tri-graphs

[Joe Horn]

(08-25-2015 05:16 PM)tigger Wrote:  Where can I find trigraphs?
What are trigraphs?

I am not too familiar to this page...

Short answer: Look up "translation codes" in your calculator's manual. It's all there.

Long answer: When sending programs to/from an HP 48, 49, and 50 in ASCII mode, they encode unusual characters (such as the angle symbol) as "trigraphs" which consist of a backslash character \ followed by two ordinary characters. The trigraph for the angle character is \<) because <) looks sorta kinda like the angle character. The trigraph for infinity is \oo. And so on.

This translation happens when the "TIO" (Translate I/O) mode is at its default. The extent of translation can be changed by adjusting the TIO setting in the IO settings on your calculator.

The complete TIO table can be found here: http://holyjoe.net/hp/tiotable.htm

Since most museum members are familiar with these trigraphs, you'll often see RPL characters and commands spelled with them in postings here. For example, you'll see RPL programs surrounded with \<< and \>>. When typing them into your calculator, mentally perform the "translation" from trigraph to the real character. Trigraphs are used because they are easier to type on ordinary computer keyboards.

By the way, despite the name, not all trigraphs are three characters long. The trigraph for a carriage return is "\010", and in general any character can be encoded as a backslash followed by its three-digit decimal code.