cloos@acsu.buffalo.edu (James H. Cloos) (03/16/91)
Hello all. I've been looking at the, for lack of a better (ie, HP's) word, algebraic-flags found before each named XLIB that is a program. (Algebraics, etc. do not have these flags.) I do have to make one disclaimer, though: everything below is conjecture on my part, based on perusal of libraries 2 and 700h in the 48's ROM, and of the output of usrlib. Therefore, use this at your own risk. But if you know that I'm wrong, tell me so so that we all can benefit! If we assume that the `D' in D9d20....b2130 is at address N, then addresses N-3 to N-1 hold the xlib`s number w/in its library, addresses N-6 to N-4 hold the library's number, and addresses N-9 to N-7 hold the `algebraic- flags.' What I would like is to know what each bit of these flags signifies and how to use it in my libraries. What I've been albe to discern is below, a minimal subset of what it could be. To indicate each of the flags, I'll use the convention (xxx) where x is a hex integer. Thus, (800), (400), (200), (100) are the bits in the nybble at address N-9. Flag (400) indicates if the word can be integrated. Flag (080) indicates if the word can be differentiated. Flag (040) indicates if hte word can be inverted (ie., solved by ROOT). *See below for a comment on these.* If flag (001) is set, it usually means that the word's symbolic syntax is not the standard prefix format. (Ie, 'SIN(X)' or 'MAX(A,B)' are standard prefix format, while 'X!' or 'A MOD B' are not.) Flag (004) works with (001) in a way I haven't figured out yet. If flag (008) is set, then the N-9 and N-8 nybbles are ignored. In this way RPN commands can save a byte each by not including the N-8 or N-9 nybbles. Using sad, I've documented these occurances in library 2: 000, 3A1, 8C5, 080, 8C0, 005, CC5, 105, CC0, 400, 4C5, 4C0, 001, 800, 7A5, 3A5, 121, A, E, 8. Obviously more needs to be discovered/leaked ;^) but I hope that this can be useful to anyone trying to implement libraries containing xlibs useable in algebraics. NB: wrt the integrate, differentiate and solve flags, obviously info must be kept somewhere to indicate that, eg. ACOS is the inverse of COS. Where that is kept and if external libraries can hook in to that/those table(s) I do not know. At least (000), (001) and (005) can be used for algebraics of hte form: 'FACT(X)', 'X!', 'X+Y' respectively. (Some of the commands that have (005) as their flags do not appear to me to be infix, and some with (001) do not appear to be postfix (eg, NOT and MOD, respectively). (NOT is "prefix_w/o_parentheses" and MOD is "infix_with_spaces.") BTW: I hope I'm not predicting vaporware, but don't be surprised if RPLC goes beta by the end of March. Happy 48'ing! -JimC -- James H. Cloos, Jr. Phone: +1 716 673-1250 cloos@ACSU.Buffalo.EDU Snail: PersonalZipCode: 14048-0772, USA cloos@ub.UUCP Quote: <>