Quadibloc <
jsa...@ecn.ab.ca> wrote:
> On Tuesday, August 31, 2021 at 11:14:58 AM UTC-6, John Levine wrote:
>
> > Once you realize that a bunch of identical elements on a single chip
> > can communicate a lot faster than separate chips, and if they are all
> > the same, they don't all have to work and you can route around the bad
> > ones, the story writes itself.
>
> They were going to use a wafer-scale memory chip as a peripheral for the
> Sinclair QL, but the company making that one *also* failed, so making very
> large chips even when they were built of multiple identical components
> was _also_ profoundly challenging.
http://www.computinghistory.org.uk/det/3043/Anamartic-Wafer-Scale-160MB-Solid-State-Disk/
"The Wafer Stack has a Nat-ive Mode Interface and optional SCS interface: the
native mode interface has access time of 200 microseconds and average
transfer rate of 1.6Mbytes-per-second, 5Mbytes burst. With SCSI, access time
is under 1mS with average transfer rate of 3Mbytes-per-second. Power
consumption is a hefty 42W maximum at 5.25v and forced air cooling is
needed. Designed in an 8-inch form factor the Wafer Stack can contain up to
eight wafers - four storage modules, for 160Mb capacity. OEM samples,
including wafer controller and SCSI cost $11,680 for the 40Mb version,
$33,590 for 160Mb. Anamartic sees the Wafer Stack being used particularly in
high-volume transaction processing systems."
Contemporary HDD was about 20ms latency, so that's a fair bit better. But
transfer rate sounds awful - for comparison a 3.5" HD floppy disc was
250KB/s. You could stick 8 floppy drives in parallel and get the same
transfer rate.
Theo