Logic Board - Macintosh Classic Reloaded

[TheOneWhoIsMany]

Hi There,

I've had some boards made, but unfortunately, my Classic donor boards SND and RTC chips are destroyed.

Kai's post mentions that "Macintosh II, IIx, IIfx, IIcx, IIci, and IIsi all use the same SND and RTC chips." I happen to have an IIsi board to source SND and RTC chips from. Does anyone happen to know which chips are the correct ones?

• I think the IIsi has two sound chips at UB7 and UB8. Is that correct?
• I can't figure out which chip is the RTC, can anyone point me in the right direction?

Cheers

 

[Kai Robinson]

The SND chips are indeed the same on the Iisi, however the Iisi is the first machine that used the EGRET for RTC and ADB instead of discrete chips so there is no RTC for you to salvage off that board, unfortunately.

 

[TheOneWhoIsMany]

Thanks Kai, damn.

Well my question continues for an RTC chip

 

[lilliputian]

The RTC was successfully reverse-engineered not so long ago, so you may be able to get one afterall if you can't find a donor.

 

[TheOneWhoIsMany]

The RTC was successfully reverse-engineered not so long ago, so you may be able to get one afterall if you can't find a donor.

I've done some searching and found this project and found the one you are talking about. I've never programmed an ATTiny85 before so going to be a bit of a learning curve there.

Thanks for suggesting it.