Apple II 3-voice synthesizer card - clone of the 1st gen ALF Apple Music Synthesizer
Here is a list of chips on the "clone card" documentation, which I assume are also in the 3-voice ALF card.
Square-wave chiptune goodness, but it's good for 8 octaves of tuning range, vs. 6 octaves for the later card.
1 - 74LS624 - voltage controlled oscillator
1 - 8253 (programmable timer - Intel support chip common in old IBM PCs)
1 - 74LS32 - Quad 2 Input OR Gate
1 - 74LS04 - Hex Inverter
2 - 74LS75 - 4 Bit Bi-Stable Latch
4 - CD4723B - Dual 4 Bit Addressable Latch
3 - 8227DP - ??? unknown chip There is a contemporary Audio Amp chip, but that one will not fit in a DIP socket.
1 - LM307 - op-amp
I apologize for the image quality, and would appreciate it if someone would take a photo of the front and back of their
original 3-voice ALF card (there is one here at the Computer History Museum, but the photo doesn't show enough detail. I'm particularly looking for more data on the 8227 chips used on the right hand side.