256K Dynamic RAM Card.
This was Intersystems final Dynamic RAM card.
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
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
64K Dynamic RAM
FPB 256K Dynamic RAM
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