implement prefix calculator

calculator/README.md

@@ -0,0 +1,31 @@
+# Calculator
+
+This program accepts an arithmetic expression in prefix notation
+on standard input and prints the result on standard output.
+
+Supported operations:
+
+- Addition
+- Subtraction
+- Multiplication
+- Division
+
+All calculations are preformed on Integers in range $[-2^{23}, 2^{23} - 1]$. Negative numbers can be written as `(- 0 n)`, where `n` is the number
+
+Here are some examples:
+
+```{bash}
+(* 21 2)
+00000042
+(/ 6 (* 2 (+ 2 1)))
+00000001
+(* (/ 6 2) (+ 2 1))
+00000009
+(- 33 (* 4 25))
+-00000067
+
+```
+
+- Source code: calc.asm
+- Frequency: any (faster is faster)
+- Author: Jakob Jesenko, 2026

calculator/calc.asm

@@ -0,0 +1,193 @@
+calc    START   0
+nextln  LDA	#stack
+        STA	sp
+        CLEAR	A
+        STA	ldigit
+readlp  TD      stdin
+        JEQ     readlp
+        CLEAR	A
+        RD      stdin
+        COMP    #0
+        JEQ     halt
+        COMP	white   .whitespace (parse number?)
+        JEQ	newexp
+        COMP    opn     . (
+        JEQ	newexp
+        COMP	cls     . )
+        JEQ	endexp
+        COMP	plus    . +
+        JEQ	pplus
+        COMP	minus   . -
+        JEQ	pminus
+        COMP	times   . *
+        JEQ	ptimes
+        COMP	slash   . /
+        JEQ	pslash
+        COMP	lnfeed  . \n
+        JEQ	prtres
+        J	pdigit
+
+
+newexp  CLEAR	A
+        STA	ldigit
+        J	readlp
+endexp  CLEAR	A
+        STA	ldigit
+        LDA	sp
+        SUB	#3
+        STA	sp
+        LDS	@sp
+        SUB	#3
+        STA	sp
+        LDT	@sp
+        SUB	#3
+        STA	sp
+        LDA	@sp
+        COMP	plus    . +
+        JEQ	xplus
+        COMP	minus   . -
+        JEQ	xminus
+        COMP	times   . *
+        JEQ	xtimes
+        COMP	slash   . /
+        JEQ	xslash
+pres    STT	@sp
+        LDA	sp
+        ADD	#3
+        STA	sp
+        J	readlp
+
+pplus   CLEAR	A
+        STA	ldigit
+        LDA	plus
+        STA	@sp
+        LDA	sp
+        ADD	#3
+        STA	sp
+        J	readlp
+pminus  CLEAR	A
+        STA	ldigit
+        LDA	minus
+        STA	@sp
+        LDA	sp
+        ADD	#3
+        STA	sp
+        J	readlp
+ptimes  CLEAR	A
+        STA	ldigit
+        LDA	times
+        STA	@sp
+        LDA	sp
+        ADD	#3
+        STA	sp
+        J	readlp
+pslash  CLEAR	A
+        STA	ldigit
+        LDA	slash
+        STA	@sp
+        LDA	sp
+        ADD	#3
+        STA	sp
+        J	readlp
+pdigit  SUB	zero
+        RMO	A,B
+        LDA	ldigit
+        COMP	#1
+        JEQ	pndgit
+pcdgit  RMO	B,A
+        STA	@sp
+        LDA	sp
+        ADD	#3
+        STA	sp
+        LDA	#1
+        STA	ldigit
+        J	readlp
+pndgit  LDA	sp
+        SUB	#3
+        STA	sp
+        LDA	@sp
+        MUL	#10
+        ADDR	A,B
+        J	pcdgit
+
+xplus   ADDR	S,T
+        J	pres
+xminus  SUBR	S,T
+        J	pres
+xtimes  MULR	S,T
+        J	pres
+xslash  DIVR	S,T
+        J	pres
+
+prtres  LDB	#base
+        STB	bp
+        LDA	sp
+        SUB	#3
+        STA	sp
+        LDA	@sp
+        AND	negsgn
+        COMP	negsgn
+        JEQ	prtneg
+prtnxt  LDA	@bp
+        COMP	#0
+        JEQ	prtext
+        LDA	@sp
+        DIV	@bp
+        ADD	zero
+        WD	stdout
+        SUB	zero
+        LDB	@bp
+        MULR	B,A
+        LDB	@sp
+        SUBR	A,B
+        STB	@sp
+        LDA	bp
+        ADD	#3
+        STA	bp
+        J	prtnxt
+prtext
+        LDA	lnfeed
+        WD	stdout
+        J	nextln
+prtneg
+        LDA	minus
+        WD	stdout
+        LDA	#0
+        SUB	#1
+        LDS	@sp
+        MULR	S,A
+        STA	@sp
+        J	prtnxt
+
+
+
+halt    J       halt
+
+stdin   BYTE    0x00
+stdout  BYTE    0x01
+zero    WORD    48
+lnfeed  WORD    10
+white   WORD    32
+opn     WORD    40
+cls     WORD    41
+plus    WORD    43
+minus   WORD    45
+times   WORD    42
+slash   WORD    47
+
+ldigit  WORD    0
+negsgn  WORD    0x800000
+
+bp      RESW    1
+base    WORD    10000000
+        WORD    1000000
+        WORD    100000
+        WORD    10000
+        WORD    1000
+        WORD    100
+        WORD    10
+        WORD    1
+        WORD    0
+
+sp      RESW    1
+stack   RESW    256

ppm viewer/README.md

@@ -1,9 +1,10 @@
 # PPM image viewer
 
-Reads a ppm image from an input device (AF.dev by default) 
+Reads a ppm image from an input device (AF.dev by default)  
 and displays it on SicTools builtin graphical screen.
 
 To resize and convert your image you can use ffmpeg:
+
 ```{sh}
 ffmpeg -i image.png -vf scale="64x-1" AF.ppm && mv AF.ppm AF.dev
 ```
@@ -13,4 +14,3 @@ ffmpeg -i image.png -vf scale="64x-1" AF.ppm && mv AF.ppm AF.dev
   - dimensions can be adjusted by changing their values in code
 - Frequency: any
 - Author: Jakob Jesenko, 2026
-