skiselev

Ericsson PC - BIOS / Keyboard Interface Reverse-Engineering

Hardware

• An 8251 USART next the 8255 PPI. Apparently it is used for the keyboard interfacing
• BIOS size 16 KiB, two 2764 EPROMs

BIOS Code

• All numeric values are in hexadecimal

skiselev

; DIAMONDS.ASM - PRINT DIAMONDS ON THE CONSOLE
; VINTAGE COMPUTING CHRISTMAS CHALLENGE 2023 (VC3 2023)
; WRITTEN BY SERGEY KISELEV <[email protected]>
;
; RUNS ON CP/M SYSTEMS WITH INTEL 8080, ZILOG Z80
;   AND COMPATIBLE PROCESSORS
;
; BUILDING AND RUNNIG STEPS:
; A>ASM DIAMONDS
; A>LOAD DIAMONDS

skiselev

; STARP.ASM - PRINT CHRISTMAS STAR ON THE CONSOLE
; VINTAGE COMPUTING CHRISTMAS CHALLENGE 2022 (VC3 2022)
; WRITTEN BY SERGEY KISELEV <[email protected]>
;
; RUNS ON CP/M SYSTEMS WITH INTEL 8080, ZILOG Z80
;   AND COMPATIBLE PROCESSORS
;
; BUILDING AND RUNNIG STEPS:
; A>ASM STARP
; A>LOAD STARP

skiselev

; SNWFLK.ASM - PRINT CHRISTMAS STAR ON THE CONSOLE
; WRITTEN BY SERGEY KISELEV <[email protected]>
;
; RUNS ON CP/M SYSTEMS WITH INTEL 8080, ZILOG Z80
;   AND COMPATIBLE PROCESSORS
;
; BUILDING AND RUNNIG STEPS:
; A>ASM SNWFLK
; A>LOAD SNWFLK
; A>SNWFLK