SD SYSTEMS - ExpandoRAM Rev E Dynamic Memory Card S-100, F16K4DC, HM4716A-4N  

In Perfect condition ! Sell as is due its age !

SD Systems really built the business with their dynamic RAM cards which they called ExpandoRAM cards.  The initial  boards utilized 16K dynamic memory chips (4108's) and could be configured to work with 1,2 3 or 4 banks.  This was quickly increased to 64K RAM chips (4116's). Thereby allowing one S-100 board to take care of the complete 64K address space of the 8 bit Z80 CPU's used at the time. The boards were quite configurable and would fit in well with other memory cards within the 64K memory space.  They responded to the PHANTOM S-100 line so ROM's on CPU cards worked fine.
      The boards were sold initially as kits but later were also sold fully assembled and tested. There were three major version of the board called the ExpandoRAM, ExpandoRAM II and ExpandoRAM III. Each had numerous revisions.  The ExpandoRAM III was IEEE-696 compatible. Memory access was about 367ns - fast at that time. The ExpandoRAM-III which came out in 1983 could be configured with 4164 chips allowing for a RAM card capable of addressing 256K of memory. It also ran with a 4MHZ Z80 with no wait states.



Shipping :

Europe : The price is for Air Priority Shipping with tracking number – takes about 8 – 15 working days !

USA and other Countries : The price is for Air Shipping with tracking number – takes about 15 – 25 working days !

Every Item is carefully packed and put in special box or special envelope for that use. The Items We send had an Tracking Number and can be tracked all over the World.

Return Policy Details:

We Accept Money Back and Replacement. The Important thing is the Buyer to be satisfied ! Please if you have any questions feel free to ask us. We will answer them As soon as we can.

Feedback :

Dear Customers, Most of the Computer Parts we sell are about 30+ years old. We test them twice – one time before the listing and one after the Item is Sold. We packed them with anti-static bags and put them in boxes.

!! Please if you have any issues with the parts when you test them contact us before leaving an feedback and We will do everything we could to help you  !!

Jul 30, 19 ; 1154