Registered DIMMS on Blade 100

I noticed that the Sun Systems Handbook for the Sun Blade 100 lists a
jumper, JP6, as having the function of enabling or disabling
registered DIMMs. The default factory setting is to disable
registered DIMMs, and experience has shown me that registered DIMMS
definitely do not work in Blade 100s (or 150s) by default (makes
sense). However, the systems handbook also says that the memory
controller is on the IIe/IIi processor itself, and I know that IIi
processors such as the one in the Fire v100 take registered DIMMs, so
it seems plausible to me that Blade 100s, jumpered with this JP6
jumper, should be able to take registered memory.

However, I tried shorting this jumper, installing registered PC133
(from a Fire v100 in fact) and the system didn't want to boot
properly. Has anyone successfully used registered RAM in a Blade
100? The Blade 100 printed documentation makes absolutely no mention
of this jumper, so I'm not sure if it is supposed to work or not, or
if my dimms are bad, or if the OS this Blade 100 is running is
malfunctioning and preventing bootup.

I don't have a console to plug into this machine right now, but I was
wondering if anyone could offer any insight.

Thanks

glenn k. lockwood

On Jul 10, 11:04*pm, glennklockwood <glennklockw...@gmail.com> wrote:
> I noticed that the Sun Systems Handbook for the Sun Blade 100 lists a
> jumper, JP6, as having the function of enabling or disabling
> registered DIMMs. *The default factory setting is to disable
> registered DIMMs, and experience has shown me that registered DIMMS
> definitely do not work in Blade 100s (or 150s) by default (makes
> sense). *However, the systems handbook also says that the memory
> controller is on the IIe/IIi processor itself, and I know that IIi
> processors such as the one in the Fire v100 take registered DIMMs, so
> it seems plausible to me that Blade 100s, jumpered with this JP6
> jumper, should be able to take registered memory.
>
> However, I tried shorting this jumper, installing registered PC133
> (from a Fire v100 in fact) and the system didn't want to boot
> properly. *Has anyone successfully used registered RAM in a Blade
> 100? *The Blade 100 printed documentation makes absolutely no mention
> of this jumper, so I'm not sure if it is supposed to work or not, or
> if my dimms are bad, or if the OS this Blade 100 is running is
> malfunctioning and preventing bootup.
>
> I don't have a console to plug into this machine right now, but I was
> wondering if anyone could offer any insight.
>
> Thanks
>
> glenn k. lockwood

Just as an update, this jumper does in fact work. If you short out
the JP6 jumper (between the edge of the motherboard and the DIMM0
bank), the system will operate with registered ECC RAM.

The problems I was having were not related.