Up for Auction: Memory from the First Computer in Space

Jon Elson elson at pico-systems.com
Thu Oct 29 12:22:17 CDT 2015

On 10/28/2015 11:48 PM, Brent Hilpert wrote:
> Very interesting to hear of another scheme, but it's not 
> clear whether it applies to the Gemini auction memory. The 
> BiAX scheme shows cores with the holes (apertures as 
> they're called in the business) perpendicular to each 
> other. In contrast, the Gemini auction cores have two 
> apertures with the same orientation (a figure 8). 
Yes, but I'm pretty sure the concepts are related.  The 
remanent flux in the non-volatile side of the core affects 
the flux hysteresis in the volatile side, so when you flip 
the flux polarity on the volatile side, you can see some 
effect caused by the non-volatile side.
>  - 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 

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.


More information about the cctalk mailing list