HP48GX

[Dave Britten]

The 48GX is probably my favorite scientific HP calculator overall (the 48SX is a very close second, and I think it outdoes the GX in a couple of very specific regards).

I'd recommend these starting supplies:

Manuals. Both the standard users' guide and advanced users reference. You can probably get printed copies cheaply enough, but there are good quality PDF versions available. The 48 has LOTS of commands available, and you're going to want a good reference ("What are the parameters for CHOOSE again?...")

Get accustomed to the fact that in the RPL system, basically everything is a pointer to an object. The stack? A bunch of pointers to objects in memory. This is what offers such flexibility and efficient memory usage, with pretty much every object/data type being a first-class citizen of the OS.

RAM cards are very nice to have, but can be quite pricey. Expect to spend almost $100 (USD) if you want a 128 KB card. 32 KB cards are more reasonable, but you'd still be hard pressed to find one under $40. Incidentally, 128 KB cards are the largest that can be merged with main memory in slot 1, giving you 256 KB total RAM to work with. The second slot can accept cards of up to a few megabytes, but you're limited to "port" memory, which is generally used for installing libraries/programs.

Also, NEVER use a memory card that isn't specifically designed and labeled for use in a 48. I've been told that there's a nearly-compatible format used with some Epson word processors or something, and they sort of work, but under certain low-battery conditions, the card can cause a short circuit and damage the 48. In summary, if it doesn't specifically say it's for an HP 48, don't put it in an HP 48. TDS stuff is generally fine, as they specialized in HP 48 hardware/software.

There are quite a few software ROM cards out there, many of them intended for rather specific disciplines (there's a lot of surveying software available). It's up to you if any of these would be useful. Otherwise, just dig around hpcalc.org and see what you think might be worth downloading and installing.

Get a serial cable. I believe it's the same cable that the 95LX uses, so that could open up your shopping options. Beware: the 49G and 100LX/200LX both have 10-pin serial connectors, but the pin-outs are very different. There are two small adapters from HP that allow either of those cables to be used with a 48 or 95LX, but it's very difficult to tell if you have the correct cable/adapter combination. Just get the appropriate 4-pin cable.

Learn how to do custom menus (via the CST variable) and user-defined keys. You can get some huge efficiency gains from these.