assumptions of computing in 1962 and earlier.</para>
<para>Some features of MAD are only superficially odd. The all-caps
-listings look strange to modern eyes; the IBM 709 on which it was
+listings look strange to modern eyes; the IBM 704 on which it was
implemented had a pre-ASCII, pre-EBCDIC six-bit character set with no
lower-case letters and lacks several punctuation marks that later
became standard. The limitation to six characters in variable names,
(treated as 0 or space). Tape and drum devices are not
supported.</para>
-<para>The 709 had 36-bit words; MAD floats are translated to C
+<para>The 704 had 36-bit words; MAD floats are translated to C
doubles, which on modern machines have 32 or 64 bits. Precision and
overflow of numeric results may therefore differ. The original MAD
limit of 6 characters on variable names, labels, and string constants
hand-drawn across them). The original also some contained hand-drawn
script characters:</para>
+<para role='notebox'>Redactor's comments in the body of the text are
+decorated like this.</para>
+
<informaltable>
<tgroup cols='2'>
<thead>
<para>EPSLON and COMPLX and the like are not typos. As pointed out
earlier, MAD variable names are limited to the 6 characters in a
-six-bit character set that would fit in the IBM 709's 36-bit
+six-bit character set that would fit in the IBM 704's 36-bit
word.</para>
<para>A few typos in the original have been fixed; if you're really
<para>Here we have substituted ".G." for ">", ".LE." for "≤",
".ABS. (X+Y)" for "|x + y|". (The reason for these simple
-substitutions is characters such as >, ≤ as input to the computer.
-Such details are fully presented <!-- beginpage -->
-in Chapter II of this manual.)</para>
+substitutions is the lack of characters such as >, ≤ as input to
+the computer. Such details are fully presented <!-- beginpage --> in
+Chapter II of this manual.)</para>
+
+<para role='notebox'>The IBM 704 on which MAD was implemented had a
+very primitive pre-ASCII character set. It did not even include
+lowercase letters, let alone fancy punctuation like < and >.
+ASCII still lacks ≤ and ≥, but writing these as <= and >=
+became universal in later ASCII-based languages.</para>
<para>The flow diagram for our previous example, then, may be
rewritten as follows: (In order to keep the notation familiar when
LARGEQ = 1. + MAX. (6,Q)/3.
</programlisting>
-<para>Note that the set (in this use of MAX.) hose largest element is
+<para>Note that the set (in this use of MAX.) whose largest element is
desired is called Q, and N has the value 6. No DIMENSION statement is
needed for A is the EXTERNAL FUNCTION definition program above, since
A is there only as a "dummy variable", anyway. When
</mediaobject>
<!-- beginpage -->
-<!--
-the listing in the original was defective, missing continuation
-punches everywhere but in INTERNAL FUNCTION F.
--->
+
+<!-- This listing in the original was defective,
+missing continuation punches everywhere but in INTERNAL FUNCTION
+F. -->
+
<programlisting>
&newton2;
</programlisting>
location to be used for temporary storage. Consecutive elements will
be used as required by the following statements.</para>
</listitem>
+<!-- beginpage -->
<listitem>
<para>SAVE DATA &scriptL;</para>
</listitem>
</orderedlist>
</sect2>
+<!-- beginpage -->
<sect2><title>Input-Output Statements</title>
<para>In this section the follwing definition the following
</varlistentry>
<varlistentry>
<term>WRITE BINARY TAPE &scriptN;, &scriptL;</term>
+<!-- beginpage -->
<listitem>
<para>Transmits &scriptL; to tape &scriptN; in binary form as one
record.</para>
subroutine which returns control to the system in which the translated
program is imbedded) is automatically entered. This action can be
changed by executing the statement EXECUTE SETEOF. (&scriptS;). The
-subroutine SETEOF. sets the read routines to transfer to the
+subroutine SETEOF. <!-- beginpage --> sets the read routines to transfer to the
executable statement labelled &scriptS; when an end-of-file is
encountered. If the statement EXECUTED SETEOF. (0) is executed the
read routines will be reset to enter SYSTEM. when an end-of-file is
<sect2 id='format_specs'><title>Format Specifications</title>
<!-- in the original this title, unlike other sect2s, was all-capsed -->
-<para>When information is read from (or punched in) a card into (or from) a
-computer, it is necessary to know how this information has been
-allocated among the available columns of the card. Similarly,
+<para>When information is read from (or punched in) a card into (or
+from) a computer, it is necessary to know how this information has
+been allocated among the available columns of the card. Similarly,
whenever information is to be printed by a printer (either on-line of
off-line), it is necessary to know how this information has been
allocated among the columns available on the printer. A description
whose values are to be printed or punched or whose values are to be
read. (Occasionally, the information is contined entirely in the
format specification, so the list may be empty.) A format
-specification is a string of alphabetic characters (as described
-below) terminated by an "*". This string is stored six characters per
-computer word in a vector with integer mode. This vector may be
-preset (see section 3.7), computed, or read in as data.</para>
+specification is a string of alphabetic characters (as <!-- beginpage
+--> described below) terminated by an "*". This string is stored six
+characters per computer word in a vector with integer mode. This
+vector may be preset (see section 3.7), computed, or read in as
+data.</para>
<sect3 id='carriage_control'><title>Carriage Control</title>
following table. In each case the carriage control character is
effective before the rest of the specification is carried out.</para>
+<!-- beginpage -->
+
<informaltable frame='none' colsep='0' rowsep='0' role='centered'>
<tgroup cols='2'>
<tbody>
<para>(For the purposes of input-output the Boolean values 0B, 1B are
considered as integers and will be punched in cards and appear in
-print as 0, 1.) The integer indicates the size of the field; i.e.,
+print as 0, 1.)
+<!-- beginpage -->
+The integer indicates the size of the field; i.e.,
the number of available columns to be used. For example, K3 indicates
a 3-column octal field, C23 indicates a 23-column character field,
andf S31 indicates a blank field of 31 columns.</para>
<para role='centered'>
+0.x<subscript>1</subscript>x<subscript>2</subscript>x<subscript>3</subscript>x<subscript>4</subscript>x<subscript>5</subscript>E±n<subscript>1</subscript> n<subscript>2</subscript>
</para>
+<!-- beginpage -->
<para>where n<subscript>1</subscript>n<subscript>2</subscript> is the
exponent. On <emphasis>input cards</emphasis> numbers in E fields
the computer and outside.</para>
</sect3>
+<!-- beginpage -->
<sect3 id='field_repetition'><title>Repetition of Basic Field Specifications</title>
<para>If several consecutive fields can be described by the same basic
number itself to be modified, but the exponent is correspondingly
modified so the true value of the number remains <emphasis> unchanged
</emphasis>. Thus the number 0.9321E-3 would print as 0.9321E-03
+<!-- beginpage -->
according to the specification E18.4*, but it would print as
93.2100E-05 according to the specification 2PE18.4*. Unlike an F
number, the <emphasis> value </emphasis> is the same in either
ignored throughout all format specifications except when they occur as
characters in a Hollerith string. Note also, that while every field
specification of types S, I, E, F, K, and C must be followed by
-commas, the comma may be omitted after a Hollerith string of the type
+commas, the comma may be omitted after a
+<!-- beginpage -->
+Hollerith string of the type
described here. The comma may be used, however, if desired.</para>
</sect3>
A(8).) During the transmission of information, the input or output
subroutine scans both the list and the specification simultaneously,
correlating corresponding entries, and associating a field size, a
-type of conversion, etc. to each variable. If a Hollerith string is
+type of conversion, etc. to each variable.
+<!-- beginpage -->
+If a Hollerith string is
encountered in the specification, it is immediately transmitted, and
it is not associated with any item on the "list."</para>
<para role='centered'>
3F10.3 /4(F10.3, 6HBETA = I2)*
</para>
+<!-- beginpage -->
<para>the first line printed (or read) would have three fixed point numbers,
subsequent lines would all be printed (or read) according to the
</sect3>
</sect2>
</sect1>
+<!-- beginpage -->
<sect1><title>Declarations (Non-executable statements)</title>
<para>All constants are automatically assigned modes by the translator
(see <xref linkend='constants'/>). Other automatic assignments of
modes are:</para>
+<!-- beginpage -->
<orderedlist numeration='loweralpha'>
<listitem><para>A name appearing in the statement label field is
<para>Although any number of dimension declarations may be used in a
program, as many variables as desired may be "declared" in any
dimension declaration. The declaration consists of the word
-DIMENSION, followed by the variables to be declared. Each variable is
+DIMENSION, followed by
+<!-- beginpage -->
+the variables to be declared. Each variable is
immediately followed by one or two arguments (separated by a comma)
enclosed in parentheses, as follows:</para>
region depending on the value of V(1) at the time a reference is made
ot a matrix element during execution of the program. Observe that
this ability to vary the location of the initial array element (i.e.,
+<!-- beginpage -->
the array element with unit indices) within the linear array allows
the effective use of negative subscripts - in spite of the fact that
the defined ranges of the subscripts are positive.</para>
in to help in finding trouble spots during the development of the
program (not as necessary here as in longer problems, but a good
idea!).</para>
+<!-- beginpage -->
<para><emphasis>Flow Diagram:</emphasis></para>
<imagedata fileref='fig7.png'/>
</imageobject>
</mediaobject>
+<!-- beginpage -->
<para><emphasis>The Program:</emphasis></para>
<programlisting>
&quadratic;
+<!-- beginpage -->
*DATA
4. -8. 4.
0 5. 10.
<para>The problem is to write a program to generate the entire "truth
table" for the given expression T.</para>
+<!-- beginpage -->
<para><emphasis>Flow Diagram:</emphasis></para>
<imagedata fileref='fig8.png'/>
</imageobject>
</mediaobject>
+<!-- beginpage -->
<para><emphasis>The Program:</emphasis></para>
instead of the BOOLEAN declaration.</para>
</sect2>
+<!-- beginpage -->
<sect2><title>Example 3</title>
<para><emphasis>Problem:</emphasis> To approximate
<imagedata fileref='fig9.png'/>
</imageobject>
</mediaobject>
+<!-- beginpage -->
<para><emphasis>The Program:</emphasis></para>
<para>If, for some reason, the integral of sin 3x - cos(rx + 1) were
needed if 0 ≤ x ≤ 3, and the integral of sin 3x - cos(rx)
otherwise, the program might then be as follows:</para>
+<!-- beginpage -->
<para><emphasis>The Program:</emphasis></para>
+<!-- beginpage after H = (B-A)/N -->
<programlisting>
&simpsmain;
</programlisting>
0 2. 10 10.
</programlisting>
-<para>An alternate way tio write the first eight lines of this
+<para>An alternate way to write the first eight lines of this
program, illustrating one use of the FUNCTION NAME mode, would
be:</para>
TRANSFER TO READ
FUNCTION NAME S
</programlisting>
+<!-- beginpage -->
</sect2>
</sect1>
projects / mad.git / commitdiff