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PEx + Sun Netra t 1125 = Sun Macintosh 1125/4U

Trash80toHP_Mini

NIGHT STALKER
In an alternate history, Sun bought Apple, continuing development of the iMac and Beige G3, all well underway before the second coming. The PowerExpress/9700 project was continued and further developed by Sun as the first RackMac, specifically targeted at the die hard content producing creative types who'd kept the dream alive in the mid-90s.

Be that silliness as it may, I've had a Sun 25th Anniversary Compact Mac in the concept stage for the longest time. Since I've been repopulating the main living area of my apartment. Flood damaged carpet has been replaced in the main living area. The PEx ROM test peripherals setup on top of the Netra in the collection rack was just cleared away to move the Rack and storage Boxen back from my bedroom onto the new carpet from whence they came. All of a sudden the notion hit and had just to be done. So I've begun converting the long somnolent Netra t 1125 4U monster into a bulletproof, industrial duty case for my bare PEx mobo.

NetraPEx-00.JPG

The ridiculous OEM, PSU had to go, it looks to have intelligent control over a sixteen signal line connection with the logic board? Its output lines are really heavy gauge on a pair of much oversized Molex connectors, no chance there, nor need for that much power.

The 9600 PSU from the many years old PEx-in-a-Drawer setup would fit behind the air intake fan in the front if I built a custom frame for its boards, but that's just not practical. So I'm at an ATX conversion installation within the confines of top sheet metal of the OEM supply and quite a bit of available cubic below it. That's my worst, but not really all that high a hurdle.

NetraPEx-01.JPG

This is the first hurdle, but not so really bad at all. Need to do an EPS file to hand off to one of my customers at work. He finally got a water-jet setup for his custom gasket fab. There will be a goodly section of this very heavy steel backplane plate washed away and a pair of missing of slot openings behind that sticker cut out to open the case to the PEx full card complement. At that point I can begin fitting this sacrificial 9500 logic board in place.

NetraPEx-05.JPG

I haven't had to drill out this many pop-rivets in a very long time, what a beast! 😲
 
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markyb86

Well-known member
I'm always interested in your projects so I'm definitely following to see where this takes you!
 

trag

Well-known member
Water jet cutter is nice. There used to be a guy on Ebay who sold plate steel by the pound cut to whatever pattern you requested.

I used his service to make VESA mounts for some early IBM/Samsung LCDs. I had to do a little bending, drilling and tapping.

Backet_Top.jpg

On_Arm_Propped.jpg



On_LCD_Oblique.jpg


On_Wall.jpg
 

Trash80toHP_Mini

NIGHT STALKER
UNIX workstation displays?

Been thinking water jet and realized I have a wet tile saw with diamond blade that's been in the closet for years. It's been waiting for me to cut the back off a Compact CRT, but I never built the two sided jig needed. Wet diamond blade should cut steel like butter?

Sections of the drive cages need to be removed for logic board clearance. One vertical optical bay vertical is just barelyy clear of the side of the board as shown in pic 2 above. The side of the drive is clear by an eith inch or so. I need to put a strip of electrical tape on the opposite sidewall to insulate the edge where the logic board buts up against it.
 
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Trash80toHP_Mini

NIGHT STALKER
NetraPEx-07.JPG

Maybe closer to a quarter inch, but well enough clear.

The other drive cages need to be cut back an inch and a half or so to clear the logic board at almost exactly their level and they need to be cut for vertical clearance, RAM gets in the way.

NetraPEx-08.JPG

Fun with power tools! :p
 

Trash80toHP_Mini

NIGHT STALKER
Power tools make their own loud music. I also like the quieter strains of hand tools. Making shavings with a hand plane may as well be a lullaby.

The two threaded nubbins on the vertical piece held one of two brackets holding a hot swap backplane for a pair of full height 3.5" Ultra SCSI drives, those must have made some kind of music!
 

Trash80toHP_Mini

NIGHT STALKER
No time to do his for a week or so, but couldn't go out of town without confirming that I can make the required cuts.

NetraPEx-09.JPG

No worries! Researching metal cutting, I found out the next rev of this inexpensive tile saw is #1 in Popular Mechanics 2021 Tool Buyers Guide. Not pro level, but well suited for DIY at about $90.
 

Trash80toHP_Mini

NIGHT STALKER
I can highly recommend this little wet tile saw for metal cutting, love it! Drive cage before:

NetraPEx-12.JPG

Drive cage after:


NetraPEx-11.JPG

I now have required clearance, access to RAM DIMMs and plenty of room to slide the PEx board back and lift it out after removing the PSU.

Haven't pointed out the great standoff assembly (white) that supports insertion of PCI Cards and the Processor Card:
NetraPEx-10.JPG

Tan plastic feet on the drive cage support strips appear to be the same height as the MLB standoff assembly. Had to cut them back to clear the soldertails of the DIMM slots. I can tweak them up or down if needed. Was a bit concerned about support for the DIMM sockets when changing memory around, but no problem!

I guess it's water jet time for the backplane, but that can wait a bit. I need to find a power extension cable to use the 9600 PSU over the short term
 

Gorgonops

Moderator
Staff member
The Netra T 1125 wasn't ringing a bell for me; I sometimes wake up in a cold sweat after nightmares about the little Netra T1 1Us or those gawdawful Enterprise 220/420 monsters. Looks like this was basically a Telco-racked version of the deskside Enterprise 250?

I'd call you a monster for butchering it except when it comes to these Sun servers I kind of want to help chop it into little pieces so it can't rise from the grave and hurt anyone else.
 

Trash80toHP_Mini

NIGHT STALKER
LOL! It appeared to work last time I fired it up quite a few years ago, but it's been nothing but a counterweight on the short TelCo rack in my display area. I was thinking about offering its intestines up to the Sun ghouls, but I'm too much of a procrastinator to sell anything in the TP.

It's giving up the ghost for a good cause. When I move sometime in the next eighteen months or so, I need to have the PEx mobo housed in something a bit sturdier than the plastic drawer it has lived in for so many years. This big mohonking 4U beast is way overkill, but it's being put to good use I think. 😬

BTW, used the wet tile saw to make nice cuts in relatively thin sheet metal this afternoon. wonderful toy!
 

joshc

Well-known member
I think this project is interesting and resourceful. Like you say, if you weren't using the Sun for anything else, may as well repurpose it - afterall, it is yours to choose what you do with it!

Looking forward to seeing the finished thing. Maybe you could share a little video on it when it's done?
 

Trash80toHP_Mini

NIGHT STALKER
I've never done a video for anything like this, but I try to document the steps with decent pics in the thread.

The Netra T 1125 wasn't ringing a bell for me; I sometimes wake up in a cold sweat after nightmares about the little Netra T1 1Us or those gawdawful Enterprise 220/420 monsters. Looks like this was basically a Telco-racked version of the deskside Enterprise 250?
Dunno what it was, I think it's dead now, but I'll take some pics of the board before I drive the stake through its heart. ☠️
 

Trash80toHP_Mini

NIGHT STALKER
Havn't posted a clear pic of just how much of the drive cage I cut away yet:

NetraPEx-13.JPG

Still room for one of my 2.5" UltraSCSI Savvio server drives in the lower 3.5" bay. The bays are configured for a full height 3.5" server drives.
 
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