Ideas now that the information is available: The Cache connector has only a few address lines available, limiting the ammount of cache memory that can be used by the accelerator. With the CPU passthru connector, you could build a small board with >32k cache. You could put 1 megabyte or more on the card! I don't know if the board would still function due to the overhead of keeping track of the cache. I also don't know how the cache connector is connected to the CPU. I think it may go through some of the other chips on the board, and I don't know what they do yet. Other ideas: How about modifying a Focus hard disk controller to plug directly into the CPU passthru connector? I am pretty sure all you would need is an address decoder so that the focus would intercept any data meant for it. Advantages of doing this? I don't know because I am still learning how the TWGS operates. It seems that you would be able to access the focus at 1Mhz bus speed, without the overhead of sending commands to the drive at 1Mhz. I don't know what kind of speed improvement you would get.
How about ripping all the chips off an old IIgs or IIe, and creating an interface between the TWGS CPU passthru and the slots in the seperate II? You could access the slots at greater than 1 Mhz. Advantages? I don't know, will any cards run at greater than 1Mhz? It seems like some do. The transwarp IIe speeds up access to some interface cards. There are dip switches to slow down data going to each slot (seperately) if you choose to. Now somebody may say that it would be a tough thing to do because the 1Mhz is tightly related to the system and video clocks (they use the same crystal). Answer: rip all the video and clock circuits off the board and I think all you need to access the slots is a decoder to see which address is being accessed by the CPU. I guess you'd need to add a new clock for the slot access to synch to the CPU timing too. Hmm. What would this get you? I don't know. I don't have any cards that I'd really like to go faster. You could have more than 7 slots in your GS :). You could either create a system that would switch the CPU's acces to slots between the main GS mother board and the CPUpassTHRU slots, or create a special driver that uses unused/rarely used I/O locations in the c100-c700 memory space, and use all 14 cards at once. It would probably be too specialized for a particular system if they were mapped to different i/o locations though.
One more quick idea while I am here updating the page. How about an ethernet adaptor that attaches to the CPUPASSTHRU? I think one of the main problems with creating an Ethernet card for the GS is BUS speed. The TWGS could download all of the ethernet data into a Cache, and then send it to the GS at 1mhz. The TWGS could take care of all the ethernet commands and protocols. Just an idea, I have no desire for ethernet whatsoever.
Have any ideas for the use of the CPU passthru? Let me know!