>
> On Wed, 22 Jun 2016, Chuck Guzis wrote:
> ...
>> Its illegitimate relative, KRONOS, made extensive use of ECS for support
>> of the PLATO system.
Not quite. KRONOS treated ECS (rather clumsily) as a kind of disk. PLATO just
bypassed all that and managed ECS directly, as memory the way it was originally
designed to be used. After startup, PLATO would own all the ECS and do
transfers directly, without any OS involvement. It would also use ECS for
inter-job communication, and for communication with PPU programs. For example,
PLATO disk I/O uses both request queues and data buffers in ECS, which the PPU
program accesses. Ditto for terminal I/O.
This is how PLATO could support 600 logged in highly interactive users on a
pair of 6500 (low end 6000 series, single issue) machines.
paul
