On Fri, 17 Jul 1998, Kari Lammassaari wrote:
> The MSX side demanded MC-code (msx-interrupt routine resets the joystic
> bits of PSG ) , but PC could do it with Pascal.
>
You did an asm routine just because the interrupts were messing
the communication? Remember you can disable interrupts from BASIC using
the command:
VDP(1)=VDP(1)AND223
But I don't know if BASIC can be fast enough to mantain a fast
connection...
BTW, I tried yesterday to make a joystick connection but I
couldn't set the joystick as an output. I discovered the joystick port
works this way:
1 2 3 4 5 1=UP 2=DOWN 3=LEFT 4=RIGHT 5=VCC
6 7 8 9 6=B1 7=B2 8=GND 9=UNKNOWN
The MSX Red Book says some pins are TTL open-collector outputs. I
thought the output was pin 9, so I wired a pull-up of 470R, and then
wrote:
10 VDP(1)=VDP(1)AND223
20 OUT&HA0,15:OUT&HA1,&HFF:REM ALSO TRIED &HA1,0
... and got no result. So I guess I tried the wrong pin. Which pin
is used to make output? Also, how much current can I drain from this pin?
Can I connect a 10mA load without needing a driver?
------------------------------------------------------------
Ricardo Bittencourt http://www.lsi.usp.br/~ricardo
[EMAIL PROTECTED] "Save the trees: eat more woodpeckers"
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