208 lines
2.8 KiB
NASM
208 lines
2.8 KiB
NASM
.org 0x400
|
|
screen: .equ 0x10000
|
|
reg: .equ 16
|
|
|
|
lshift: .equ 0xe1
|
|
rshift: .equ 0xe5
|
|
enter: .equ 0x28
|
|
backspace: .equ 0x2a
|
|
|
|
;;;;; Start
|
|
push on_key
|
|
setiv 5
|
|
setint 1
|
|
call clear_screen
|
|
call set_video
|
|
push msg
|
|
push screen
|
|
call print_to
|
|
wfi_loop: hlt
|
|
jmpr @wfi_loop
|
|
;;;;;
|
|
|
|
set_video:
|
|
push 30
|
|
storew reg + 10
|
|
push 40
|
|
storew reg + 13
|
|
ret
|
|
|
|
clear_screen:
|
|
push screen
|
|
#while
|
|
dup
|
|
lt screen + 40 * 30
|
|
#do
|
|
dup
|
|
swap 0
|
|
store
|
|
|
|
dup
|
|
add 40 * 30
|
|
swap 0b10010010
|
|
store
|
|
|
|
add 1
|
|
#end
|
|
pop
|
|
ret
|
|
|
|
print_to: ; ( msg addr -- )
|
|
pushr
|
|
#while
|
|
dup
|
|
load
|
|
#do
|
|
dup
|
|
load
|
|
peekr
|
|
store
|
|
popr
|
|
add 1
|
|
pushr
|
|
add 1
|
|
#end
|
|
pop
|
|
popr
|
|
pop
|
|
ret
|
|
|
|
on_key:
|
|
setint 1 ; this can be reentrant, doesn't hurt anything
|
|
call is_press ; check for press
|
|
#if
|
|
call is_ret
|
|
brnz @newline
|
|
call is_back
|
|
brnz @handle_backspace
|
|
call is_printable
|
|
brnz @putc
|
|
call is_shift
|
|
brnz @set_shift
|
|
; if backspace, clear cursor and dec
|
|
pop
|
|
ret
|
|
#else
|
|
call is_shift
|
|
brnz @clear_shift
|
|
pop
|
|
ret
|
|
#end
|
|
ret
|
|
|
|
newline:
|
|
loadw cursor
|
|
sub screen
|
|
add 40
|
|
dup
|
|
gt 40 * 30 - 1
|
|
#if
|
|
pop
|
|
push 40
|
|
#else
|
|
dup
|
|
mod 40
|
|
sub
|
|
#end
|
|
add screen
|
|
storew cursor
|
|
ret
|
|
|
|
handle_backspace:
|
|
loadw cursor
|
|
sub screen
|
|
dup
|
|
mod 40
|
|
#if
|
|
sub 1
|
|
add screen
|
|
dup
|
|
swap 32 ; a space
|
|
store
|
|
storew cursor
|
|
#else
|
|
pop
|
|
#end
|
|
ret
|
|
|
|
|
|
set_shift:
|
|
push shift_table
|
|
storew current_table
|
|
ret
|
|
|
|
clear_shift:
|
|
push default_table
|
|
storew current_table
|
|
ret
|
|
|
|
is_press: ; ( event -- key bool )
|
|
dup
|
|
and 0xff
|
|
swap
|
|
and 0xff00
|
|
ret
|
|
|
|
is_ret:
|
|
push enter
|
|
jmp is_key
|
|
|
|
is_back:
|
|
push backspace
|
|
jmp is_key
|
|
|
|
is_shift: ; ( key -- 1 ) or ( key -- key 0 )
|
|
push lshift
|
|
call is_key
|
|
brz @+2
|
|
ret 1
|
|
push rshift
|
|
jmp is_key
|
|
|
|
is_key: ; ( key1 key2 -- 1 ) or ( key1 key2 -- key1 0 )
|
|
swap
|
|
dup
|
|
pushr
|
|
sub
|
|
#unless ; they're equal
|
|
popr
|
|
pop
|
|
ret 1
|
|
#else ; they're not
|
|
popr
|
|
ret 0
|
|
#end
|
|
|
|
is_printable: ; ( key -- ch 1 ) or ( key -- key 0 )
|
|
dup
|
|
dup
|
|
gt 0x03
|
|
swap
|
|
lt 0x39
|
|
and
|
|
#if
|
|
sub 0x04
|
|
loadw current_table
|
|
add
|
|
load
|
|
ret 1
|
|
#end
|
|
ret 0
|
|
|
|
putc: ; ( ch -- ) (also modifies cursor)
|
|
loadw cursor
|
|
dup
|
|
pushr
|
|
store
|
|
popr
|
|
add 1
|
|
storew cursor
|
|
ret
|
|
|
|
default_table: .db "abcdefghijklmnopqrstuvwxyz1234567890???? -=[]\\?;'`,./"
|
|
shift_table: .db "ABCDEFGHIJKLMNOPQRSTUVWXYZ!@#$%^&*()???? _+{}|?:\"~<>?"
|
|
|
|
cursor: .db screen + 40
|
|
msg: .db "Type something:\0"
|
|
current_table: .db default_table
|