens and dozens of great games and applications for these devices, especially for the TI-84 Plus (the classic monochrome one, not the later rebrandings TI-84 Plus CSE and CE) and TI-89 Titanium, ticalc.org's archives are choke-full of great stuff: https://www.ticalc.org/archives/files/.
I'm sure I'll have great fun with the Series 3 - I look forward to dive in this new ocean of possibilities. Thank you again for your help.
I've looked into it before and I'm very tempted by the TI-92 models, but having got back into the Psion S3 recently I probably wouldn't have time to give it the attention it deserves. I'm not even sure when I'll fit in a port of Dragonfell to the 3a/c/mx and the 32-bit Psion machines, especially since I'm still heavily into DOS development too.
I'm using Linux, but one of my solution should work for you. First, get yourself a serial terminal emulator (I don't know what the current ones are for 64-bit Windows). Set the comms parameters to 9600 bps, 8bit, no parity. You can then talk to the Psion via the Psion Comms application (remote link switched OFF on the Psion). Psion Comms supports Y-modem protocol, so while you need to transfer the files directly into the right folders on the Psion, you can do it a directory at a time.
The second option involves setting up DOSBox if you haven't already. Get it talking to your serial port, preferably as COM1 within DOSBox. Get a copy of the MCLINK software for DOS. Connect the Psion to the PC with remote link ON, and load MCLINK within DOSBox. You should then be able to transfer files to and fro using the commands in MCLINK (it has a TXT file) or using the Psion user interface.
There's a helpful and friendly Psion Discord if you get stuck, you can find the link on the Psion community web site https://psion.community/