<div dir="ltr"><div dir="ltr">Well, there is an additional gate array chip on the 256s(I believe every variant), so it's possible that the U60 simply doesn't know how to work it. I have a hunch the U30s are in the same boat.<div><br></div><div>As far as a way to hack the OBP to enable or add functionality to the memory controller, I'd imagine it's possible, but that's way out of my league. Though I wish I could meaningfully contribute. </div><div><br></div></div>-mark<div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Sat, May 7, 2022 at 2:11 PM Chris Quayle <<a href="mailto:syseng@gfsys.co.uk">syseng@gfsys.co.uk</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><br>
><br>
> Today's Topics:<br>
><br>
> 1. Re: Sun Ultra 60> 2 Gb Memory ? (Ethan Hawke)<br>
><br>
><br>
> ----------------------------------------------------------------------<br>
><br>
> Message: 1<br>
> Date: Sat, 7 May 2022 13:11:02 +1000<br>
> From: Ethan Hawke<ehawk@ember.systems><br>
> To: <a href="mailto:rescue@sunhelp.org" target="_blank">rescue@sunhelp.org</a><br>
> Subject: Re: [rescue] Sun Ultra 60> 2 Gb Memory ?<br>
> Message-ID:<1adcbcd9-6b24-fb4c-0834-a79f5ebc42be@ember.systems><br>
> Content-Type: text/plain; charset="utf-8"; Format="flowed"<br>
><br>
> The DSC (Memory Controller in the U2) can only address up to 2GB of<br>
> total memory, I would guess that 256MB SIMMs would be treated as 128MB<br>
> as the extra addressing pins would probably be grounded.<br>
><br>
> Cheers,<br>
> Ethan<br>
<br>
<br>
><br>
> On 5/7/22 04:22, Mark M wrote:<br>
>> There were 256MB Dimms of that type (200pin), but were only ever<br>
>> certified for U80 and E450s.<br>
>><br>
>> The handbook memory compatibility matrix actually notes that they do<br>
>> work in e60s but there's an obp bank limit of .5G.<br>
>><br>
>> All that said, I've never tried, but would, if my machines weren't in<br>
>> storage at the moment.<br>
>><br>
>> -mark<br>
>><br>
<br>
Thanks for the replies. If you think that 2Gb is a signed 32 bit number,<br>
the 2Gb limit would make sense, but if 256 works in a U80, I wonder if<br>
the obp firmware could be hacked to allow more than 0.5Gb per bank ?.<br>
Don't have a U80, but it follows on from the U60, perhaps just an<br>
upgrade ?. Ideal would be if the MB is the same ohysical size, but not<br>
exactly thick on the ground.<br>
<br>
May just buy 4 x 256 dimms to see what obp thinks it's looking at...<br>
<br>
Chris<br>
<br>
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</blockquote></div></div></div>