What's your favorite, if any? Apple II, C64, ZX Spectrum, PC, Commodore Amiga, Atari ST, Sun Sparc, PowerPC, random Motorola 68, SGI?
I love all but since I have limited space in my home I am mostly interested in C64, Amiga and Atari.
Probably most interesting is my ISDN work. I have a ton of equipment from line analyzers, CO emulators, H.320 videophones, etc.
The plan, if I ever find it in me to get started again, is to build my own user land ISDN stack (erlang and C have been what I’ve used so far) that supports a range of BRI and PRI hardware with support for extension. I also want to play with making a few fun reference applications for it, like an H.320 to Discord video call bridge.
For some neat old computer I have that I haven’t gotten around to playing with are an HP A600+, an SGI Indy with an IndyCam, a very good condition HP-86B (wish I hadn’t sold my serial port cartridge) as well as an old HP X11 terminal that I’ve gotten to work with modern Linux once, but not since.
I’d love to get my hands on a PDP-11 mini or IBM 5100 with APL, but those don’t go for sale often and tend to be pretty expensive.
A few years ago I bought a LSI-11 and a PDP-11 CPU (because of the ROM) on ebay. As I lacked the motivation to build myself a Qbus I bought a VaxStation 3100 which worked for one month and failed afterward.
Yet another old computer in my house!
Tinkering recently: Amiga, C64, 386/486 PCs.