Subject: Re: NetBSD on DECsystem 5500
To: Jonathan Stone <>
From: Simon Burge <>
List: port-pmax
Date: 12/18/1996 11:59:19
On Tue, 17 Dec 1996 15:18:53 -0800  Jonathan Stone wrote:

> The 5500s (mipsfair II) are a hard target.  They have an undocumented
> 'intelligent' ethernet interface, DSSI, etc..
> The 5400s would be easy in comparison.  IIRC, the 5400s have the same
> motherboard devices (chips)  as the Mayfair series microvax3s.
> NetBSD/vax contains all the relevant Qbus adaptor and Qbus device
> support. You'd have to glue in the vax-derived  rtc code,  and use
> the appropriate technique to drain the CPU write-buffers.
> If the PROM interface is the same, this comes down to judicious
> cut-and-paste and debugging.
> In contrast, a port to the 5500s requires dealing with obsolete,
> undocumented,  DEC chips, or ignoring them and substituting equivalent
> Q-bus devices and drivers.  It would really be much easier if those
> were debuggged on a 5400 first.
> still, if someone   wants to either try, or donate a mipsfair....

Hmm, didn't realise it was this bad.  I guess the 20 or so 5500's we
have around here will just fade away...  (And we don't have any

I guess we're talking about some of the slower mips boxes (along with
2100/3100's).  And to think, we paid about $AUS250k per 5500 a few
years ago :-(