💾 Archived View for mirrors.apple2.org.za › archive › apple2.archive.umich.edu › apple2 › 8bit › pro… captured on 2024-12-17 at 23:11:17.
-=-=-=-=-=-=-
This is the intro file for QForth. I will be available at tm@polari.UUCP
for about one more week, then I'll have to find another account (I'm moving).
: newdefs
;
: title
page
1 cv 30 ch
." QForth 2.0 Alpha 1.0 "
3 cv 16 ch
." (c) 1988 Toshiyasu Morita, all rights reserved "
5 cv 18 ch
." (Type 'read intro' to execute this file) "
8 cv 18 ch
." 1) QForth overview "
9 cv 18 ch
." 2) QForth conditionals & loop statements "
10 cv 18 ch
." 3) QForth stack manipulation statements "
11 cv 18 ch
." 4) QForth miscellaneous statements "
12 cv 18 ch
." 5) Exit this menu "
15 cv 20 ch
." Please select help file to view: "
;
: overview
page
1 cv 32 ch
." QForth Overview "
3 cv 6 ch
." QForth is a fast, integer Forth designed for developing small "
4 cv 6 ch
." applications. QForth currently supports only unsigned integer "
5 cv 6 ch
." arithmetic, making it unsuitable for number-crunching applications. "
7 cv 6 ch
." QForth is, however, well-suited for developing small applications "
8 cv 6 ch
." that need to run quickly using little memory. QForth is perfect "
9 cv 6 ch
." for this task, since source compiles directly into machine language "
10 cv 6 ch
." and the kernel (presently) occupies a mere 6k. "
12 cv 6 ch
." This package does not include an editor as part of the language, so an "
13 cv 6 ch
." external full-screen editor is suggested. (Applewriter 2.1 is highly "
14 cv 6 ch
." recommended) "
16 cv 6 ch
." Since this is an alpha version, bugs and/or crashes are highly likely. "
17 cv 6 ch
." Please keep backups of your source files for safety! "
22 cv 32 ch
." Press any key: "
key drop 0
;
: conditionals
page
1 cv 22 ch
." QForth conditionals & loop operators "
3 cv 6 ch
." DO-LOOP: counts from top item in stack to 2nd item on stack. "
4 cv 6 ch
." loop variable is accessed through i and j. i will push "
5 cv 6 ch
." the innermost loop counter on the stack, and j will push "
6 cv 6 ch
." the next-to-innermost loop counter on the stack. "
8 cv 6 ch
." DO-+LOOP: Same as DO-LOOP except top item on stack is used at +LOOP "
9 cv 6 ch
." to increment the loop counter. "
11 cv 6 ch
." IF-ELSE-THEN: Basic Forth conditional. Top of stack is evaluated "
12 cv 6 ch
." at IF. If the value is true then execution continues "
13 cv 6 ch
." after IF to ELSE, then resumes execution at THEN. "
14 cv 6 ch
." If value is false then execution continues after ELSE "
15 cv 6 ch
." and on through THEN. "
17 cv 6 ch
." BEGIN-UNTIL: Executes statements between BEGIN and UNTIL, then top "
18 cv 6 ch
." of stack is evaluated at UNTIL. If value is true then "
19 cv 6 ch
." then execution exits loop, otherwise it loops to BEGIN. "
22 cv 32 ch
." Press any key: "
key drop
page
1 cv 22 ch
." Qforth conditionals & loop operators "
3 cv 6 ch
." BEGIN-REPEAT-WHILE: Execution proceeds from BEGIN to REPEAT, then "
4 cv 6 ch
." the the top of stack is tested at REPEAT. If top "
5 cv 6 ch
." of stack is true, then execution continues to "
6 cv 6 ch
." REPEAT and loops back to BEGIN otherwise the loop "
7 cv 6 ch
." terminates. "
22 cv 32 ch
." Press any key: "
key drop
;
: stack
page
1 cv 22 ch
." QForth stack manipulation statements "
3 cv 6 ch
." +, -, *, /, MOD: Performs specified operation on stack in "
4 cv 6 ch
." reverse-polish notation. "
6 cv 6 ch
." DUP: Duplicates top item on stack so that there are two copies. "
8 cv 6 ch
." DROP: Discards top item on stack. "
10 cv 6 ch
." SWAP: Reverses order of top two stack items, e.g. x, y becomes y, x. "
12 cv 6 ch
." OVER: Makes a copy of next-to-top stack item and pushes it on stack. "
14 cv 6 ch
." ROT: Rotates third item on stack to top, e.g. x, y, z becomes y, z, x. "
16 cv 6 ch
." >R: Moves top item on data stack to return stack. "
18 cv 6 ch
." R>: Moves top item on return stack to data stack. "
20 cv 6 ch
." R@: Copies top return stack item to data stack without removing it. "
22 cv 32 ch
." Press any key: "
key drop
page
1 cv 22 ch
." QForth stack manipulation statements "
3 cv 6 ch
." .: Prints out top item on stack followed by a space. "
5 cv 6 ch
." NOT, AND, OR, XOR, <, >, =: Performs specified operation on stack, "
6 cv 6 ch
." leaves result on stack. "
8 cv 6 ch
." 1+, 1-, 2+, 2-: Performs equivalent of 1 + or 1 -, etc. except words "
9 cv 6 ch
." are optimized for speed. "
11 cv 6 ch
." 2*, 2/: Arithmetic left shift and right shift, respectively. "
22 cv 32 ch
." Press any key: "
key drop
;
: other
page
1 cv 28 ch
." QForth other statements "
3 cv 6 ch
." !, @: Store and fetch two bytes from address to & from stack. "
5 cv 6 ch
." C!, C@: Store and fetch single bytes from address to & from stack. "
7 cv 6 ch
." PAGE: Clear screen and home cursor. "
9 cv 6 ch
." CV: Set cursor vertical position to top value on stack. "
11 cv 6 ch
." CH: Set cursor horizontal position to top value on stack. "
13 cv 6 ch
." KEY: Wait for a keypress, push ASCII value on stack. (high bit clear) "
15 cv 6 ch
." EMIT: Output to screen the ASCII value on stack. (high bit ignored) "
17 cv 6 ch
." CR, SPC: Output return and space to screen, respectively. "
19 cv 6 ch
." . " 34 emit ." : Output string to screen, must be terminated by another "
." quote. "
22 cv 32 ch
." Press any key: "
key drop
;
: main
title
begin
key 48 -
dup 1 =
if
overview
title
else
then
dup 2 =
if
conditionals
title
else
then
dup 3 =
if
stack
title
else
then
dup 4 =
if
other
title
else
then
5 =
until
forget newdefs
;
close main