Re: NetBSD on Q-bus MIPS?

["Maciej W. Rozycki" <macro%linux-mips.org@localhost>]

Hi Jonathan,

> [ cC'ed to port-vax for Qbus/enlcousure questions.  Please reply via 
> email, or a single mailiing list, where not of interest to the list 
> membership(s)]

 Sending everywhere as information included here applies to various DEC 
hardware and I think it might be useful to someone.

> Recent removal of NetBSD FDDI drivers prompted me to look at FDDI 
> support.  I just acquired a R4400 (decsystem 5900, and Q-bus boards for 
> the 5400 (KN01) and 5500 (KN220).  The DEC "PDQ" interfaces are the 

 The 5400 is KN210 AFAIK; KN01 is the 2100/3100 aka PMIN/PMAX.  Confusion?

> fastest available for Turbochannel or Q-bus machines.  I bought a 
> handful on eBay and I hope to revive the FDDI driver and make it 
> MP-safe.

 FYI, I am not allowed to share hw documentation on the PDQ/PFI I have 
obtained from HP back in 1994, but please feel free to ask questions if 
existing code out there does not answer them.  For Q-bus the host bus 
bandwidth will limit the performance of the PDQ I'm afraid.

> I started contemplating going down this route as a way to fuzz-test 
> binaries (esp. Ultrix/mips binaries).
> 
> It's 30 years since I last configured a Q-bus. I already have PDF copies 
> of the Technical Reference Manual for the KN01 and the KN220 boards.  
> I'd appreciate any help or pointers or risks in configuring these 
> systems in a BA123 "World Box'; or finding a BA213 enclosure with 
> motherboard and the dual-height slot outside the CPU slot, for the DSSI 
> distribution "paddle board".

 Why not the BA430 (also used with the VAX 4000-200)?  At least as an 
option to consider.  It seems more robust, although its H7874 PSU has 
capacitors that suffer from the dreaded issue with the quaternary ammonium 
salt system causing the seal to fail and leak, and therefore require them 
to be replaced ASAP; unfortunately the mechanical design of the PSU makes 
some of these caps difficult to replace.  But then the BA123 or BA213 PSU 
may have this issue too (I don't know).

 AFAIK you'd normally end up with the KN220 in a BA123 only as a field 
upgrade from the KN210; the KN220 itself came in either a BA213 or a BA430 
enclosure if ordered new.

 For the KN220 you may find two documents useful, both available online:

- "DECsystem 5500 Technical Manual", Order Number EK-D5500-TM-001,

- "KN220 CPU System Maintenance", Order Number EK-375AA-SM-001.

Let me know if you have troubles tracking them down (I gather your 
technical reference is the former).  There's some more documentation 
available regarding the BA430 (and the BA213) too, as well as user-level 
KN220 manuals, but you probably know that already (and I don't have all 
the titles at hand).

 NB, to make the KN220 work you'll need the CPU module, the I/O module, 
the CPU I/O panel (same as with VAX 4000-200), at least one MS220 memory 
module, and of course all the associated cables (including the bulkhead 
SCSI connector panel).  IIUC you have already collected all these pieces, 
right?  The second manual above will have all the details.

 I have no first-hand experience with the KN210.

> There is a KA660 cab kit for the BA123, which should work with the KN220 
> (excluding DSSI).
> 
> Does anyone have experience with that?

 No idea as no experience with the BA123 here.

 DSSI is supposed to work with the KN220.  The BA430 backplane accepts 
both SCSI and DSSI devices; the DSSI bus is wired directly from the I/O 
board via the edge connector, while SCSI requires a short jumper cable 
(BC06P-2F aka 17-02659-03) from the bulkhead.

 External storage expansion boxes are of course supported as well for both 
storage systems via the respective bulkhead connectors.

 The 5900 is HUGE!

  Maciej