improve formatting on small screens
This commit is contained in:
parent
93e75ca024
commit
b497e72d56
115
uxntal.7
115
uxntal.7
|
|
@ -75,14 +75,18 @@ Regular instructions have a single stack effect which is modified in a predictab
|
|||
|
||||
For example the generic effect for \fBADD\fP is ( x y -- x+y ). The eight combinations of modes have the following effects:
|
||||
|
||||
\fBADD\fP ( x^ y^ -- x+y^ ) sum two bytes using \fBwst\fP
|
||||
\fBADDr\fP ( [x^ y^] -- [x+y^] ) sum two bytes using \fBrst\fP
|
||||
\fBADD2\fP ( x* y* -- x+y* ) sum two shorts using \fBwst\fP
|
||||
\fBADD2r\fP ( [x* y*] -- [x+y*] ) sum two shorts using \fBrst\fP
|
||||
\fBADDk\fP ( x^ y^ -- x^ y^ x+y^ ) sum two bytes using \fBwst\fP, retain arguments
|
||||
\fBADDkr\fP ( [x^ y^] -- [x^ y^ x+y^] ) sum two bytes using \fBrst\fP, retain arguments
|
||||
\fBADD2k\fP ( x* y* -- x* y* x+y* ) sum two shorts using \fBwst\fP, retain arguments
|
||||
\fBADD2kr\fP ( [x* y*] -- [x* y* x+y*] ) sum two shorts using \fBrst\fP, retain arguments
|
||||
.nf
|
||||
|
||||
\fBADD\fP ( x^ y^ -- x+y^ ) sum bytes from \fBwst\fP
|
||||
\fBADDr\fP ( [x^ y^] -- [x+y^] ) sum bytes from \fBrst\fP
|
||||
\fBADD2\fP ( x* y* -- x+y* ) sum shorts from \fBwst\fP
|
||||
\fBADD2r\fP ( [x* y*] -- [x+y*] ) sum shorts from \fBrst\fP
|
||||
\fBADDk\fP ( x^ y^ -- x^ y^ x+y^ ) sum and keep bytes from \fBwst\fP
|
||||
\fBADDkr\fP ( [x^ y^] -- [x^ y^ x+y^] ) sum and keep bytes from \fBrst\fP
|
||||
\fBADD2k\fP ( x* y* -- x* y* x+y* ) sum and keep shorts from \fBwst\fP
|
||||
\fBADD2kr\fP ( [x* y*] -- [x* y* x+y*] ) sum and keep shorts from \fBrst\fP
|
||||
|
||||
.fi
|
||||
|
||||
Thus for regular instructions writing a "generic" effect (leaving sigils off values whose size depends on \fIshort mode\fP) is sufficient to describe its behavior across all eight variations. Note that some instructions always read values of a fixed size. For example the boolean condition read by \fBJCN\fP is always one byte, no matter what modes are used.
|
||||
|
||||
|
|
@ -98,77 +102,65 @@ We consider the top of the stack to be the first value of the stack, and count b
|
|||
|
||||
.BR
|
||||
|
||||
.SS INC
|
||||
( x -- x+1 )
|
||||
.SS INC ( x -- x+1 )
|
||||
|
||||
Increment the top value of the stack by 1.
|
||||
|
||||
Overflow will be truncated, so \fB#ff INC\fP will evaluate to \fB0x00\fP.
|
||||
|
||||
.SS POP
|
||||
( x -- )
|
||||
.SS POP ( x -- )
|
||||
|
||||
Remove the top value of the stack.
|
||||
|
||||
\fBPOPk\fP is guaranteed to have no effect (it will not change the stack).
|
||||
|
||||
.SS NIP
|
||||
( x y -- y )
|
||||
.SS NIP ( x y -- y )
|
||||
|
||||
Remove the second value of the stack.
|
||||
|
||||
\fBNIPk\fP is guaranteed to have no effect (it will not change the stack).
|
||||
|
||||
.SS SWP
|
||||
( x y -- y x )
|
||||
.SS SWP ( x y -- y x )
|
||||
|
||||
Swap the top two values of the stack.
|
||||
|
||||
.SS ROT
|
||||
( x y z -- y z x )
|
||||
.SS ROT ( x y z -- y z x )
|
||||
|
||||
Rotate the top three values of the stack. The lowest becomes the top and the others are each shifted down one place.
|
||||
|
||||
.SS DUP
|
||||
( x -- x x )
|
||||
.SS DUP ( x -- x x )
|
||||
|
||||
Place a copy of the top value of the stack on top of the stack.
|
||||
|
||||
.SS OVR
|
||||
( x y -- x y x )
|
||||
.SS OVR ( x y -- x y x )
|
||||
|
||||
Place a copy of the second value of the stack on top of the stack.
|
||||
|
||||
.SS EQU
|
||||
( x y -- x==y^ )
|
||||
.SS EQU ( x y -- x==y^ )
|
||||
|
||||
Test whether the top two values of the stack are equal.
|
||||
|
||||
Result is guaranteed to be boolean (\fB0x00\fP or \fB0x01\fP).
|
||||
|
||||
.SS NEQ
|
||||
( x y -- x!=y^ )
|
||||
.SS NEQ ( x y -- x!=y^ )
|
||||
|
||||
Test whether the top two values of the stack are not equal.
|
||||
|
||||
Result is guaranteed to be boolean (\fB0x00\fP or \fB0x01\fP).
|
||||
|
||||
.SS GTH
|
||||
( x y -- x>y^ )
|
||||
.SS GTH ( x y -- x>y^ )
|
||||
|
||||
Test whether the second value of the stack is greater than the top.
|
||||
|
||||
Result is guaranteed to be boolean (\fB0x00\fP or \fB0x01\fP).
|
||||
|
||||
.SS LTH
|
||||
( x y -- x<y^ )
|
||||
.SS LTH ( x y -- x<y^ )
|
||||
|
||||
Test whether the second value of the stack is less than the top.
|
||||
|
||||
Result is guaranteed to be boolean (\fB0x00\fP or \fB0x01\fP).
|
||||
|
||||
.SS JMP
|
||||
( x -- ; pc <- x )
|
||||
.SS JMP ( x -- ; pc <- x )
|
||||
|
||||
Jump to a location.
|
||||
|
||||
|
|
@ -178,15 +170,13 @@ It is common to \fBJMP\fP with boolean bytes (0-1) to handle simple conditionals
|
|||
|
||||
@max ( x^ y^ -- max^ ) GTHk JMP SWP POP JMP2r
|
||||
|
||||
.SS JCN
|
||||
( x bool^ -- ; pc <- x if bool )
|
||||
.SS JCN ( x bool^ -- ; pc <- x if bool )
|
||||
|
||||
Jump to a location when a condition is true.
|
||||
|
||||
The program counter (\fIpc\fP) is updated when \fIbool\fP is non-zero. When \fIx\fP is a byte, it is treated as relative (\fBpc += x\fP) and when \fIx\fP is a short it is treated as absolute (\fBpc = x\fP).
|
||||
|
||||
.SS JSR
|
||||
( x -- [pc+1*] )
|
||||
.SS JSR ( x -- [pc+1*] )
|
||||
|
||||
Jump to a location, saving a reference to return to.
|
||||
|
||||
|
|
@ -194,82 +184,69 @@ Stores the next address to execute before unconditionally updating the program c
|
|||
|
||||
The saved address will always be a short regardless of \fIshort mode\fP.
|
||||
|
||||
.SS STH
|
||||
( x -- [x] )
|
||||
.SS STH ( x -- [x] )
|
||||
|
||||
Move the top value of the stack to the return stack.
|
||||
|
||||
.SS LDZ
|
||||
( zp^ -- x )
|
||||
.SS LDZ ( zp^ -- x )
|
||||
|
||||
Load data from a zero-page address (\fB0x00 - 0xff\fP).
|
||||
|
||||
.SS STZ
|
||||
( x zp^ -- )
|
||||
.SS STZ ( x zp^ -- )
|
||||
|
||||
Store data at a zero-page address (\fB0x00 - 0xff\fP).
|
||||
|
||||
.SS LDR
|
||||
( rel^ -- x )
|
||||
.SS LDR ( rel^ -- x )
|
||||
|
||||
Load data from a relative address (\fBpc + x\fP).
|
||||
|
||||
Note that unlike \fBLDZk\fP and \fBLDAk\fP the \fBLDRk\fP instruction is not very useful, since a relative address is usually only meaningful when run from a particular address (i.e. for a particular \fIpc\fP value).
|
||||
|
||||
.SS STR
|
||||
( x rel^ -- )
|
||||
.SS STR ( x rel^ -- )
|
||||
|
||||
Store data at a relative address (\fBpc + x\fP).
|
||||
|
||||
Note that unlike \fBSTZk\fP and \fBSTAk\fP the \fBSTRk\fP instruction is not very useful, since a relative address is usually only meaningful when run from a particular address (i.e. for a particular \fIpc\fP value).
|
||||
|
||||
.SS LDA
|
||||
( abs* -- x )
|
||||
.SS LDA ( abs* -- x )
|
||||
|
||||
Load data from an absolute address (\fB0x0000 - 0xffff\fP).
|
||||
|
||||
.SS STA
|
||||
( x abs* -- )
|
||||
.SS STA ( x abs* -- )
|
||||
|
||||
Store data at an absolute address (\fB0x0000 - 0xffff\fP).
|
||||
|
||||
.SS DEI
|
||||
( dev^ -- x )
|
||||
.SS DEI ( dev^ -- x )
|
||||
|
||||
Read data from a device port (\fB0x00 - 0xff\fP).
|
||||
|
||||
Reading from some ports may have an effect on the underlying VM; in other cases it will simply read values from device memory. See Varvara device documentation for more details.
|
||||
|
||||
.SS DEO
|
||||
( x dev^ -- )
|
||||
.SS DEO ( x dev^ -- )
|
||||
|
||||
Write data to a device port (\fB0x00 - 0xff\fP).
|
||||
|
||||
Writing to some ports may have an effect on the underlying VM; in other cases it will simply write values to device memory. See Varvara device documentation for more details.
|
||||
|
||||
.SS ADD
|
||||
( x y -- x+y )
|
||||
.SS ADD ( x y -- x+y )
|
||||
|
||||
Add the top two values of the stack.
|
||||
|
||||
Overflow will be truncated, so \fB#ff #03 ADD\fP will evaluate to \fB0x02\fP.
|
||||
|
||||
.SS SUB
|
||||
( x y -- x-y )
|
||||
.SS SUB ( x y -- x-y )
|
||||
|
||||
Subtract the top of the stack from the second value of the stack.
|
||||
|
||||
Underflow will be truncated, so \fB#01 #03 SUB\fP will evaluate to \fB0xfe\fP.
|
||||
|
||||
.SS MUL
|
||||
( x y -- xy )
|
||||
.SS MUL ( x y -- xy )
|
||||
|
||||
Multiply the top two values of the stack.
|
||||
|
||||
Overflow will be truncated, so \fB#11 #11 MUL\fP will evaluate to \fB0x21\fP.
|
||||
|
||||
.SS DIV
|
||||
( x y -- x/y )
|
||||
.SS DIV ( x y -- x/y )
|
||||
|
||||
Divide the second value of the stack by the top of the stack.
|
||||
|
||||
|
|
@ -281,23 +258,19 @@ Unlike \fBADD\fP, \fBSUB\fP, and \fBMUL\fP, \fBDIV\fP does not behave correctly
|
|||
|
||||
There is no \fIremainder\fP instruction, but the phrase \fBDIVk MUL SUB\fP can be used to compute the remainder.
|
||||
|
||||
.SS AND
|
||||
( x y -- x&y )
|
||||
.SS AND ( x y -- x&y )
|
||||
|
||||
Compute the bitwise union of the top two values of the stack.
|
||||
|
||||
.SS ORA
|
||||
( x y -- x|y )
|
||||
.SS ORA ( x y -- x|y )
|
||||
|
||||
Compute the bitwise intersection of the top two values of the stack.
|
||||
|
||||
.SS EOR
|
||||
( x y -- x^y )
|
||||
.SS EOR ( x y -- x^y )
|
||||
|
||||
Compute the bitwise exclusive-or (\fIxor\fP) of the top two values of the stack.
|
||||
|
||||
.SS SFT
|
||||
( x rl^ -- (x>>l)<<r )
|
||||
.SS SFT ( x rl^ -- (x>>l)<<r )
|
||||
|
||||
Compute a bit shift of the second value of the stack; the directions and distances are determined by the top value of the stack.
|
||||
|
||||
|
|
@ -325,7 +298,7 @@ The "immediate jump" instructions are produced by the assembler. They interpret
|
|||
|
||||
\fBJMI\fP ( -- ) jump to \fIaddr\fP unconditionally
|
||||
\fBJCI\fP ( bool^ -- ) jump to \fIaddr\fP if \fIbool\fP is non-zero
|
||||
\fBJSI\fP ( -- [pc*] ) jump to \fIaddr\fP saving the current address (\fIpc\fP) on the return stack
|
||||
\fBJSI\fP ( -- [pc*] ) jump to \fIaddr\fP saving the current address (\fIpc\fP) on \fIrst\fP
|
||||
|
||||
(The instruction pointer will be moved forward 2 bytes, past the relative address.)
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue