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add links, improve things a bit more

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~d6 2024-08-03 01:03:42 -04:00
parent 2d0db6fe6f
commit 28f27e7fcf
1 changed files with 25 additions and 8 deletions
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uxntal.1
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@ -49,7 +49,7 @@ Unlike other opcodes, \fB0x00\fP is contextual. Its meaning depends on the \fImo
0x40 \fBJMI\fP 0xc0 \fBLITr\fP 0x40 \fBJMI\fP 0xc0 \fBLITr\fP
0x60 \fBJSI\fP 0xe0 \fBLIT2r\fP 0x60 \fBJSI\fP 0xe0 \fBLIT2r\fP
.SH REGULAR INSTRUCTIONS .SH STACK EFFECTS
Regular instructions have a single stack effect which is modified in a predictable way by any additional modes. Regular instructions have a single stack effect which is modified in a predictable way by any additional modes.
@ -70,9 +70,15 @@ In \fIreturn\fP mode the stacks are reversed. Effects on \fBwst\fP will instead
In \fIkeep\fP mode all the values on the left-hand side of the stack effect will also appear on the right-hand side before the outputs. For example, \fBSWP\fP is \fB(x y -- y x)\fP but \fBSWPk\fP is \fB(x y -- x y y x)\fP. In \fIkeep\fP mode all the values on the left-hand side of the stack effect will also appear on the right-hand side before the outputs. For example, \fBSWP\fP is \fB(x y -- y x)\fP but \fBSWPk\fP is \fB(x y -- x y y x)\fP.
.SH REGULAR INSTRUCTIONS
.BR
.SS INC .SS INC
( x -- x+1 ) ( x -- x+1 )
Overflow will be truncated, so \fB#ff INC\fP will evaluate to \fB0x00\fP.
.SS POP .SS POP
( x -- ) ( x -- )
@ -134,12 +140,12 @@ Store the next address to execute before unconditionally updating the program co
.SS LDZ .SS LDZ
( zp^ -- x ) ( zp^ -- x )
Load data from a zero-page address (\fB0x0000 - 0x00ff\fP). Load data from a zero-page address (\fB0x00 - 0xff\fP).
.SS STZ .SS STZ
( x zp^ -- ) ( x zp^ -- )
Store data at a zero-page address (\fB0x0000 - 0x00ff\fP). Store data at a zero-page address (\fB0x00 - 0xff\fP).
.SS LDR .SS LDR
( rel^ -- x ) ( rel^ -- x )
@ -223,11 +229,9 @@ Right shifts are unsigned (they introduce zero bits); there are no signed shifts
Since the largest values (\fIshort\fP) are 16-bit, one nibble (\fB0x0 - 0xf\fP) is sufficient to express all useful left or right shifts. Since the largest values (\fIshort\fP) are 16-bit, one nibble (\fB0x0 - 0xf\fP) is sufficient to express all useful left or right shifts.
Right: \fB#ff #03 SFT\fP evaluates to \fB0x1f\fP. Right: \fB#ff #03 SFT\fP evaluates to \fB0x1f\fP
Left: \fB#ff #20 SFT\fP evaluates to \fB0xfc\fP
Left: \fB#ff #20 SFT\fP evaluates to \fB0xfc\fP. Both: \fB#ff #23 SFT\fP evaluates to \fB0x7c\fP
Both: \fB#ff #23 SFT\fP evaluates to \fB0x7c\fP.
.SH SPECIAL INSTRUCTIONS .SH SPECIAL INSTRUCTIONS
@ -264,3 +268,16 @@ The "literal" instructions are used to push new data onto the stacks. They inter
(The instruction pointer will be moved forward 1-2 bytes, past the literal data.) (The instruction pointer will be moved forward 1-2 bytes, past the literal data.)
Literal values can be updated dynamically using store:
#abcd ;x STA2
( later on... )
LIT2 [ @x $2 ]
.SH SEE ALSO
https://wiki.xxiivv.com/site/uxntal_opcodes.html \fIUxntal Opcodes\fP
https://wiki.xxiivv.com/site/uxntal_syntax.html \fIUxntal Syntax\fP
https://wiki.xxiivv.com/site/uxntal_modes.html \fIUxntal Modes\fP
https://wiki.xxiivv.com/site/uxntal_immediate.html \fIImmediate opcodes\fP
https://wiki.xxiivv.com/site/varvara.html \fIVarvara\fP