S-100 Memory Card Design Input

I posted a few minutes ago on usenet in comp.os.cpm about a big fancy S-100 memory card. If anyone in here would like to add to the feature list or suggest a change, now is the time to do it. We should probably keep the discussion in one place, and its already at comp.os.cpm, so maybe reply there? Here is the text: THIS is your chance to get in any requirements. The board will have quite a few QFP and fine surface mount parts. Hardware modifications at a later date may be hard. : ) I am designing the board around MITS S-100 specifications. I do not have any other S-100 machines or experience with them. If your IMSAI or whatever has additional I/O, then please tell me if its I/O, I, O, the pin, and what it does. For example, I really have no idea how PHANTOM works. I'm not really interested in digging up the details on how these things work since the have no meaning to an Altair. The I/O question is a biggie. Timing is not an issue since that can be worked out at a later date in the CPLD. If there is an Altair signal that is only an input and you want/need it to be I/O, I would also need to know that now. The board will have a landing for 128kbyte ($2.80) or 512kbyte ($5.10) SRAM. It will also have a landing for 512k of FLASH ($4.62). The price difference between 64kx8 and 512kx8 is $2, so it hardly makes sense to choose 64kx8... Bank swapping can/will be worked out later in the CPLD code. This board MAY have a landing for a bunch of other optional functions, but for those of you who don't care about those options, you don't need to install them. For example, two 6850 type serial ports, 4x SD cards to emulate Altair disk drive systems, mp3 decoder and ethernet ; ). Another point to discuss is if its worth having an 8MByte 8 pin soic (very small, like pinkey finger nail sized) FLASH chip tied directly to the CPLD. This would allow the 8080/Z80 to access the serial flash without AVR interference. The 4 SD cards for Altair disk emulation are not available directly to the 8080. Is it also worth having a 5th SD card also directly connected to the CPLD? How many of the 8MByte data flash chips should there be? The poor things are $2.70 a piece and we could have 4-8 and hardly notice. All of the chips will be tied together with a Xylinx MAX II CPLD, and buffered to the S-100 bus with 8T97 or equivalent ICs. As you can see I am very flexible. My goal is to create a "SuperAltair" card with a lot of universal appeal. Sort of "add the chips you want and nothing more" card. Should I throw in the functionality of the GIDE while I'm at it? Let me know what you want and I'll see if I can fit it in. The entire card will be open source, except for the ROM monitor which is IP to a fellow enthusiast. I will sell the PCBs for around $35. The CPLD is $10, SRAM/FLASH as priced above, add a few $ for heat sinks and voltage regulators and you could be started for under $60. I will be soldering the crazy surface mount parts for those who are not brave enough. ; ) Grant