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Intersystems 64K Dynamic RAM Card.
This was Ithaca Audio's (later known a Intersystems) 64K Dynamic RAM card.

Intersystems 64K RAM board

The InterSystems 64K Dynamic RAM board was one of the first S-100 dynamic memory board to take full advantage of the S-100 bus IEEE-696 specifications.

Its features included:
Byte or Word Data Transfer. Whether you're were using an 8 bit processor or a 16 bit processors, the board's data bus automatically adjusted to the requested word width. You could even run a 16 bit processor and an 8 bit Direct Memory Access Controller  concurrently in the  same  bus.
Standard or Extended Addressing- The memory board could be addressed in either the standard 16 bit address space (64K)or in   the extended 24 bit  address  space  (16 megabytes).Onboard arbitration and sequencing logic- This circuitry allowed continuous DMA transfers of any size and error-free operation during waits,  halts,  or  resets.
High Speed Operation. The board could be configured for either 2 MHz or 4 MHz operation without wait states- All timing was completely  IEEE  S-100 compatible.Precise delay line timing- There were no one shots, oscillators, or RC delays.Used  both  transparent  and default  refresh.
Compatible with  front   panels.
Designed  to  use  either  4115 or  4116   type memory chips.
Phantom and Error. These S-100 lines assist in bootstrapping and memory protection.
Low Power/Low Heat Design. Low power not only meant less drain on the system power supply, but higher reliability and longer chip  life  as well.
Damped Array. All lines driving the memory array included small series damping resistors, reducing array noise and improving reliability.
Wait State Generator. One wait state could optionally be generated on  the board  for M1 or  any board  access. The manual can be obtained from here.

Conversion of this 64K Dynamic RAM board to a 256K Dynamic RAM board.
Intersystems sent out a note after the board came out that allowed the conversion of the board to a  256K RAM board. I did this and it worked fine but it is not for the faint hearted.  The update can be found here.


Other InterSystems S-100 Boards
64K Dynamic RAM    8K RAM   EPROM   IA-Display   FDC   IO-Card    Z80-Series-II    Z80
   ADDA Board   EPROM Burner 
FPB   256K Dynamic RAM   16-64K EPROM
  HDA   Z80-Series_III   6-SIO  EPROM Emulator   RTC Board



This page was last modified on 10/25/2013