Datasets:
HDTenEightyP
/
CompuServe

Dataset card Data Studio Files
xet
Community
text
stringlengths
0
99.6k
First, type in and LOAD the following definition:
: NEW-PUNCT ( CHAR -- FLAG)
ASCII : OVER = SWAP
ASCII + ASCII 0 >R OVER < SWAP R> < AND OR ;
Then, once your NEW-PUNCT has been loaded, type the following:
' NEW-PUNCT IS PUNCT?
Type the above carefully, or you could cause problems (don't forget the ' ). Blazin' Forth will now accept numbers as described in this section. If you prefer this new version, you may save the system with the word SAVE-FORTH. If you want to change back to the oolder version, do the following:
' (PUNCT?) IS PUNCT?
*ln2
Number Formatting -- Double Length Unsigned.
Pages 167-168
All of the definitions in this section will work as described, but they would be so much more readable using ASCII . Here are some examples:
: .PH# <# # # # # ASCII - HOLD #S #> TYPE SPACE ;
: .DATE <# # # ASCII / HOLD # # ASCII / HOLD #S #> TYPE SPACE ;
: :00 # SEXTAL # DECIMAL ASCII : HOLD ;
*ln2
Page 171
The definition that Brodie gives for .$ won't work in 83-forth. SIGN works on the value on the top of the stack. A definition that will work in 83-Forth is:
: .$ SWAP OVER DABS
<# # # ASCII . HOLD #S ROT ( to bring signed number to top)
ASCII $ HOLD SIGN #> TYPE SPACE ;
You might also noticw that the positions of the $ and SIGN have been switched. I prefer my negative dollars to have their signs in front of the $ sign. That's the only reason for this change.
*ln2
Page 174
The warning to experimenters is not true in Blazin' Forth. You can include punctuated, double-precision numbers inside of colon definitions, and they will work just fine. (I have never understood this restriction.) Note that other systems may not allow this.
*ln2
Page 175
The definition for R% on this page is simply wrong. It should be, instead:
: R% 10 M*/ 5 M+ 10 M/ S>D ROT DROP ;
Which gives $148.15 as an answer.
*fp0
*cn1;Chapter 8*cn0
*ln2
Page 194
See the note above (page 174). You do not need to use 2CONSTANT to include double numbers in Blazin' Forth. You may wish to do so as a matter of style, but it is not forced on you.
*ln2
*cn1;Chapter 9*cn0
*ln2
Brodies example:
110 ' LIMIT !
won't work with the '83 tick. Use
110 ' LIMIT >BODY !
instead. By the way, LIMIT is an important system constant in Blazin' Forth, and I don't recommend that you try this example on it.
*ln2
Vectored Execution:
*ln2
Page 218
The behaviour of ' and ['] in '83 Forth is exactly that described here. Ignore the footnote on '79s tick. You might also wish to look at the documentation for DEFER IS , which are very handy words for handling Vectored Execution.
*ln2
The Structure of a Dictionary Entry.
*ln2
Page 220
The structure of a dictionary entry for Blazin' Forth than described here. (Note: The '83 standard regards this as a system dependency, and does not specify any particular form of dictionary structure. Other systems may, and probably do, differ.)
In Blazin' Forth, the structure is:
LINK FIELD
NAME FIELD
CODE POINTER FIELD
PARAMETER FIELD
There is also an optional field, called the VIEW or LOCATE field. This field is used by LOCATE, and is added or not at the option of the user. With the view field included, the structure looks like this:
VIEW FIELD
NAME FIELD
CODE POINTER FIELD
PARAMETER FIELD
Compiling without the VIEW FIELD results in more compact (but not faster running) definitions, but note that LOCATE will not operate on any definition without a VIEW FIELD. To prevent the view field from being compiled:
VIEW OFF
To re-enable the compilation of the VIEW FIELD:
2 VIEW !
*ln2