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#1 2015-06-16 23:27:45

bbraun
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Registered: 2014-05-29
Posts: 1,064
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A/UX and the djmemc 128MB SIMM support

Rather than continuing to hijack mcdermd's buy/sell thread, I figured I'd make a separate thread here.
Since CHC is using A/UX on the Q800, I tried out my ROM modification for 128MB RAM SIMM support with A/UX and a Centris 650.

An unmodified C650 will recognize 128MB SIMMs as 64MB (and take a loooong time to test the ram on boot) for a total of 264MB (64MB*4 + 8MB onboard).  A/UX seems fine with that.
With the modified ROM and 4x128MB RAM, the system will give chimes of death unless a (large) RAM disk is configured due to a problem with the memory manager handling that much RAM.
I configured the machine for 90-someodd% RAM disk, and then tried booting into A/UX.  A/UX failed to boot with an error that 90 (missing units or %) memory was used by the system, and maybe I should tune NBUF in kconfig.  I haven't tried changing kconfig, but I kind of doubt that's the issue.  It seems more like it just has a problem with that much RAM.

But, removing one of the SIMMs and booting with 392MB (128MB*3 + 8MB onboard) worked just fine.  The last 128MB is non-interleaved, but oh well.  Another 64MB or 32MB SIMM in there would probably work too.

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#2 2015-06-17 02:07:07

ClassicHasClass
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From: Electron Alley
Registered: 2014-05-26
Posts: 1,118
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Re: A/UX and the djmemc 128MB SIMM support

So, that means the Q800 should also recognize the 128MB SIMMs as 64MB, right? That might be a good place to start.


Machine room (updated for 2019!): http://www.floodgap.com/etc/machines.html

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#3 2015-06-17 02:20:52

bbraun
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Registered: 2014-05-29
Posts: 1,064
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Re: A/UX and the djmemc 128MB SIMM support

Yup, it should.  Just be patient during power on for the super long memory test.

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#4 2015-06-17 02:21:50

bbraun
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Registered: 2014-05-29
Posts: 1,064
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Re: A/UX and the djmemc 128MB SIMM support

These SIMMs should be good.  They have to be in the 32x32 configuration to work right.

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#5 2015-06-17 23:27:06

ClassicHasClass
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From: Electron Alley
Registered: 2014-05-26
Posts: 1,118
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Re: A/UX and the djmemc 128MB SIMM support

Ordered!


Machine room (updated for 2019!): http://www.floodgap.com/etc/machines.html

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#6 2015-06-20 00:14:39

bbraun
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Registered: 2014-05-29
Posts: 1,064
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Re: A/UX and the djmemc 128MB SIMM support

auxram.png
This is with 3x128MB SIMMs plus a 32MB SIMM I had lying around, and the 8MB onboard.  I still had to create a RAM disk in System 7 to be able to boot, which is kind of a bummer since it'll ask to cancel or initialize the RAM disk on every boot.  But, you can give the system lots of processes, stack space, file handles, buffers, etc. and not worry about running out of RAM.
A/UX doesn't actually honor the RAM disk config, so there's no RAM disk under A/UX.  It's just necessary for the ROM and MacOS to boot in order to get to A/UX.

Without any tuning:

c650.root # pstat -m
53876 buffers: 0 busy, 0 wanted, 32721 done, 21154 nodev
1085 out of 1098 UFS inodes active
29 out of 100 processes active
92 out of 102 files active

Total memory = 434148K, currently free = 195128K

I should up the inodes and files here.

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#7 2015-06-20 02:41:21

ClassicHasClass
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From: Electron Alley
Registered: 2014-05-26
Posts: 1,118
Website

Re: A/UX and the djmemc 128MB SIMM support

How big a RAM disk did you create?


Machine room (updated for 2019!): http://www.floodgap.com/etc/machines.html

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#8 2015-06-20 15:40:03

bbraun
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Registered: 2014-05-29
Posts: 1,064
Website

Re: A/UX and the djmemc 128MB SIMM support

I made the RAM disk almost the full size, since the MacOS side pretty much just needs enough RAM to boot and load A/UX.  I don't know exactly, I just moved the slider all the way over and then back a smidge.

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