Free42 eXtensions is an attempt to add HP-IL capabilities to Free42.
You may use virtual HP-IL devices such as ILPER from Jeff Garnier / Christoph Giesselink or pyilper from Joachim Siebold and even real ones with the PIL-Box from Jeff Garnier!
some HP-IL functions already provided:
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Printing: All HP-42S print functions are translated to HP-IL 82162A commands with some drawbacks with graphics support and PRLCD related to the printer model.
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Mass storage: CREATE (screate), DIR (sdir), NEWM (snewm), PURGE, READP, READR, RENAME, SEC, UNSEC,WRTP (swrtp), WRTR (swrtr), ZERO. Commands operates as their 82160A HP-IL Module counterparts (or enhanced SKWID Extended IL Rom when noticed) with some tweaks:
- Spanning through multiple mass storage is not supported.
- One-dimensionnal real matrices keep the HP-41C data type format.
- Two data types added for single HP-42S objects and for multiple objects.
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Interface control: 82160A HP-IL Module - AUTOIO, MANIO, SELECT 82183A Extended IO Module - AID, CLRDEV, CLRLOOP, ID, NLOOP, RCLSEL, STAT.
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82183A Extended IO Module data transfer functions: INAC, INACL, INAE, INAN, INXB, OUTAC, OUTACL, OUTAE, OUTAN, OUTXB, ANUMDEL, tweaked to allow complex numbers import.
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82184A Plotter Module: CLIPUU, CSIZE, CSIZEO, DGTIZE, DRAW, FRAME, GCLEAR, IDRAW, IMOVE, IPLOT, LABEL, LDIR, LIMIT, LOCATD, LOCATE, LORG, LTYPE, LTYPEO, LXAXIS, LYAXIS, MOVE, PCLBUF, PDIR, PEN, PENDN, PENUP, PINIT, PLOT, PLREGX, PRCL, RATIO, RPLOT, SCALE, SETGU, SETUU, TICLEN, UNCLIP, WHERE, XAXIS, XAXISO, YAXIS, YAXISO. All other functions are user code, see ./modules/NewPlot.raw.
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Bonus functions
- DSKSEL function to select the desired mass storage device.
- IFC to reset loop controler
- PRTSEL function to select the desired printer, -1 to disable HPIL printer.
- INACCL stop at specified character or CR/LF, usefull to deal with CSV files.
Free42 is a software clone of the Hewlett-Packard 42S calculator. If you know how to use an HP-42S, you know how to use Free42. If you're new to the HP-42S and its clones, you may want to take a peek at the manual. You can find documentation at https://thomasokken.com/free42/#doc
The 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, Free42 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 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 Free42Binary or Free42Decimal 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 Free42 build environment in FreeBSD
Create VirtualBox VM (using VirtualBox 5.2.22) Install FreeBSD-12.0-RELEASE-amd64-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: 0x80: thin colon (':') (looks different than regular colon), while 0x00 is a calculator-style divide sign (superposition of ':' and '-') 0x81: small 'Y'; 0x01: 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 0x78 (lowercase x), 0x81 (small 'Y'), and 0x80 (thin ':'). Note: 0x01 (multiply) is different than 0x78 (lowercase x) (it is 1 pixel higher).
HP-42S 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-42S 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 Emu42 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 LINΣ mode, summing a matrix is buggy. I have seen it sum only the first row, and report a bogus value back in X (8.47216900137e-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, in LINΣ mode, Σ+ and Σ- do not update LASTx. I read about this in a manual addendum from HP; however, I cannot reproduce this, neither on my real HP-42S nor on Emu42 (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 ▲ and ▼ keys, it would be nice if the user would be alerted to this by the ▼▲ annunciator in the display turning on. The manual does not mention this behavior, but older editions of the Programming Examples and Techniques book do (page 34, bottom). It doesn't work on the actual calculator, at least not on any that I've heard of. Free42 does turn on the ▼▲ annunciator. Although my general rule is to mimic the HP-42S 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-42S 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 Free42 printer emulation and the HP-42S/82240
Free42 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 HP42S does not do this; Free42 "inherited" this behavior from the HP-82143 printer, which the author remembers fondly. :-)
When the HP-42S has to print a line that is too long to fit on one physical printer line (i.e., 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. Free42 usually prints the overflow left-justified; the only exceptions are PRP and LIST in NORM mode.