LCIII PowerCache Adapter - LCIII PDS Spelunking

[Trash80toHP_Mini]

Interesting tangent popped up concerning a TP post about alleleration options for the LCIII:

https://68kmla.org/bb/index.php?threads/wtb-accelerator-card-for-lc-iii.38988/post-421488

Passive LCIII PowerCache Adapter:



There you go @Bolle what can you see?

 

[Trash80toHP_Mini]

LC PowerCache Adapter for comparison:

 

[Trash80toHP_Mini]

Accidentally ran across the remains of my third adapter. Fumble fingered attempts to remove the connectors for reuse fail yields destructive removal of same for PCB examination. Looks like four layers of traces, P&G?

 

[olePigeon]

Looks like the LC PowerCache adapter has actual chips on it that would need to be copied. The LC III PowerCache adapter looks like a simple pass-through with a handful of caps and resistors.

So is the LC III PDS slot smarter? Works as standard II-style PDS as well as LC PDS compatible?

 

[Trash80toHP_Mini]

From the TP Tangent linked above:

IIRC LCIII adapter for PowerCache is passive, plugging into its 32bit extended slot. Not sure how that works now that I think of it, very curious that! I bought several just for the connectors in the Shreve Systems blowout sale way back when.

The active components on the adapter above probably neck the full blown IIci Cache Slot PowerCache to the short shrifted CC/LC PDS. Note the differenc in length of the two connectors.

That makes sense since IIRC the LCIII is a cut down IIci or very similar.

So it looks like it's time to dive into the LC, LCIII and IIci DevNotes.

Mac II & IIcx adapters for PowerCache plugged into CPU & PMMU sockets to convert those interfaces to IIci Cache Slot. It would appear that the LCIII PDS amounts to a jumbled IIci Cache slot. That, or it amounts to a full 68030 pinout/interface as on the Socketed PowerCache for the SE/30.

Both are pretty much the same thing, but jumbled every which way when it comes to the connector pinouts.

Delta notes on the short shrift 68020 LC PDS vs. full blown 32bit 68030 LCIII PDS will be most interesting.