mirror of https://github.com/zxdos/zxuno.git
142 lines
5.9 KiB
NASM
142 lines
5.9 KiB
NASM
macro wreg dir, dato
|
|
rst $28
|
|
defb dir, dato
|
|
endm
|
|
|
|
output bootloader.rom
|
|
define zxuno_port $fc3b
|
|
define master_conf 0
|
|
define master_mapper 1
|
|
define flash_spi 2
|
|
define flash_cs 3
|
|
define joyconf 6
|
|
define scandbl_ctrl 11
|
|
|
|
di
|
|
ld sp, $bfff-67
|
|
ld de, $c761 ; tras el out (c), h de bffc se ejecuta
|
|
push de ; un rst 0 para iniciar la nueva ROM
|
|
ld de, $ed80 ; en $bffc para evitar que el cambio de ROM
|
|
wreg joyconf, %00010000
|
|
jr lspi
|
|
|
|
ldedg2 rst $18 ; call routine ld-edge-1 below.
|
|
jr nz, ldedg1
|
|
ret
|
|
|
|
lspi in a, ($1f)
|
|
jr lspi2
|
|
|
|
ldedg1 ld a, $16 ; a delay value of twenty two.
|
|
ldelay dec a ; decrement counter
|
|
jr nz, ldelay ; loop back to ld-delay 22 times.
|
|
lsampl inc b ; increment the time-out counter.
|
|
ret z ; return with failure when $ff passed.
|
|
in a, ($fe) ; row $7ffe. bit 6 is ear, bit 0 is space key.
|
|
xor c ; compare with initial long-term state.
|
|
and $40 ; isolate bit 5
|
|
jr z, lsampl ; back to ld-sample if no edge.
|
|
jr lcont
|
|
|
|
rst28 ld bc, zxuno_port + $100
|
|
pop hl
|
|
outi
|
|
ld b, (zxuno_port >> 8)+2
|
|
outi
|
|
jp (hl)
|
|
|
|
lspi2 wreg scandbl_ctrl, $c0 ; lo pongo a 28MHz
|
|
push de ; colisione con la siguiente instruccion
|
|
defb $fe
|
|
|
|
rst38 jp $c006
|
|
|
|
lspi3 wreg flash_cs, 1 ; desactivamos spi, enviando un 0
|
|
wreg master_mapper, 8 ; paginamos la ROM en $c000
|
|
wreg flash_cs, 0 ; activamos spi, enviando un 0
|
|
wreg flash_spi, 3 ; envio flash_spi un 3, orden de lectura
|
|
and c
|
|
out (c), h ; envia direccion 008000, a=00,e=80,a=00
|
|
out (c), e
|
|
out (c), h
|
|
add hl, sp
|
|
boot ini
|
|
inc b
|
|
cp h ; compruebo si la direccion es 0000 (final)
|
|
jr c, boot ; repito si no lo es
|
|
wreg scandbl_ctrl, 0 ; lo pongo a 3.5MHz
|
|
dec b
|
|
out (c), h ; a master_conf quiero enviar un 0 para pasar
|
|
inc b
|
|
cp %00011000 ; arriba y disparo a la vez
|
|
ld de, $bffc-67
|
|
push de
|
|
ld ixh, e
|
|
jr nbreak
|
|
|
|
nmi66 jp $c003
|
|
retn
|
|
|
|
lcont ld a, c ; fetch comparison value.
|
|
xor $47 ; switch the bits
|
|
ld c, a ; and put back in c for long-term.
|
|
out ($fe), a ; send to port to effect the change of colour.
|
|
ret ; return.
|
|
|
|
nbreak ret nz
|
|
ld de, $0051+2
|
|
call lbytes
|
|
ld ix, $c000
|
|
ld de, $4000+2
|
|
lbytes ld a, $0f ; make the border white and mic off.
|
|
out ($fe), a ; output to port.
|
|
ld c, 10
|
|
lstart rst $18 ; routine ld-edge-1
|
|
jr z, lstart ; back to ld-break with time out and no edge present on tape
|
|
xor a ; set up 8-bit outer loop counter for approx 0.45 second delay
|
|
ldwait add hl, hl
|
|
djnz ldwait ; self loop to ld-wait (for 256 times)
|
|
dec a ; decrease outer loop counter.
|
|
jr nz, ldwait ; back to ld-wait, if not zero, with zero in b.
|
|
rst $10 ; routine ld-edge-2
|
|
jr z, lstart ; back to ld-break if no edges at all.
|
|
leader ld b, $9c ; two edges must be spaced apart.
|
|
rst $10 ; routine ld-edge-2
|
|
jr z, lstart ; back to ld-break if time-out
|
|
ld a, $c6 ; two edges must be spaced apart.
|
|
cp b ; compare
|
|
jr nc, lstart ; back to ld-start if too close together for a lead-in.
|
|
inc h ; proceed to test 256 edged sample.
|
|
jr nz, leader ; back to ld-leader while more to do.
|
|
ldsync ld b, $c9 ; two edges must be spaced apart.
|
|
rst $18 ; routine ld-edge-1
|
|
jr z, lstart ; back to ld-break with time-out.
|
|
ld a, b ; fetch augmented timing value from b.
|
|
cp $d4 ; compare
|
|
jr nc, ldsync ; back to ld-sync if gap too big, that is, a normal lead-in edge gap
|
|
rst $18 ; routine ld-edge-1
|
|
jr z, binf
|
|
xor 3
|
|
ld c, a
|
|
ldloop ld (ix-2), l ; place loaded byte at memory location.
|
|
inc ix ; increment byte pointer.
|
|
dec de ; decrement length.
|
|
ld l, $01 ; initialize as %00000001
|
|
l8bits ld b, $b2 ; timing.
|
|
rst $10 ; routine ld-edge-2 increments b relative to gap between 2 edges
|
|
binf jr z, binf ; return with time-out.
|
|
ld a, $cb ; the comparison byte.
|
|
cp b ; compare to incremented value of b.
|
|
rl l ; rotate the carry bit into l.
|
|
jr nc, l8bits ; jump back to ld-8-bits
|
|
ld a, h ; fetch the running parity byte.
|
|
xor l ; include the new byte.
|
|
ld h, a ; and store back in parity register.
|
|
ld a, d ; check length of
|
|
or e ; expected bytes.
|
|
jr nz, ldloop ; back to ld-loop while there are more.
|
|
or h
|
|
bin2 jr nz, bin2
|
|
ld bc, zxuno_port + $100
|
|
ret ; return
|