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Building a Clone MITS 8800

maxtherabbit said:
I don't see anything circled but I attached a pic which should explain it I hope. Vertical distance between these points
View attachment 1293178
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Sorry, I forgot the picture in my last post. I've edited the post to add it.

The dimension appears to be 0.6".

The stack up from bottom to the top of the rail is:
- side member, 0.062" thick
- nut
- washer
- 0.25" long spacer
- 0.125" angle

Keep in mind I don't know if my specimen was assembled "correctly" or not and it's the only one I've handled.

Bill
 
maxtherabbit said:
Would you be able to tell me the distance from the top face of the horizontal mounting rails that hold the backplanes to the top face of the bottom sheet metal cabinet?
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On my Altair - the right-angle rail on which the backplane is bolted is 0.5" tall, and the bottom edge of the mounting rail sits 0.25" above the floor of the enclosure. Therefore, distance between floor of the enclosure, and top surface of the mounting rail, is 0.75".
 
Alright here is the final draft of the power board. Due to the height of the capacitors, it will not clear the full width fan on the original altair, but a modern 12VDC 120mm fan will easily fit in it's place due to its reduced thickness.
s100 power.pngs100 power back.png
 
Ok one final revision. Moves the 16V and fan connectors slightly forward to get more fan clearance. Also got a little more current capacity on the negative rail just in case.s100 power.pngs100 power back.png
 
I sent the board to fab. Made a couple revisions since I posted last, most notably adding M4 mounting hole to allow it to be mounted to the existing screw bosses in the altair clone cabinet using 12mm standoffs. Here's the setup mocked up in my clone cab20250129_125148.jpg
 
The power board works great! I'll try to get the kicad files and a BOM up to github tomorrow. The only very minor issue is that the leads on those SBX2540-3G schottkies are ever so slightly thicker than a standard DO-201 package. They still fit in the through holes with minor persuasion.

I'm getting unloaded voltages of 9.5V and +/- 18.5V. Fan is getting a solid 11.8V from the 7812 while operating.
 

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Last edited:
I checked on the price of those clone cases, only $310. You have no idea how tempted I am to get several of them and put my Windows PC Guts in them replacing the beige beauties I'm rocking now :)
 
DougM said:
I checked on the price of those clone cases, only $310. You have no idea how tempted I am to get several of them and put my Windows PC Guts in them replacing the beige beauties I'm rocking now :)
Click to expand...

Hi,

I heard from some buyers, it's more like $350 after shipping.

I have one of the original Mike Douglas cabinets (he passed the files over to Chris to continue having them made to sell), but now I'm building my own cabinets from Oakwood.

I like the "homemade" look rather than the copy look ... the best thing is these cabinets cost about $30 to build.

1741747231956.jpeg

1741747247629.jpeg

1741747313890.jpeg


I've been posting the vector files for laser/waterjet cutting on my website: http://www.brainless.org/Altair/Repository.html#section20



.

.
 
Does anyone here make cases? How do you get the texture? And what is the color? It occurred to me that I can bend my own aluminum, so all I really need is the face plate.

Maybe the better question is, how can we get the texture? Probably this texture is from some expensive commercial process.


1741998586900.png
 
DougM said:
Does anyone here make cases? How do you get the texture? And what is the color? It occurred to me that I can bend my own aluminum, so all I really need is the face plate.

Maybe the better question is, how can we get the texture? Probably this texture is from some expensive commercial process.
Click to expand...

High quality new production Altair reproduction enclosures are available from this group:
adwaterandstir.com

Altair Reproduction Case

An order has been placed with the manufacturer, which typically takes 60 days. Sign up for an email notification when they are back in stock…
adwaterandstir.com
Sold out right at this moment, but it looks like more will be in stock soon.
 
Chris ordered them in small batches because he didn't know how fast they would sell out. also there was some bugs to iron out found during the initial run.

the initial sale went fast because people were hungry for the Douglas case. i suspect the next batch he orders will start to sell fast then stock is going to sit longer then your comfortable with.
that will make a 3rd batch order possibly not happen or be limited even more.

there is a reason that the clone Altair cases stopped being made because they would start to sit around for years before getting sold.
 
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