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This is a photo of the connector

I have done continuity tests on the 3 pins.
1 is obviously ( from the continuity tests ) a ground pin. 1 is switched by the power switch. 1 has resistance and seems to change impedance when the power is switched on.

If anyone has any information on this connector, voltages and pinouts that'd be super useful.

Some extra pictures:

This is a custom ( I think ) board

Custom board? I think so based on the quality of the fabrication.

They pre-modded this to have an exposed swappable CMOS battery... but it's 6v?

They pre-modded this to have an exposed swappable CMOS battery... but it's 6v? The original I think was 3v.

Shot of full back w/ high density ports

Shot of full back w/ high density ports

Matt Joyce
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  • It's surely been modified for space use, so noone can help you except the guys who did the mods. You could use factory original 1530 as a reference to undo the mods, but I'm confident it would destroy its value as a space item. – Agent_L Aug 04 '16 at 08:59
  • I'd like to avoid disturbing the physical item, but restoring it to working order would be worthwhile. In addition pulling the software off before it bitrots is of even greater concern to me. – Matt Joyce Aug 04 '16 at 15:10
  • IMHO the safest way of pulling the soft off is to temporary move the hdd into another, operational computer. – Agent_L Aug 05 '16 at 09:46
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    That sounds a lot easier than it actually is. The HD is buried down deep inside the laptop and I am pretty sure I'd have to damage the plastic bolts to get it out. If I can avoid doing that, I'd like to. – Matt Joyce Aug 05 '16 at 14:42
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    I think every sign on earth and the sky says: get an unmodified 1530 and practice on it. – Agent_L Aug 08 '16 at 09:21
  • Not useful at all really. Can't 'practice' on it since it doesn't have the modifications I am concerned about. – Matt Joyce Aug 08 '16 at 12:52

3 Answers3

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The IBM laptops were flown unmodified and a special "brick" was used to convert the Orbiter 28 VDC to the regular power supply voltage and current used by the laptops. The "brick" is shown as DC PWR SPLY in this excerpt from the Orbit Ops Checklist. enter image description here

Grid dates from an earlier time but I doubt they modified anything but the connector. Do you have info on what a regular Grid used? If no, it looks like the company still exists, they might know. http://www.griduk.com

My roommate worked on these in 1983-1984 but I didn't know details.

Organic Marble
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I have an unmodified commercial GRiDCase 1520. The external DC connector is labelled 16V, and the output of the AC/DC convertor brick states that it is 16.25V. The GRiD Compass was the unit designed specifically for NASA/DoD use, the Case was a commercial product, and I doubt that they produced a significantly separate design for Shuttle use (though they have clearly added a more secure DC connector than the commercial barrel connector).

GRiDCase 1520 rear view, power brick removed GRiDCase 1520 power brick, inner connector

Grimxn
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  • That's helpful! Thanks. However, while they didn't do a custom run of 1530s for NASA, McDonald Douglas did do some heavy customization of the laptop internally resulting in a 40k price tag on these units over the 3-4k for a stock unit. Amongst many other things they replaced / modified the psu. So, I don't know for certain that it still uses the same power input as the stock unit. It is however useful to have pictures of these components and the words written on them. Thanks for that. – Matt Joyce Aug 03 '16 at 17:59
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    Does that glyph on the back with the broken and unbroken lines beside the "16vdc" tell you anything? (I am not a EE).... – Organic Marble Aug 03 '16 at 18:00
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    It means DC. Versus the waviness of AC. – Matt Joyce Aug 03 '16 at 18:02
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    @MattJoyce - given your photo, one of the mods they clearly made was a fan vent just left of the brick cavity. I assume this was to help with the well known issue, most prevalent on the Compasses, of the lack of convection cooling. It's not clear to me from your photo, but what is in the brick cavity in your model? Having said all that, it seems daft of MD to have changed the internal DC, whatever they did "externally"... – Grimxn Aug 03 '16 at 18:19
  • According to my reading this is something they do on ALL the PGSC systems. It has to do with heat dissipation in 0 gravity being fundamentally different. That being said, I've heard the grid systems ran extremely hot. What's in that cavity I believe is a custom board that replaces the two 'telephone' ports with two high density ports of unknown nature. – Matt Joyce Aug 03 '16 at 18:23
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    I can confirm that the GRiDs all ran extremely hot! We used them extensively (both Cases, and, originally Compasses) for portable marine navigation, and it was a GRiD salesman who first told me the story about the Compasses (which had no fan at all) overheating due to lack of convection in 0G... – Grimxn Aug 03 '16 at 18:32
  • added some further pics. I need to get a pic of the internal PSU board would be good to see if it matches up to the stock one. They did wire one of the pins in the power plug to one of the pins in the battery / psu / expansion bay. They also wired on of the pins back to the power switch... so they were mucking about there for sure. – Matt Joyce Aug 03 '16 at 18:34
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    ...sorry, I'm not skilled enough to disassemble the Case - it still works, so I am am not minded to hack away!!! – Grimxn Aug 03 '16 at 18:38
  • heh the case disassembly is surprisingly simple on these. under the rubbers are 2 philips heads... after that. most of the outer housing comes off just by pulling in the right direction. It's kind of a beautiful design from a servicing standpoint. I'll have to post a video. – Matt Joyce Aug 03 '16 at 18:40
  • I've ordered a PSU expansion unit similar to yours ( I used the Part Number to find someone who still had a couple collecting dust on a shelf, so thanks! ). I'll do some testing to see what's coming out of it, and dig into the laptop further to see if that looks like a safe alternative to using the shuttle connection point. – Matt Joyce Aug 04 '16 at 19:58
  • Using the external power adapter and a DC voltage power supply ( for the cmos battery ) no luck powering on. One time got a 5 high pitched beep error code. One time ( prior to adding the cmos voltage ) got a 2 LOW PITCH beep error code. – Matt Joyce Feb 28 '17 at 00:25
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That’s an MS3116 connector, used on US military equipment. If I had to guess I’d say it’s a size 8 shell. The tech specs are available on the Defense Logistics Agency website and everyspec.com, and connectors are available from DigiKey and Mouser.

okto
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