Daystar Power Central Control Panel question

[JDW]

I have a socketed 50MHz 68030 Daystar PowerCache accelerator in one of my SE/30's, which uses the Power Central control panel to enable caches.  In the documentation it mentions that Enhanced Power Math can be enabled by holding down the OPTION & COMMAND keys while clicking the PowerMath switch in the control panel.  I confirmed this works because that results in an underline beneath PowerMath.  (Enhanced PowerMath makes FPU performance even better.)  Being curious, I held down OPT & CMD while clicking the PowerCache switch in the same control panel.  This is not documented in the manual. A little black dot appears in the bottom left corner when you do that, as marked by the arrow cursor in the following screenshot:



My question is, what does that little black dot in the bottom left corner of the Power Central control panel signify?

Thanks.

 

[JDW]

Six days later and not a single reply.  Well I will reply to myself then...  :rambo:

I rand Speedometer benchmarks with and without the little dot, and with the dot all tests are slower than without the dot (even FPU performance).  It's almost like it disables some caching, but the question is what caching?  Doesn't make any sense that it would be all the caching, seeing there are two switches in the control panel for that. Hmmm...

 

[Brooklyn]

4+ years and I’ve got your first reply! I was able to get an early P30 IIci Powercache working with Bolle’s adapter on an SE/30 using this hidden option. Without it, the computer instantly locks up when enabling the cache.

Maybe it’s some sort of compatibility mode?

 

[Phipli]

4+ years and I’ve got your first reply! I was able to get an early P30 IIci Powercache working with Bolle’s adapter on an SE/30 using this hidden option. Without it, the computer instantly locks up when enabling the cache.

Maybe it’s some sort of compatibility mode?

Its a test mode for troubleshooting cache issues most likely.

It disables the external cache on the board. (But not the CPU cache).

I... did actually reply to this but it was lost in The Great Server Crash.

 

[Brooklyn]

Interesting, although after using this method to “turn on” power cache, power demo reports the external cache is enabled:

 

[ymk]

The cache control register might reveal something.

Dropping into Macsbug and typing CACR will show the contents.