I have some doubts about joypad handles, due to
controversial points I found in the various docs:
1. Reading from $4016/$4017 when a button is pressed,
returns 1 or $41? (and when is released, 0 ro $40?)
2. $4016: After the 16 bytes from joypad#1 and joypad#3,
how many bytes for signature in the last 8 bytes?
(some docs tells 4, followed
by 4 zero bytes, other docs tell all the eight bytes)
3. Seems that when four score is not present or not switched
to 4 players, output is different (joypad#3 bytes returns
0, and signature is 0, or $ff, but what it should returns
exactly?)
4. Older documents tells that when the joypad is in
half strobe state returns data from expansion port.
From posts on this forum I know this is not true
(it returns the state of A button, because no shift
occurs). But, then, how data are read from expansion port?
Thanks,
tano
controversial points I found in the various docs:
1. Reading from $4016/$4017 when a button is pressed,
returns 1 or $41? (and when is released, 0 ro $40?)
2. $4016: After the 16 bytes from joypad#1 and joypad#3,
how many bytes for signature in the last 8 bytes?
(some docs tells 4, followed
by 4 zero bytes, other docs tell all the eight bytes)
3. Seems that when four score is not present or not switched
to 4 players, output is different (joypad#3 bytes returns
0, and signature is 0, or $ff, but what it should returns
exactly?)
4. Older documents tells that when the joypad is in
half strobe state returns data from expansion port.
From posts on this forum I know this is not true
(it returns the state of A button, because no shift
occurs). But, then, how data are read from expansion port?
Thanks,
tano