pato-z80-home-computer/assembly/bios/main.asm
Daniele Verducci (ZenPenguin) 33fd225a0f WIP: Monitor asm file stub
2020-11-23 08:47:23 +01:00

108 lines
2.0 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'
; 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:
;call Lcd_init
; position to line 2 char 3
;ld b, 1
;ld c, 1
;call Lcd_locate
; I/O TEST
; write characters to display
ld bc, SYSINIT_GREETING
call Lcd_print ; write string to screen
_io_test_loop:
in a, (IO_0) ; legge dal terminale
cp 0
jp z, _io_test_loop
;sub a, 32 ; trasforma in maiuscola (ascii - 32)
out (IO_0), a ; scrive la lettera trasformata
jp _io_test_loop
halt
; poll keyboard
;_poll_keyb:
;call Keyb_read
;jp _poll_keyb