Loadstar 128 #19/q19.d81/t.p-list plus

Text File | 1990-01-01 | 7.1 KB | 147 lines

                             P - L I S T   P L U S

                               by John K. Lunde


      P-LIST PLUS for the C128 is a BASIC listing utility that 'uncrunches'
text, translates all those strange graphic characters into their real-world
meanings, summarizes multiple entries and prints the results on titled and
numbered pages.  You can make listings in "reading" mode that show what the
program will do, or in "entry" mode to show the exact keystrokes needed to
enter it.  Output can be to the printer or screen.

FENDER'S NOTE: Since I use Jon Mattson's CONTROL80 in all my programs, and
recommend it to everyone, I asked John Lunde to make sure P-LIST PLUS
handles the extra commands that CONTROL80 provides.  A day later, John sent
me an upgrade that takes care of the tokens CONTROL 80 uses.  My thanks to
both Jo(h)ns!


  HOW TO USE P-LIST PLUS
  ----------------------

     If your printer has a skip-over-the-perforation feature or margin width
controls, disable them; otherwise they'll conflict with P-LIST PLUS's own
routines that do the same things.

     When you run P-LIST PLUS you'll see a title page displayed for a few
seconds and then be instructed to insert the target disk.  That's the disk
that has the program or programs on it that you want to list.  P-LIST PLUS
should work on any type of drive numbered between 8 and 32.

     Insert it, press a key and a catalog of the disk's contents will
shortly appear.  If you discover you've loaded the wrong disk, enter a "d"
and try again.

     To select a file for P-LISTing, move the pointer with the CRSR keys to
the filename and press RETURN.  You can use all four CRSR keys to move the
pointer, or F7 and F5 to page forward or back if the directory is more than
64 titles long.  The catalog will change pages automatically if you move the
pointer above the first title or below the last.

     Even though the program is compiled, the directory read routine is not
real fast.  Be patient; even the longest directory will be read in less than
20 seconds.

      Selecting a filename takes you to the "formatter", where you can enter
the output device, case, mode, width, title and range of lines to be listed.
Default settings are already provided, so if you're happy with them all you
have to do is press CRSR DOWN or RETURN until you're on the "List" line.
Use RETURN on that line to start listing.

     To change any entry on the formatter, just type over it: if P-LIST
can't handle your input, you'll be told that it's an "invalid entry".  The
length of the title is limited to the width of the listing or the width of
the formatter line, whichever is shorter, and addresses for listing should
be entered in the usual way.

     On the "Title" and "List" lines only, CLR clears the line; it has no
effect on other lines.  On the "List" line you can enter the range of line
numbers you want listed (if you don't want to list the whole program).  Just
use the normal syntax (for example, 1200-1400 will list lines 1200 through
1400).

     You can go back to the catalog or read a new disk directory by entering
C or D on the formatter.  To quit, press Q.

     Once the listing's started, you can pause it at any time by pressing
any key.  To resume, press any key except F1; pressing F1 will take you back
to the formatter.

     If you're listing to the printer, you'll be asked if you want to feed
the form before you return to the formatter: P-LIST PLUS keeps track of the
number of lines it's printed and after 54 lines advances the paper to start
a new page.  If you don't feed the form after the last line of a listing's
been printed, this "line count" will be kept and the next listing will
continue the same page -- even if you change target programs or list
something to the screen between printings.

     If you decide not to feed the form and then change your mind once
you're back at the formatter, press F7.

     Although P-LISTed programs read in a straightforward way, there are a
few peculiarities you need to be aware of.

 * There are five instructions that the reading mode can't reduce to single
meanings since their effects depend on the output device the target program
uses.  Two print as [FLASH ON/SGL. WIDTH] and [LWR CASE/DBL WIDTH]; in both
cases, the screen effect is on the left and the printer effect is on the
right.

 * The other three instructions are for color values that aren't the same on
the 40 and 80 column screens. The 40 column color is on the left.

 * Where the CHR$ effect of a value is known, reading mode translates it:
for instance, A$=CHR$(144) becomes A$=[BLK].  There are two values that have
no CHR$ effect, though, and these are translated by the word BIN(ary), so
that T$=CHR$(0) would P-LIST as T$=[BIN 0].

 * Reading mode also handles lines starting with REM in a special way: It
removes the line number and the word REM before printing the text of the
remark, which makes for a more readable listing.  If a REM line is found
within six lines of the bottom of the page, the form will be fed before the
line is printed so that the remark and the following code will be printed on
the same page.

 * Also, REMs that are at the end of a line are moved out to the right
margin with a dashed line to make them more visible.

 * There are three things that can make P-LIST PLUS crash: first, some
protection schemes and some word processor programs create filenames
containing control characters.  When P-LIST PLUS tries to list these names
to the screen, they "print" as instructions that can make hash of the
catalog.  The only thing you can do about this is to transfer the programs
you want to list to another disk and work from that.

 * Second, target programs can contain a subtle structural error: although
such programs load and run normally, there are a few "glitch bytes" between
the end of one line and the beginning of the next.  P-LIST PLUS will list up
to or partway through the "bad" line and then lock up.  To fix this, LOAD
the target program, LIST the problem line to the screen, put the cursor on
it and press RETURN.  This will clear the garbage out; reSAVE the target
program and it should P-LIST normally.

 * Third, P-LIST PLUS only works on BASIC programs.  If you try to list an
ML program that has no BASIC lines, the program will probably lock up.  All
you can do is reset the computer and the drive.

     Take half an hour to play with P-LIST PLUS; after that, you'll have a
good idea of how to use it.  P-LIST PLUS is so user-friendly that there's no
point in describing all its features; just assume that whatever you want to
do is possible and try it.  The worst that can happen is that the input will
be ignored.

JKL

FENDER'S FINAL NOTE: Since we had room on this issue of LOADSTAR 128, we put
the BASIC source code to P-LIST PLUS on the disk in a file called
"pl-plus.bas".  John's code is very readable and commented.  Feel free to
study it or modify it.  The opening REM statements tell how to set the
memory parameters in Abacus' BASIC 128 COMPILER before re-compiling.  Choose
option 3 (Advanced Development), then E for Memory.  Then press 1 for Bank 0
Start and enter 7168.  Go back to the First Menu and choose option 1
(P-Code).

                        **** R - Run    RETURN - Menu ****