HP-48SX with 128k RAM card - what should I put on it?

[Nigel (UK)]

I recently acquired an HP-48SX with 128k RAM card in excellent physical condition. Despite the low-contrast display and the slowness of the equation and program editors I have a soft spot for this machine, having bought one new in 1990 and used it intensively for several years. I never had a RAM card, though - too expensive!

My question is: what should I put on the RAM card now? In other words, what's your favourite software for this machine? Something free would be nice, but that isn't essential. I'm potentially interested in anything - utilities, things that speed up operations, even games. I've looked at hpcalc.org but advice from users here would be really helpful.

Thanks in advance for any ideas!

Nigel (UK)