225 lines
5.4 KiB
NASM
225 lines
5.4 KiB
NASM
;----------------------------------------------------------------
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;Z8C Homebrew Computer Monitor
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;by Dennis Gunia (01/2023)
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;----------------------------------------------------------------
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;================================================================
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; Memory areas
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;================================================================
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SYS_RAM_START equ 0x4000
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SYS_BUF_START equ 0x4010
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PRG_RAM_START equ 0x4110
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PRG_RAM_TOP equ 0xFF00
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STACK_RAM_TOP equ 0xFFFF
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;================================================================
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; Terminal configuration
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;================================================================
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VAR_CONSOLE_CONF equ 0x0F ;CPU/16 Clock @ 230402.5625/s
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VAR_CONSOLE_BAUD equ 24 ;BAUD timer constant
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;CLK/TRG Clock @ 1843220.5/s
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; -> 0x16 : 14400
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;CPU/16 Clock @ 230402.5625/s
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; -> 12 : 19200
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; -> 24 : 9600
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;================================================================
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; Includes (1/2)
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;================================================================
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; include IO device addresses
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.include "addresses.s"
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;================================================================
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; RST Vectors for BASIC
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;================================================================
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org 0x0000
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RST_00: ;Hardware Restart
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jp BOOT_PHASE0
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org 0x0008
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RST_08 ;Print Char
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jp EXEC_RST_08
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org 0x0010
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RST_10 ;receive char
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jp EXEC_RST_10
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org 0x0018
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RST_18 ;Buffer length
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jp EXEC_RST_18
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;================================================================
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; Default interrupt vectors
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;================================================================
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INT_VEC:
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org 0x0044
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;DEFW EXEC_INT_VDP
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;================================================================
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; Memory layout
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;================================================================
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mon_var_template_sof .EQU mon_var_template + 1024
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mon_var_template:
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phase SYS_RAM_START
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interrupt_vectors:
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defs 256
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var_buffer_conin_data: ;contains console input
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defs 256
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var_buffer_conin_in: ;pointer to write position of buffer
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defb 0
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var_buffer_conin_out: ;pointer to read position of buffer
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defb 0
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var_buffer_conin_sts:
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defb 0
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var_buffer_conout:
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defb 0
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var_buffer_len:
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defb 0
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var_last_char:
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defb 0
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var_curserx:
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defb 0
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var_cursery:
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defb 0
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var_curserstate:
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defb 0
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var_curseron:
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defb 0
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var_curserchar:
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defb 0
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var_curserlastaddr:
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defw 0
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var_pio_present:
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defb 0
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var_apu_present:
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defb 0
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var_scratch:
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defs 16 ;16 bytes space for scratch vars
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var_ps2mem:
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defs 16 ;16 bytes space for scratch vars
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var_dir:
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defs 80
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var_input:
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defs 80
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var_idebuffer:
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defs 768
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dephase
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mon_var_template_end:
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nop
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;================================================================
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; Start of monitor
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;================================================================
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.include "ref.s" ;static bios calls for programs
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BOOT_PHASE0: ;Setup Hardware
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;Setup Stack-Pointer
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ld sp, STACK_RAM_TOP
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;Disable Interrupts
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di
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;Setup PIO on MIO Board
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LD A,0xCF
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OUT (CS_PIO_AC), A
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LD A,11110111b ;All pins inputs except speaker
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OUT (CS_PIO_AC), A
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LD A,00000011B ;Preset I2C pins to high
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OUT (CS_PIO_AC), A
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;Set variables
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ld (var_curserstate),a
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ld (var_curseron),a
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ld a, " "
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ld (var_curserchar),a
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;Enable interupts
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call intctrl_init
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;Initialize Console (Serial-Port)
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call CONSOLE_INIT
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;clear memory area
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ld hl, [mon_var_template_sof]
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ld bc, [mon_var_template_end-mon_var_template_sof]
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ld de, [mon_var_template_sof+1]
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xor a
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ld (hl),a
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ldir
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jp BOOT_PHASE2 ;skip rest of table init
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BOOT_PHASE1: ;Copy default values to RAM
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ld hl,mon_var_template + 1024
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ld de,mon_var_template_end
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ld bc,SYS_RAM_START
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BOOT_PHASE1_LOOP:
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ld a,(hl) ;copy values
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ld (bc),a
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inc hl
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inc bc
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push hl ;check if end is reached
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sbc hl,de
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pop hl
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jp nz, BOOT_PHASE1_LOOP
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;template copy done
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BOOT_PHASE2: ;Hardware initialized.
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; Print banner
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call print_clear
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ld hl, [STR_Banner_Start]
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call print_str
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; Power-On Self Tests
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call POST_START
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; Detect IDE drives
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call ideif_init_all
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; Beep after start
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LD DE,0x40
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LD BC,0x48
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CALL beep
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xor a ;set dir to empty
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ld (var_dir),a
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ld (var_dir+1),a
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;enable interrupts
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ei
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; Start commandline
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jp COMMAND
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; This instruction should never be reached
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halt
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;================================================================
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; Includes (2/2)
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;================================================================
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.include "console.s"
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.include "conversions.s"
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.include "disassembler.s"
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.include "disassembler_table.s"
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.include "rst.s"
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.include "beep.s"
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.include "kdrv_ide8255.s" ;include ide interface driver.
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.include "kdrv_ideif.s" ;include ide driver.
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.include "kdrv_siic.s"
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.include "kdrv_int.s"
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.include "kdrv_sio.s"
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.include "prettydump.s"
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.include "command.s"
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.include "cmd_mem.s"
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.include "cmd_io.s"
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.include "cmd_date.s"
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.include "cmd_disk.s"
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.include "post.s"
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.include "fat16.s"
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.include "fat16_cmd.s"
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;================================================================
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; Strings
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;================================================================
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STR_Banner_Start:
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db "Z8C Monitor V2.1 by Dennis Gunia (2022-2024)",0
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