----------------------------------- -------------------------------------------- Free 42 is a software clone of the Hewlett-Packard 42 S calculator. If you know how to use an HP - 42 S, you know how to use Free 42. If you're new to the HP - 42 S and its clones , you may want to take a peek at the manual. You can find documentation athttps://thomasokken.com/free 42 / # docThe remainder of this README file covers some miscellaneous tidbits that I had no other decent place to put. -------------------------------------------------- ----------------------------- Binary vs. Decimal Starting with release 1.4, Free 42 can be built with binary or with decimal floating point. Building the binary versions works as always (just say "make"); to build the decimal versions, set the BCD_MATH environment variable, or use "make -e BCD_MATH=1". When switching between building the decimal and binary version (or vice versa), be sure to do "make clean", to avoid linking the wrong objects. When building the Windows version using Visual C , choose the Free 42 Binary or Free 42 Decimal projects; these projects are set up so that all output files are written to separate directories (ReleaseBinary, ReleaseDecimal, DebugBinary, DebugDecimal), so you can switch between these projects without having to worry about cleaning up object files. -------------------------------------------------- ----------------------------- Creating Free 42 build environment in FreeBSD Create VirtualBox VM (using VirtualBox 5.2. 22) Install FreeBSD - 12 .0-RELEASE-amd 64 - dvd1.iso then: pkg install gnome3 pkg install xorg pkg install virtualbox-ose-additions in / etc / fstab, added: proc / proc procfs rw 0 0 in /etc/rc.conf, added: vboxguest_enable="YES" vboxservice_enable="YES" dbus_enable="YES" hald_enable="YES" gdm_enable="YES" gnome_enable="YES" That brings up the desktop. Now, some more stuff: pkg install devel / pkgconf pkg install devel / gmake -------------------------------------------------- ----------------------------- About the character sets: ('bigchars' and 'smallchars' arrays in core_display.c) The top half of the 256 character codes are like the bottom half, with these exceptions: 0x 80: thin colon (':') (looks different than regular colon) , while 0x 00 is a calculator -style divide sign (superposition of ':' and '-') 0x 81: small 'Y'; 0x 01: multiply sign 0x8a: displays 'LF' character (small 'L' and small 'F', slightly offset, squeezed into one character cell); 0x0a: actual linefeed (move to next line of display). The bigchars array contains 130 characters, in 5x8 pixel cells, corresponding to codes 0 - 129. Char 10 is the 'LF' ligature. Note: the 'x:' and 'y:' legends for the standard X and Y register display are built from 0x 78 (lowercase x), 0x 81 (small 'Y'), and 0x 80 (thin ':'). Note: 0x 01 (multiply) is different than 0x 78 (lowercase x) (it is 1 pixel higher). -------------------------------------------------- ----------------------------- HP - 42 S bugs that I found: If you activate the CUSTOM menu in KEYASN mode, go to its third row, and then switch to LCLBL mode, you get a menu row with labels "L", "M", "N", "O", "@", "XEQ"; these keys activate the commands XEQ ST Z, XEQ ST Y, XEQ ST X, XEQ ST L, XEQ 117, XEQ 118. These commands do actually work, but entering the corresponding labels into a program is a bit tricky ... ->POL and ->REC with a real number in X reject a string in Y (good), accept a real number in Y (good), accept a complex number in Y but only use its real part (undocumented and not very useful), and accept real and complex matrices in Y with weird results. I'd say the complex and matrix cases are all bugs, resulting from a missing parameter type check. If MATA, MATB, or MATX is the indexed matrix, and SIMQ resizes it to a smaller size, IJ aren't set to (1, 1) as they usually are when the indexed matrix is resized (though DIM or SIZE). As a result, IJ can end up pointing outside the allocated elements, and RCLEL and STOEL can then produce wacky results. HP - 42 S bugs that others have found: When COMB or PERM are invoked with bad arguments (e.g. X>Y), "Invalid Data" is returned (good), but all subsequent invocations of those two functions also yield that message, even if the parameters are now correct (bad). This condition can be cleared up by performing an operation that affects LASTx (but not STO ST L). Apparently some rev. B models do not have this bug; I have read that the original problem was a hardware bug, for which rev. B introduced a software workaround; somewhere in the rev. B production run the hardware bug was fixed, but now the software workaround would * cause * the bug. The bug also exists in all rev. C models, apparently (it does in mine, and in Emu 42 when run with a rev. C ROM!). I'm curious as to why a couple of basic, straightforward instructions like COMB and PERM would be sensitive to a hardware bug (and * only * they, apparently), but who am I to question what I've heard others report? I'm not about to spend weeks poring over ROM disassemblies to make sure ... In LINSigma mode, summing a matrix is buggy. I have seen it sum only the first row, and report a bogus value back in X (8. 47216900137 e - 489), and also seen it say Insufficient Memory when that clearly wasn't true; I have heard a report from someone else about the machine even locking up to the point where it needs a hard reset. In some versions, LINSigma mode, Sigma and Sigma- do not update LASTx. I read about this in a manual addendum from HP; however, I cannot reproduce this, neither on my real HP - 42 S nor on Emu 42 (both rev. C ROM). I have also heard a report that FCSTX is buggy in PWRF mode; I have not been able to confirm this yet but there appears to be more I have to read about it. Probably depends on your ROM version; I tested with rev. C but it seemed fine. Not sure if this is a bug or not: When KEYX or KEYG are used to reprogram the UP and DOWN keys, it would be nice if the 'updown' annunciator in the display got turned on to tip the user off. I'm not sure if the manual mentions this behavior (TODO - check), but the Programming Examples and Techniques book does (page 34, bottom). I've seen a discussion about this on the hpmuseum.org forum, and all were agreed it would be a nice feature, but it doesn't actually seem to work. At least it doesn't on my HP - 42 S, and I haven't heard anyone claim that it does work on theirs, either. Note: Free 42 does turn on the 'updown' annunciator. Although my general rule is to mimic the HP - 42 S as closely as possible, I felt that this was a nice feature and that it's pretty unlikely to break anything. :-) -------------------------------------------------- ----------------------------- [MIN], [MAX], and [FIND]: undocumented HP - 42 S matrix functions [MIN] finds the lowest element of the current column, starting at the current row, of the indexed matrix, and returns the element to X and the row where it was found to Y; [MAX] is like [MIN] except it finds the highest element; if the minimum or maximum is not unique (it is found in more than one row), the highest matching row is returned. [MIN] and [MAX] require the indexed matrix to be a real matrix, and they do not allow string elements in the column being searched. [FIND] locates a specific value, searching the indexed matrix left to right and top to bottom. The function works as a conditional: when a program is running, the following instruction is executed if a match is found, and skipped if a match is not found; when executed interactively, the display shows "Yes" if a match is found and "No" if not. Also, if a match is found, I and J are set to point to it. The indexed matrix may be real or complex, and the search value may be real, complex, or string; real or string values are only found in real matrices, and complex values are only found in complex matrices; in other words, 5 is not considered equal to 5 0i - mathematically speaking this is wrong, but on the other hand it is consistent with the behavior of the X=Y? and X!=Y? functions. -------------------------------------------------- ----------------------------- Differences between the Free 42 printer emulation and the HP - 42 S / 82240 Free 42 prints programs differently in NORM or TRACE modes: in NORM mode , the listing is right-justified, and in TRACE mode, the listing is compact (multiple commands per line). The HP 42 S does not do this; Free 42 "inherited" this behavior from the HP - 82143 printer, which the author remembers fondly. :-) When the HP - 42 S has to print a line that is too long to fit on one physical printer line (ie, more than 24 characters), it takes no special action. Whether the printer prints the overflow left- or right-justified remains to be found out. I should check the 82240 specs to see how it behaves. Free 42 usually prints the overflow left-justified; the only exceptions are PRP and LIST in NORM mode.
GIPHY App Key not set. Please check settings