The IDE isn't very fast on the SA1100 as the cycles are fairly long. The SA1110 helps a bit (hence why the Rio Central has faster IDE than the carplayer).

Given a PXA255 like I have on my desk here, I can get more like 8mbytes/sec via PIO simply due to better timing options in the chips IO block. Even more with DMA

Ethernet can be done by the SMSC chip without many problems, but there aren't "lots of" non-PCI 100mbit chips; the SMSC one was the only one I found, last time I looked.

The best solution would likely be something like the Cirrus 9312, if it ever comes out. It has (onboard) IDE-DMA, 100mbit ethernet, USB host, etc. Again, I have one of these on my desk, but it's an old rev and was very buggy (and it's already 2 years late) - it also may not drive the VFD without some hackery.

A PXA would be nice for outright speed (400 vs 200MHz of the Cirrus), and ARM9E extensions (for audio algorithms), but you then need to add ethernet & a USB host chip.

The big issues are:

- 4-channel audio out. Use a DSP or just do it all in software with 2 stereo DACs? If you go this route, what will do the FM MPX/RDS decode as well as the DSP? Going the other way, I don't know how many software changes would be required to get the latest (ie, only available) philips DSP working.

- Software support. It's likely that we'll aim for a 2.4 kernel in 3.0, to ease things like ext3, but there's still going to be far more work involved than could get done in spare time.

- Cost. Both CPUs are BGA, so "kit form" is going to be out. It's likely to be spendy.

Hugo