S100 Computers

Home S-100 Boards History New Boards Software Boards For Sale
Forum Other Web Sites News Index    
Intersystems 256K Dynamic RAM Card.
This was Intersystems  final Dynamic RAM card. 

Intersystems 256K RAM

The InterSystems 256K Dynamic RAM board was took full advantage of the S-100 bus IEEE-696 specifications-

Its features included:
Byte or Word Data Transfer. Whether you were using an 8 bit processor or an 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.
Parity error checking for all read and write cycles.
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, 4 or 6 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.Uses  both  transparent  and default  refresh.
Designed  to  use  64K dynamic memory chips.
Phantom and Error. These  S-100 lines assisted 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 Ml  or  any board  access.Simple board setup. The board had only 4 jumpers!

The manual can be obtained from
here.  The schematic can be obtained 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