Carrera040 in Daystar adapter?

[AlpineRaven]

Evening all, 

I have MicroMac's Carrera040 CPU card and thought would Daystar Nubus adapter/pass through would work in Macintosh IIsi for the Carrera040 to work - would that work?

 

I don't have MicroMac's actual adapter (the seller lost it) but I have the CPU and I would like to use it in Macintosh IIsi.

Cheers

AP

[jessenator]

Are the cards wired the same?

 

My gut reaction would be if they're not compatible with the Twinspark, they're probably not compatible with the Daystar adapter. But I'd lean on the more savvy members for their say.

 

[jessenator]

Might be some useful stuff in there?

 

 

 

[omidimo]

Generally cache cards (Daystar, Carrera, etc) all need CACHE-slot adapters, that is clearly marked cache (and in some later adapters are marked accelerator). Any other type of slot adapter (nubus/pds) would be bad, very bad. (The term cache is confusing, but that applies to all upgrade cards including the cache-only ones.)

 

You could use any adapter that had a proper cache slot with any cache card, for example a Daystar card in a MicroMac adapter, or a Sonnet Card in a TwinSpark. I have used a few interchangeably with no issues. 

 

The only exception was the Turbo 601 that needed a special IIsi only adapter that  iirc had a single cache slot. 

Edited April 13, 2019 by omidimo

[Bolle]

Carrera 040 won’t work in a Twinspark adapter. It might work in a Daystar adapter but I would have to check that again. /BR, /BG and /BGACK are wired differently on Daystar, Twinspark and Micromac/Sonnet/Mobius adapters.

 

The Daystar 040 can do it’s job without an onboard 030, all the other 040 accelerators need a 030 to work. The Twinspark disables the onboard 030 by just pulling /BR to ground.

The Daystar adapter activates /BR once the accelerator sends the CPUDIS signal that normally is only present on the IIci cache slot and tells the host machine that another CPU takes over the bus without any further negotiation.

 

Guess I’ll give it a try and see what happens with the Daystar adapter and Micromac 040 combination. If the Micromac sends CPUDIS as well it might work. If not you could still modify a Daystar adapter.

[omidimo]

@Bolle is the man to know! Thanks for the clarification.

[Von]

1 hour ago, Bolle said:

Guess I’ll give it a try and see what happens with the Daystar adapter and Micromac 040 combination. If the Micromac sends CPUDIS as well it might work. If not you could still modify a Daystar adapter.

I am interested to see if this works. I'd give this a try however my IIsi board is dead at the moment );

 

[Von]

Did anyone try a Carrera 040 in a Daystar adapter to see if it works? I now have a working IIsi and the needed pieces however I am somewhat concerned about possible damage...

[Bolle]

Try it, it shouldn’t damage anything even if it doesnt work.

What Daystar adapter you got exactly? The Carrera won’t work on most of them.

I rewired one of my SE/30 adapters to work with the Carrera in the IIsi. The stock adapter (which implements the Daystar IIsi signal routing) wouldn’t work.

Edited December 23, 2019 by Bolle

[Von]

These are the 2 IIsi Daystar adaptors that I have.  Also have the Daystar that allows you to put an accelerator or cache card in the SE/30.