Changes
:Great.
:Just to be a pain... Did you think about worst case scenarios? Like one programmer reading the keyboard immediately after the mouse/joystick input... Maybe then the raising edge could be important :-) --[[User:Nocash|Nocash]] 16:53, 9 April 2010 (UTC)
Hi Nocash, as far as I know, the inputs of the AY-8912 io port are saved in a register? Maybe I'm wrong, but this is what I was referring to as a "Latch".
Also, regarding the Com pulses, if you try the Basic examples given in the AMX handbook, the Com port is then working at it's normal speed, so the mouse reacts differently. That was another reason why it was important that the CPC was controlling sample rate on my interface.
The diode in the 74LS145 isn't specifically there to pull the signal up, it just happens to have that effect.
Yeah, worst case scenarios, I tend to be a fanatical worst case scenario tester, because if it can happen, it will happen. I dropped the voltage on the CPC to 4.5V to simulate heavy hardware load, I added all the commercial interfaces I own to check if anything could cause an incompatibility, I added series resistors to each Joystick port pin, to simulate old/dirty connections, and even did a very basic (but not very scientific) EMC/EMV test to see if I could get the processor to reset from external interference. The interface worked no matter what I threw at it. And that's what really counts.
Also on the other side of the interface, I have tested around 40 different types of mouse up to now, everything from the simplest PS/2 mouse to 12 Button multi-speed gamer mice and even a selection of wireless mice. The only one's that don't work are Bluetooth wireless mice which can't be forced into PS/2 mode, everything should work perfectly.
@ Arnoldemu: Have you built the interface? Let me know how your tests go.
