Honeywell Alert / Re: Up for Auction: Memory from the First Computer in Space

Brent Hilpert hilpert at
Sat Oct 31 01:40:48 CDT 2015

On 2015-Oct-29, at 10:22 AM, Jon Elson wrote:
>> - Another topic: what is a Honeywell Alert machine? Searches are just bringing up some current-day "Honeywell Instant Alert" messaging system. 
> It was a 24-bit DTL machine designed for the X-15 project, and then used in a number of other projects.  It is about 25 Lbs (without memory), draws 25 A at 5 V, and runs off a 3 MHz clock.  It is constructed of 6 multilayer PC boards with ceramic flat packs on both sides.  The boards are attached to a motherboard with flexible PCB, so there are no connectors inside the machine.  They chose this for reliability, it makes it REALLY hard to work on.  There are cold plates between the boards that conduct heat down to the baseplate. The instruction set was apparently modeled after some Honeywell business machine of the time.  It has no floating point hardware, but DOES have hardware multiply and divide.
> I have gotten it to run, sort of.  Since I have no memory for it, I can jam op codes into the data in plug and observe the speed at which the memory address ripples.

Very neat, too bad the memory is gone.
Is building a new memory with modern stuff a consideration (enough documentation .. )?

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