Intersystems
64K Dynamic RAM Card.
This was Ithaca Audio's
(later known a Intersystems) 64K Dynamic RAM card.
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
FPB
256K Dynamic RAM
16-64K EPROM
HDA
Z80-Series_III
6-SIO
EPROM Emulator
RTC Board
This page was last modified
on 01/08/2011