A small but heartfelt demo celebrating the 50th birthday of the legendary MOS KIM-1 🖥️✨
The KIM-1 first became available in January 1976 —
three months before the Apple I 🍎 and one month after its sibling, the TIM.
An incredible milestone in early microcomputer history!
For this demo, I’ve gathered and connected a few components that were scattered across my repositories 🧩.
The goal is not just to look back, but to celebrate, experiment, and build together.
I warmly invite fellow retro-computing enthusiasts and comrades-in-arms 🤝
to jump in, contribute ideas, add modules, demos, or improvements, and help this project grow.
Let’s keep the spirit of early computing alive 🚀
🎉 HAPPY BIRTHDAY, KIM-1! 🎉
Wishing you — and all of us — a fantastic and hacky Year 2026 🥳✨
kim-1_demo.mp4
Things that are very useful in this code:
Take any coordinates in HEX out of the memory and use them to place your cursor. The problem is, that to position your cursur, you need to send the x/y coordinates as single chars to the terminal program, like (ESC)[xx;yyH - Imagine just having hex data, i.e. $20 (32 dec) and you need to send a 3 and a 2 separated to your terminal... This routine will do it - seperate the tens from the ones. Now you can like draw a rectangle, a circle or whatever. You can start a painting program if you like.
; ANSI Cursor positionieren (Row ; Col)
GOTOXY:
LDA #$1B ; ESC
JSR CHOUT
LDA #$5B ; '['
JSR CHOUT
LDA CURY ; Row zuerst
JSR PUTDEC
LDA #$3B ; ';'
JSR CHOUT
LDA CURX ; Column danach
JSR PUTDEC
LDA #$48 ; 'H'
JSR CHOUT
RTS
; Dezimalzahl ausgeben (A-Register, 0-99)
; Benutzt TEMP als temporäre Variable
PUTDEC:
STA TEMP ; Wert sichern
LDY #0 ; Zehner-Zähler
PUTDEC_T: CMP #10
BCS PUTDEC_S ; >= 10
JMP PUTDEC_D
PUTDEC_S: SEC
SBC #10
INY
JMP PUTDEC_T
PUTDEC_D: ; A enthält Einer
TAX ; Einer nach X retten
TYA ; Zehner
BNE PUTDEC_Z ; Wenn nicht 0
JMP PUTDEC1
PUTDEC_Z: CLC
ADC #$30 ; In ASCII umwandeln
JSR CHOUT
PUTDEC1: TXA ; Einer zurück
CLC
ADC #$30 ; In ASCII umwandeln
JSR CHOUT
LDA TEMP ; Original wiederherstellen
RTS