Hi all,
I have a Mockingboard clone from Capital Computer Co called a Super Mocking Board. It has a number of neat features - one of which I'm puzzled by.
Namely, it has dual 5-bit binary weighted DAC's wired to one of the AY-3-8910 programmable sound generator IO ports - 5 bits for each audio channel (L/R). This is implemented with 4k7/10k/20k/39k/82k resistors on IO pins IOB7..3 and IOA7..3 on just one of the AY-3-8910. The other AY-3-8910 has nothing connected to any of the IO pins. It makes me feel they had a another use for this card beyond the Mockingboard functionality.
Of course this would require specialist software to use the IO ports on the AY-3-8910 and I'm curious if anyone knows anything more about the card, or has the software?
Cheers,
Dean
Can you supply a few images of this card?
Here is a picture of the card from the Apple II Peripherals Photo Library Flipbook #4 (https://fliphtml5.com/tuvuy/zvox/Apple_II_Peripherals_Photo_Library_Flipbook_%234/)
super mockingboard.png
The DAC resistors can be seen on the left side of the card. In the interest of future projects I've fully reverse engineered this card and I found that particular feature intereresting, along with a couple of other interesting things - the main one being that it only uses a single 6522 VIA, but another in that it reproduces the speaker beep onboard, with no connection to the motherboard speaker output.
I'm mostly curious about the DAC though - software would have to be written to use the IO ports on the AY-3-8910 ICs (those are the 2 40 pin packages on the left, with the VIA being the rightmost 40 pin package). Most of the logic chips are there to reproduce the speaker click with access to $c03x. So little software was written to support Mockingboard back in the day, and I imagine even less to support this DAC!
This appears to be a super-sized version of the "Mustalgame" Card also made by Capital Computer Co (based in Hong Kong). There is a manual here:-https://mirrors.apple2.org.za/Apple%20II%20Documentation%20Project/...
Photos:-https://mirrors.apple2.org.za/Apple%20II%20Documentation%20Project/Interface%20Cards/Audio/...
I tested one before, and managed to hear Apple speaker sound, and some Mockingboard sound effects, but not music. I suspect a defect on the card. Here it is working, somewhat, with BERZAP:
Berzap with Mustalgame Card on Apple II clone 720p.mp4