Good afternoon folks!
Does anyone have...
1. An LC family Macintosh like the LC 475 or older...
2. An Apple II LC PDS card
3. An oscilloscope
4. Some spare time!
I'm curious to find out about the electrical characteristics of the audio output from the card. It comes out of the card on Pin A1, right in the corner. The following is an ethernet card, but shows the pin in question on the underside. If you're looking from above, on the solder side, it would be in the far back left of a Pizzabox LC.
If you could let me see an image of the waveform shape when the IIe card is playing audio, and give me an idea of what the max and minimum voltages are?
My expectation is that it is some kind of PWM or PCM sound, between 0 and 5v, but I'm curious to know, as I'd like to re-use that pin to inject audio into an LC for other purposes.
The LC Dev Note says the following :
Cheers!
Does anyone have...
1. An LC family Macintosh like the LC 475 or older...
2. An Apple II LC PDS card
3. An oscilloscope
4. Some spare time!
I'm curious to find out about the electrical characteristics of the audio output from the card. It comes out of the card on Pin A1, right in the corner. The following is an ethernet card, but shows the pin in question on the underside. If you're looking from above, on the solder side, it would be in the far back left of a Pizzabox LC.
If you could let me see an image of the waveform shape when the IIe card is playing audio, and give me an idea of what the max and minimum voltages are?
My expectation is that it is some kind of PWM or PCM sound, between 0 and 5v, but I'm curious to know, as I'd like to re-use that pin to inject audio into an LC for other purposes.
The LC Dev Note says the following :
Cheers!