30 Jun
2012
30 Jun
'12
8:11 p.m.
On 6/30/12 6:49 PM, David Riley wrote:
I'm given to understand that the internal chips
weren't always even all that well documented; I have a document dump on the SWIM 2 and
3 chips that in places are little more than scrawled notes. Al may have some insight.
The four ASICs in the first generation PPC was the HMC which handles DRAM and Cache, AMIC,
which interfaces to the I/O devices, two data
path parts which also generates cycle stealing video, and the optional NuBus controller,
which isn't on the 6100. There are several 8k
sound buffers in AMIC which are serially clocked to AWACS (pn 343S0140), which is the
sound codec chip.
It was also the first 16 bit sound part Apple used. AWACS was made by Crystal
Semiconductor.
Bit clock is pin 42, sync is pin 43 and data in is pin 44. Headphone out L,R,Common pins
27,25,28 Speaker out L,R,Common pins 29,31,30