Features that really should be a part of the A3000 by Dave Haynie [0] CPU, etc. 68020 at 14.2 MHz, 68881, Welland MMU/Cache chip set. That's the obvious part of the system. [1] Hi Density Floppy Disks Apple and IBM already have 2 Meg 3.5" disks (though IBM screwed up by not supporting 2 Meg ID keying), so it's only Atari and us left. We don't want to be the last guys on the block, now, do we? This would of course require a new Paula design. Or an expensive external control chip. [2] On board SCSI Another desirable feature. Apple's got this as standard on all their machines. Maybe this could be fit into a Fat Paula, but if now, a cheap Boyer SCSI chip might be OK, though we're going to be seriously pressed for space. [3] RAM Need lots of this. Chip memory should be 1 meg minimum, expandable to 2 megs minimum. Fast memory should be super FAST at 14.2 MHz, a meg at $C00000 sounds good. Gotta refresh this one somehow. [4] Video AgnusHR and DeniseHR fer sher. That gives up 640x512 standard in for grey tones, providing you want to kill CPU throughput whenever you're talking to CHIP RAM. Not exactly my idea of a high performance system. If we can't teach a Fat Denise to read 32 bits at a time, maybe an external Denise prefetch buffer could do the same thing. Anyway, something like this should be in order. [5] Expansion Memory Stuff The Expansion bus is extended to 32 bits of address, 32 bits of data. There should be at least 3 32 bit slots and 2 16 bit slots (the latter overlaps with the PC bus stuff, if we keep it). The elimination of the CPU slot might allow for a 4th 32 bit slot, if the space isn't needed for chips. The auto-configure system is extended to identify new features of a board. A board may run at 14.2 MHz (this feature can be used by the expansion memory allotment schemes to give preference to fast memory). A board may run 32 bits wide, and the system treats this knowledge similarly. A board may exist above the 16 Meg 68000 space; this is used by the expansion board allotment routines. Plenty of room in the Autoconfig ROM for this. Also, the additional interrupt channels available should be noted. Welland's nybble mode architecture should be considered here at least as an option. [6] Expansion DMA Stuff New DMA modes for 32 bit devices should be considered. First of all is an interleaved DMA option. A board can request access to the expansion bus when the 68020 isn't using it. This can speed throughput, since the 68020 never has to slow down to let hard disk or other DMAs occur, unless the two are contending for the same memory. At this point, a DMA device could be considered a higher or lower priority than the main processor. Along with this goes the second possible enhancement, which is cycle-by-cycle DMA arbitration. Instead of forcing a slowdown while the bus is arbitrated 68000 style, a fast arbitration on memory cycle boundaries takes place. Finally, the third enhancement is that any DMA device is succeptable to DMA by another, thus eliminating the need for a CPU slot. Perhaps a DMA device can assert itself as either "HOST" or "DEVICE", where hosts can be pre-empted by "DEVICES", but where "DEVICES" don't stay on long. This could be extended to a multi-level DMA priotitization, the main CPU being somewhere in the middle.