Thread
II SI?
Definitely worth grabbing that IIsi! Any old Mac like that should be saved in my opinion.
That's nothing, I know a guy who managed to transport a Superbrain home on his bicycle. Just take plenty of bungees and make sure the base unit and monitor are well fastened to the luggage rack / panniers.
the two nubus slot adapter sounds suspect to me 
of what use would be a nubus card where you cant access teh back panel...
the adapters with two slots are either dual PDS adapters so you can plug in two PDS cards (one accelerator and a nic for example) or they are nubus+pds adapters.
of what use would be a nubus card where you cant access teh back panel...
the adapters with two slots are either dual PDS adapters so you can plug in two PDS cards (one accelerator and a nic for example) or they are nubus+pds adapters.
http://cgi.ebay.com/Apple-820-0305-01-Mac-IIsi-NuBus-Adapter-Card_W0QQitemZ170200781142
here is the PDS to Nubus adapter for the IIsi
here is the PDS to Nubus adapter for the IIsi
A few other thoughts. As is commonly known, the oscillator on the IIsi can be replaced and the machine clocked up to at least 25 MHz. Some have taken it to 27 or 28 MHz. A few MHz may not sound like much, but at those overall speeds, each MHz is a substantial percentage of the total.
The NuBus adapter could probably support multiple slots, but it would require major modifications. Once you have the NuBus circuitry at all, most of the work is done. The modifications would be to actually get the additional connectors wired to the board, and to wire the slot ID pins properly, adn finally to identify some additional unique interrupt lines to connect the slots' interrupt to--one interrupt per slot. I imagine the chipset has the interrupts available on some of the pins, since the chips are probably the same or very similar to those used in the IIci.
It would be interesting to try wiring larger memory capacity into the built-in 1 MB bank of memory. Again, given the simiilarities to the IIci, it should be able to take 64 MB in that bank.
But then, once you've gone to all the trouble above, you'd just have a IIci, so really, I guess it's kind of silly.
The NuBus adapter could probably support multiple slots, but it would require major modifications. Once you have the NuBus circuitry at all, most of the work is done. The modifications would be to actually get the additional connectors wired to the board, and to wire the slot ID pins properly, adn finally to identify some additional unique interrupt lines to connect the slots' interrupt to--one interrupt per slot. I imagine the chipset has the interrupts available on some of the pins, since the chips are probably the same or very similar to those used in the IIci.
It would be interesting to try wiring larger memory capacity into the built-in 1 MB bank of memory. Again, given the simiilarities to the IIci, it should be able to take 64 MB in that bank.
But then, once you've gone to all the trouble above, you'd just have a IIci, so really, I guess it's kind of silly.
IIsis are nice machines; it was actually my first 68K Mac. If you install the RAM Muncher INIT and keep an eye on your extensions, the performance isn't too bad. I haven't used mine much since I got my Quadra, but they're not bad at all, especially for free. The floppy port is a nice bonus, too.
I've got a 2-NuBus dealie in one of my IIsis. It came with a fairly expansive SuperMac video setup. The two cards fit because they partially overlap, with the (custom-made) bottom card's port protruding through the top card's back slot cover.
I doubt it would be easy to install two normal NuBus cards in the thing, unless the bottom card didn't need external connectivity.
I doubt it would be easy to install two normal NuBus cards in the thing, unless the bottom card didn't need external connectivity.