COMMENT ⊗   VALID 00009 PAGES
C REC  PAGE   DESCRIPTION
C00001 00001
C00002 00002	% Bugs (sigh) in Computers \& Typesetting
C00005 00003	% volume A
C00008 00004	% volume B
C00017 00005	% volume C
C00031 00006	% Volume D
C00032 00007	% volume E
C00040 00008	\bye
C00041 00009	Now here are some that I will make soon!
C00044 ENDMK
C⊗;
% Bugs (sigh) in Computers \& Typesetting

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  Jan\or Feb\or Mar\or Apr\or May\or Jun\or
  Jul\or Aug\or Sep\or Oct\or Nov\or Dec\fi
  \ \number\year}

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\def\rhead{Bugs in {\tensl Computers \& Typesetting as of \today}}
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  \hrule width\hsize
  \line{\lower3.5pt\vbox to13pt{}Page #1\hfil(#2)}\hrule width\hsize
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  \line{\lower3.5pt\vbox to13pt{}Volume #1\hfil(#2)}\hrule width\hsize
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\newdimen\nsize \newdimen\msize \newdimen\ninept \ninept=9pt
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\noindent This is a list of all corrections made to {\sl Computers \&
Typesetting}, Volumes A--E\null, since 15 June 1987. Corrections made to
the softcover version of {\sl The \TeX book} are the same as corrections to
Volume~A\null. Corrections to the softcover version of {\sl The
\slMF\kern1ptbook\/} are the same as corrections to Volume~C\null.
Some of these corrections have already been made in reprintings
of the books.
% volume A
\bugonpage A326, line 12 (9/20/87)

\ninepoint\noindent
its natural width. The |\hbox| version also invokes |\everypar|.

\bugonpage A379, line 15 (10/12/87)

\ninepoint
|\def\deleterightmost#1{\edef#1{\expandafter\xyzzy#1\xyzzy}}|

\bugonpage A454, lines 23--29 (8/13/87)

\begingroup
\hyphenpenalty=-1000 \pretolerance=-1 \tolerance=1000
\doublehyphendemerits=-100000 \finalhyphendemerits=-100000
\ddanger If a suitable starting letter is found, let it be in font~$f$.
Hyphenation is abandoned unless the |\hyphenchar| of~$f$ is between
0 and~255, and unless a character of that number exists in the font.
If this test is passed, \TeX\ continues to scan forward
until coming to something that's not one of the following three
``admissible items'': (1)~a character in font~$f$ whose |\lccode|
is nonzero; (2)~a ligature formed entirely from characters of type~(1);
(3)~an implicit kern. The first inadmissible item terminates this part of
the process; the trial word consists of all the letters found in admissible
items. Notice that all of these letters are in font~$f$.

\endgroup % end the special hyphenation conventions

\bugonpage A462, left column, line 7 (10/9/87)

\eightpoint\indent\qquad 152, 178, $\underline{360}$.

\bugonpage A473, entry for `page builder' (8/13/87)

\eightpoint\indent\quad when exercised, 122, 280--283, 286--287.

\bugonpage A481, right column (7/3/87)

|\z@|, $\underline{347}$, 348.\par
|\z@skip|, $\underline{347}$, 348.
% volume B
\hsize=35pc
\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
\def\to{\mathrel{.\,.}} % double dot, used only in math mode

\bugonpage B2, line 32 (11/17/87)

\ninepoint\noindent\hskip10pt
{\bf define} $\\{banner}\equiv\hbox{\tt\char'23}$%
{\tt This\]is\]TeX,\]Version\]2.7\char'23}\quad
$\{\,$printed when \TeX\ starts$\,\}$

\bugonpage B52, line 5 (8/13/87)

\tenpoint\noindent
cannot be done, i.e., if $\\{hi\_mem\_min}=\\{lo\_mem\_max}+1$,
we have to quit.

\bugonpage B154, lines 25, 29, 34 respectively (9/20/87)

\ninepoint\noindent\hskip20pt
$\\{cvl\_backup},\\{radix\_backup},\\{co\_backup}$: \\{small\_number};\quad
 $\{\,$to save \\{cur\_val\_level}, etc.$\,\}$\par\noindent\hskip10pt
$\\{co\_backup}\gets\\{cur\_order}$;
 $\\{backup\_backup}\gets\\{link}(\\{backup\_head})$;\par\noindent\hskip10pt
$\\{cur\_order}\gets\\{co\_backup}$;
 $\\{link}(\\{backup\_head})\gets\\{backup\_backup}$;

\bugonpage B155, new entry for mini-index (9/20/87)

\eightpoint\indent
\\{cur\_order}: \\{glue\_ord}, \S447.

\bugonpage B229, lines 6--8 (11/17/87)

\tenpoint\noindent
than $2↑{27}$.
If $z<2↑{23}$, the individual multiplications $b\cdot z$,
$c\cdot z$, $d\cdot z$ cannot overflow; otherwise we will divide $z$ by 2,
4, 8, or 16, to obtain a multiplier less than $2↑{23}$, and we can
compensate for this later. If $z$ has thereby been replaced by
$z↑\prime=z/2↑e$, let $\beta=2↑{4-e}$; we shall compute

\bugonpage B229, lines 11--12 (11/17/87)

\tenpoint\noindent
if $a=0$, or the same quantity minus $\alpha=2↑{4+e}z↑\prime$ if $a=255$.
This calculation must be done exactly, in order to guarantee portability
of \TeX\ between computers.

\bugonpage B230, lines 2--5 (11/17/87)

\ninepoint
\noindent\hskip10pt{\bf begin} $\\{alpha}\gets16$;\par
\noindent\hskip10pt{\bf while} $z\ge\oct{40000000}$ {\bf do}\par
\noindent\hskip20pt{\bf begin} $z\gets z\ {\bf div}\ 2$; \
 $\\{alpha}\gets\\{alpha}+\\{alpha}$; \ {\bf end};\par
\noindent\hskip10pt$\\{beta}\gets256\ {\bf div}\ \\{alpha}$; \
 $\\{alpha}\gets\\{alpha}\ast z$;\par

\bugonpage B245, new entry for mini-index (8/7/87)

\eightpoint\indent
\\{cur\_s}: \\{integer}, \S616.

\bugonpage B254, line 29 (8/7/87)

\ninepoint\noindent
\\{cur\_s}:  \\{integer};\quad
$\{\,$current depth of output box nesting, initially $-1\,\}$

\bugonpage B254, line 31 (8/7/87)

\ninepoint\noindent
[Remove the statement `$\\{cur\_s}\gets-1$;' and put it on page B244 at the
end of line 31.]

\bugonpage B259, line 13 (11/9/87)

\ninepoint\noindent\hskip20pt
{\bf begin }$\\{rule\_wd}\gets\\{rule\_wd}+10$;\quad
$\{\,$compensate for floating-point rounding$\,\}$\par\noindent\hskip20pt
$\\{edge}\gets\\{cur\_h}+\\{rule\_wd}$; $\\{lx}\gets0$;
$\langle\,$Let \\{cur\_h} be the position of the first box, and set

\bugonpage B259, line 17 (11/9/87)

\ninepoint\noindent\hskip20pt
$\\{cur\_h}\gets\\{edge}-10$; {\bf goto} \\{next\_p};

\bugonpage B263, line 21 (11/9/87)

\ninepoint\noindent\hskip20pt
{\bf begin }$\\{rule\_ht}\gets\\{rule\_ht}+10$;\quad
$\{\,$compensate for floating-point rounding$\,\}$\par\noindent\hskip20pt
$\\{edge}\gets\\{cur\_v}+\\{rule\_ht}$; $\\{lx}\gets0$;
$\langle\,$Let \\{cur\_v} be the position of the first box, and set

\bugonpage B263, line 25 (11/9/87)

\ninepoint\noindent\hskip20pt
$\\{cur\_v}\gets\\{edge}-10$; {\bf goto} \\{next\_p};

\bugonpage B266, line 8 (8/7/87)

\ninepoint\noindent\hskip10pt
\\{dvi\_out}(\\{eop}); \\{incr}(\\{total\_pages}); $\\{cur\_s}\gets-1$;

\bugonpage B266, new code between lines 31 and 32 (8/7/87)

\ninepoint
\noindent\hskip10pt{\bf while} $\\{cur\_s}>-1$ {\bf do}\par
\noindent\hskip20pt{\bf begin if} $\\{cur\_s}>0$ {\bf then}
	\\{dvi\_out}(\\{pop})\par
\noindent\hskip20pt{\bf else begin} \\{dvi\_out}(\\{eop});
	\\{incr}(\\{total\_pages})\par
\noindent\hskip30pt{\bf end};\par
\noindent\hskip20pt\\{decr}(\\{cur\_s});\par
\noindent\hskip20pt{\bf end};\par

\bugonpage B338, second-last line (8/19/87)

\ninepoint\noindent\kern10pt
$q\gets\\{link}(\\{head})$; $s\gets\\{head}$;

\bugonpage B339, line 4 (8/19/87)

\ninepoint\noindent\kern20pt
$s\gets q$; $q\gets\\{link}(q)$;

\bugonpage B339, new code to insert after line 10 (8/19/87)

\ninepoint
\noindent\kern10pt{\bf if} $o\ne0$ {\bf then}\par
\noindent\kern20pt{\bf begin} $r\gets\\{link}(q)$; $\\{link}(q)\gets\\{null}$;
 $q\gets\\{hpack}(q,\\{natural})$;\par
\noindent\kern20pt$\\{shift\_amount}(q)\gets o$; $\\{link}(q)\gets r$;
 $\\{link}(s)\gets q$;\par
\noindent\kern20pt{\bf end};\par
\noindent[These new lines also imply changes to the index that aren't
 shown in this errata list.]

\bugonpage B547, right column (9/20/87)

\eightpoint
\leftline{\\{co\_backup}:\quad $\underline{366}$.}

\bugonpage B548, right column (9/20/87)

\eightpoint
\leftline{\\{cur\_order}:\quad 366, $\underline{447}$, 448, 454, 462.}

\bugonpage B548, right column (8/7/87)

\eightpoint
\leftline{\\{cur\_s}:\quad 593, $\underline{616}$, 619, 629, 640, 642.}

\bugonpage B559, right column (8/13/87)

[Delete the entry for \\{low\_mem\_max}.]

\bugonpage B565, left column (8/7/87)

\eightpoint
\leftline{\\{pop}:\quad 584--585, $\underline{586}$, 590, 601, 608, 642.}

% volume C
\hsize=29pc
\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers

\bugonpage C26, bottom line (7/18/87)

\tenpoint\noindent
What angle corresponds to the direction North-Northwest?

\bugonpage C107, line 13 (10/7/87)

{\bf pickup penrazor} xscaled \\{heavyline}
  rotated (angle$(z_{32}-z_{31})+90$);

\bugonpage C331, just below the illustration (7/18/87)

\ninepoint\noindent
Such a pattern is, of course, rather unlikely to occur in a |gf| file,
but |GFtoDVI| would\cutpar

% Volume D
\hsize=35pc
\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
\def\to{\mathrel{.\,.}} % double dot, used only in math mode

\bugonpage D545, left column (10/31/87)

\eightpoint
\leftline{{\bf zscaled} primitive:\quad $\underline{893}$.}
\leftline{Zabala Salelles, Ignacio Andres:\quad 812.}

% volume E
\hsize=29pc
\def\dashto{\mathrel{\hbox{-\kern-.05em}\mkern3.9mu\hbox{-\kern-.05em}}}

\bugonpage E32, second-last line (9/20/87)

\tenpoint\noindent
after which comes `\\{math\_axis}\0; {\bf generate} |mathsy|' (which we
won't bother to\cutpar

\bugonpage E353, lines 38--39 (8/12/87)

\ninepoint
\leftline{\kern10pt{\bf else}: {\bf fill} \\{diag\_end}$(6r,5r,1,1,5l,6l)
 \dashto.9[z_{5l},z_{6l}]$}
\line{\kern30pt$.\,.\,\{z_5-z_6\}\,.1[z_{5r},z_{6r}]\dashto\rm cycle$;\hfil
 \% middle stem}

\bugonpage E387, line 13 (8/12/87)

\ninepoint
\line{\kern10pt{\bf pickup} \\{tiny}.\\{nib}; \ \\{bulb}$(3,4,5)$;\hfil\% bulb}

\bugonpage E413, lines 37--38 (8/12/87)

\ninepoint
\leftline{\kern10pt{\bf else}: {\bf fill} \\{diag\_end}$(6r,5r,1,1,5l,6l)
 \dashto.9[z_{5l},z_{6l}]$}
\line{\kern30pt$.\,.\,\{z_5-z_6\}\,.1[z_{5r},z_{6r}]\dashto\rm cycle$;\hfil
 \% middle stem}

\bugonpage E459, line 24 (8/7/87)

\ninepoint\noindent[Delete the `$=$' sign between `\\{lft}' and `$x_5$'.]

\bugonpage E485, line 4 (8/7/87)

\ninepoint\noindent[Delete the `$=$' sign between `\\{lft}' and `$x_5$'.]

\bugonpage E550, new line after line 23 (8/15/87)

\ninepoint\noindent\kern10pt
{\bf forsuffixes} $\hbox{\$}=\\{notch\_cut},\\{cap\_notch\_cut}$:
 {\bf if} $\hbox{\$}<3$: $\hbox{\$}:=3$; {\bf fi endfor}
\smallskip\noindent
[To make room for this, combine lines 38 and 39 into a single line.]

\bye
Now here are some that I will make soon!