pato-z80-home-computer/assembly/bios/main.asm
Daniele Verducci (ZenPenguin) 3d7610e113 WIP Monitor
2020-11-25 08:53:41 +01:00

102 lines
1.8 KiB
NASM

jp Sysinit ; Startup vector: DO NOT MOVE! Must be the first instruction
; Pat80 BIOS v0.01
; @author: Daniele Verducci
;
; MEMORY MAP
; ROM is at 0x0000
; RAM is at 0x8000
; SYSTEM VAR SPACE: 0x8000 - 0x8FFF (4kb)
; DRIVERS VAR SPACE: 0x9000 - 0x9FFF (4kb)
; APPLICATION VAR SPACE: 0xA000 - 0xFFFF (24kb)
; I/O MAP
; I/O 0 (0x00 - 0x1F) LCD (uses 0x00 and 0x01)
; I/O 1 (0x20 - 0x3F)
; I/O 2 (0x40 - 0x5F)
; I/O 3 (0x60 - 0x7F)
; I/O 4 (0x80 - 0x9F)
; I/O 5 (0xA0 - 0xBF)
; I/O 6 (0xC0 - 0xDF)
; I/O 7 (0xE0 - 0xFF)
; MEMORY CONFIGURATION
SYS_VAR_SPACE: EQU 0x8000
DRV_VAR_SPACE: EQU 0x9000
APP_VAR_SPACE: EQU 0xA000
; SYSTEM CONFIGURATION
IO_0: EQU 0x00
IO_1: EQU 0x20
IO_2: EQU 0x40
IO_3: EQU 0x60
IO_4: EQU 0x80
IO_5: EQU 0xA0
IO_6: EQU 0xC0
IO_7: EQU 0xE0
; CONSTANTS
SYSINIT_GREETING:
DB "Pat80",10,0 ; null terminated string
;include 'driver_hd44780.asm'
;include 'driver_keyboard.asm'
include 'driver_arduino_terminal.asm'
include 'monitor.asm'
; SYSTEM CALLS
; User I/O
; Prints string
; @param BC Pointer to a null-terminated string first character
Print:
call Term_print
ret
; Writes a single character
; @param A Value of character to print
Printc:
call Term_printc
ret
; Reads a single character
; @return A The read character
Readc:
call Term_readc
ret
; Reads a line
; @return BC The pointer to a null-terminated read string
Readline:
call Term_readline
ret
; System initialization
Sysinit:
ld bc, SYSINIT_GREETING
call Print
_io_test_loop:
call Readline
call Print
; call Printc
; call Readline
; ld a, (bc)
; cp a, 0
; jp z, _io_test_loop
; ld (APP_VAR_SPACE), bc
; ld bc, SAYS
; call Print
; ld bc, (APP_VAR_SPACE)
; call Print
jp _io_test_loop