Improved docs

This commit is contained in:
neauoire 2021-02-08 14:49:45 -08:00
parent 635d3de67b
commit 5e80946097
2 changed files with 12 additions and 18 deletions

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@ -1,32 +1,26 @@
# Uxn
A stack-based VM, written in ANSI C.
## Build
```
cc uxn.c -std=c89 -Os -DNDEBUG -g0 -s -Wall -Wno-unknown-pragmas -o uxn
```
A [stack-based VM](https://wiki.xxiivv.com/site/uxn.html), written in ANSI C.
## Assembly Syntax
### Write
- `;variable`, set a label to an assigned address
- `:const`, set a label to a constant short
- `@label`, set a label to an address
- `;variable`, automatically assign an address to a label.
- `:const FFCF`, manually assign an address to a label.
- `@label`, assign the current address to a label.
### Read
- `,literal`, push label value to stack
- `.pointer`, read label value
- `,literal`, push label value to stack, prefixed with `LIT LEN`.
- `.pointer`, push label value to stack.
### Special
- `( comment )`, toggle parsing on/off
- `|0010`, move to position in the program
- `"hello`, push literal bytes for word "hello"
- `#04`, a zero-page address, equivalent to `,0004`
- `( comment )`, toggle parsing on/off.
- `|0010`, move to position in the program.
- `"hello`, push literal bytes for word "hello".
- `#04`, a zero-page address, equivalent to `,0004`.
### Operator modes
@ -68,7 +62,7 @@ BRK
|FFFA .RESET .FRAME .ERROR
```
## Mission
## TODOs
### Assembler

2
uxn.c
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@ -27,7 +27,7 @@ void wspush16(Uxn *u, Uint16 s) { wspush8(u,s >> 8); wspush8(u,s & 0xff); }
Uint16 wspop16(Uxn *u) { return wspop8(u) + (wspop8(u) << 8); }
Uint16 wspeek16(Uxn *u, Uint8 o) { return bytes2short(u->wst.dat[u->wst.ptr - o], u->wst.dat[u->wst.ptr - o + 1]); }
void rspush16(Uxn *u, Uint16 a) { u->rst.dat[u->rst.ptr++] = a; }
Uint16 mempeek16(Uxn *u, Uint16 s) { return (u->ram.dat[s] << 8) + (u->ram.dat[s+1] & 0xff); }
Uint16 mempeek16(Uxn *u, Uint16 s) { return (u->ram.dat[s] << 8) + (u->ram.dat[s + 1] & 0xff); }
/* I/O */
void op_brk(Uxn *u) { setflag(&u->status,FLAG_HALT, 1); }