There are two 21140 based DE500 "DEC Fast EtherWorks" interfaces: the 
DE500-XA and the DE500-AA. The "FCC ID" silkscreened on the PCB will 
tell you what you have (so will NetBSD autoconfig output at boot 
time):

	DE500X = XA (21140)
	DE500A = AA (21140)
	DE500B = BA (21143)

In my experience, SRM has issues with the XA; I don't believe that 
model supports Nway (IEEE 802.3u) negotiation.

I've only managed to successfully netboot Alphas with the DE500-AA in 
them. The DE500-AA works fine doing Nway with my old Dlink DSS-8+ 
10/100 switch, and with the Netgear FS108 and FS524.

Just FYI, there also the DE500-BA, which is based on the 21143. It 
has Nway support, but there are some quirks with its PHYs. SRM 
negotiates with Nway properly (i.e. the FDX lights up on the switch), 
but NetBSD is spotty. Just after boot, when the interface is 
configured, the switch shows 100Mb/s, but not FDX even though I use 
"auto" in the ifconfig statement.

However, if I then manually:

	ifconfig tlp0 media 100baseTX-FDX
	ifconfig tlp0 media auto

The NIC will renegotiate, and the switch will show 100Mb/s *with* FDX 
on. Also, the DE500-BA showed up late in the Alpha workstation 
product lifetime and because of this, early versions of SRM don't 
support it - if you want to try and netboot with it, you should use 
the latest version of SRM for whatever Alpha you have.

DEC DE500-AA PCI ethernet interfaces show up on eBay from time to 
time; they tend to go for anything between $5/ea and $20/ea plus 
shipping.

Hmm. I should send-pr this, I guess.

	Erik <fair@clock.org>