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GRiDCASE 1537: A computer designed for/sold to the US Military&Intel svcs.

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I now have, in my possession, a system that is not supposed to still be in one piece: A GRiDCASE 1537, a variant of the GRiDCASE 15xx series that has a substantial amount of shielding designed explicitly to minimize radio frequency emissions that could be intercepted ostensibly by bad actors. It was a system that was not sold to the general public, and was only available through GRiD's government services shell company, GSCS, and only if you had permission to acquire a unit from the appropriate superior.


I'd only seen vague mentions of this unit in GRiD sales literature, as case studies.


Because these systems were designed for classified information processing, they were supposed to be destroyed upon decommission. A few of these wound up as surplus, and somehow survived. By all accounts, there are, maybe, 5 of these left in the world.


Which is why I was _VERY_ surprised, when on a lark, I typed in GRiDCASE, hoping to find a 1520 or 1530 to be used as a development testing unit for my PLATOTERM development, and I find somebody selling a 1537 TEMPEST for $1100.


My eyeballs popped out of my head.


As it had happened, I had recently sold a bunch of excess hardware and software via eBay, so I had some extra cash, and after a lot of gnashing of my teeth, I decided to pull the trigger.


Now, what one of these units was doing on eBay, is strange enough. The fact that this unit was in Pervouralsk; a remote part of Russia, is truly one of life's great mysteries.




A bit about the unit:


The outside:


The case of the unit is black painted magnesium, with a rough matte finish, which, while not scratch resistant, is _extremely fingerprint resistant, as well as fending off some liquid spills. It is NOT waterproof, however.


The whole thing is black. black as black can get. It looks like the tycho monolith, very intimidating and imposing. This is what you would imagine a spy to have and use.


It is a clamshell design, GRiD pioneered the entire clamshell computer design with the Compass, and they extended it here with a larger screen, adding an internal floppy and/or hard disk, as well as a battery in most configurations, to make it a self contained portable.


This specific TEMPEST configuration does not have a battery though, due to various requirements for processing classified data. Instead, the battery compartment is filled with a 16 volt DC-DC transformer, which is bolted into the chassis. A fan is added to this DC-DC supply (unlike most GRiDCASE machines)




The inside:


This laptop was produced for roughly two years, starting in 1991. This was a beast of a laptop by 1991 standards:


* 80386SX 20mhz, which can be upgraded to an 80486SLC. (I did this on my original 1530 I once had)

* 4 megabytes of RAM

* 120 megabyte Conner mil-spec hard drive. (Only 5 specific hard drive models can go into this unit, period.)

* Chips&Technologies chipset and VGA (C&T 455), which can do 640x480x16

* Electroluminescent Display panel (ELD), with a characteristic bright yellow self-illuminating glow, the EL display has a quirk in that it only displays 640x400 in VGA mode, the bottom 80 pixels are cut off

* 77 key mechanical keyboard (yeah, it's a fully mechanical keyboard)

* 3.5 inch 1.44mb floppy

* built in SCSI adaptor


All for a cool price of approximately $13,940 in this configuration, which for the US Govt is...a bargain. ;)




A bit about the TEMPESTing:


The laptop is TEMPEST certified, this means that there has been a substantial amount of EM shielding added to the unit. There is shielding around:


* The power supply

* The display and its driver circuitry

* the motherboard, which has a few bits of sub-shielding around critical parts, such as the processor and memory.

* There is shielding around the floppy drive

* There is also shielding around the hard drive

* There is shielding around the connectors on the back, as well as individual sub-shielding for certain connectors (the keyboard and VGA)

* Every interconnect is surrounded by braid shielding

* The display interconnect also has two long iron toroids surrounding the braid.

* There is a sensor attached to the hard drive tray, which detects if a hard disk is in the cradle, and therefore if tempest integrity is maintained. If the bay is open, the computer displays a warning indicating the tempest integrity can not be maintained. My sensor is malfunctioning, so i always see this message, my system boots anyway.




Here are some pictures of the unit in action, in its new life:




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This is very cool. Any chance you system has *any* expansion module installed? I'm trying to find *any* photo or accurate drawing of any module for the 1500 Series, particularly the detail on the male connector that mates to the back-plane in the module socket. I realize the tempest system is probably different though.

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nope, that whole section of the machine is completely non-reachable, it's miles and miles of shielding, and the power brick inside the system is a DC-DC converter that is permanently bolted into the space where any expansions would go. My brick is a metal external AC-DC transformer.



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Ports are numbered thusly:



2. VGA

3. RS-232



6. RS-422


The Expansion/POWER module is permanently inside the unit, and can not be removed without unscrewing from the chassis.


Note the KEYBOARD connector looks very strange. This is for a very special 9 pin TEMPEST shielded keyboard. Unobtanium.


Note the keyboard/VGA connectors are in a seperate sub-assembly. This is an additional layer of shielding on top of the shielding for all of the connectors on the back.


Note the RS-422 connector. This is a particular connector that I've only seen in military applications. Wanting to know more about what used it.


This is also a late model GRiDCASE, which means that the 5 side-wiper sockets for ROM programs aren't on this unit.



Edited by tschak909
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Wow, yeah, that is totally different from the stock units (understandably). Pretty cool unit though. I think I saw that one on Ebay, but there was no way I was going to drop that kind of cash on a system. I had a hard time justifying the $320 I paid for my GRiDCASE 1520, since past auctions sometimes went for less that $100, but usually not more than $250. Oh well, the price of hobbies I suppose. ;-)

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that's the gas plasma display. Beautiful output too, a huge upgrade from the LCD panel, I had a 1530 in that configuration in the 90s. It needed the BIG external battery to get a decent use time out of it. :)


This guy uses a thin-film electroluminescent display, which is an even bigger power sink. While I could fashion a battery for it (the DC-DC inside expects a stable 16.5V), i'm just going to keep it mains only for now.



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@doctor_x: Do you still have it? Do you want to sell it?


@tschak909: I was told by an avid Compass owner that there is a calibration procedure to turn down the brightness of the EL display, and he recommended doing so to increase the lifetime of the display. Not sure if that applies to the plasma too? My 1520 is the orange plasma and I love it! :-)

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