Paul Koning wrote:
....DEC RISC took three tries (Titan, Prism, Alpha),
and in that
case all three were built as real hardware rather than being
abandoned while still in the paper stage.
Prism is what Cutler renamed the "SAFE" (Streamlined Architecture for
Fast Execution) RISC machine project after stealing it from Alan
Kotok's Advanced Development group in Marlborough MA. The *MAJOR*
change (at first) was that they renamed all the data types to full VAX
compatibility/stupidity. ie; "16" became "word", 32 became
"long" and
64 became "quad". I seem to recall some other changes: One of SAFE's
registers was always zero, and Prism moved it to the other end of the
register file. The wikipedia entry says Prism eventually shrank to a
32-bit machine.
We were aware of Titan (a Unix workstation), and were aiming at
64-bits with VAX data compatibility, running VMS.
I was in the working with Al Blackington (who had a low -- two digit?
badge number) on "VAST" a VAX Assembly language translator, which took
output from the VAX assembler after macro expansion, and eliminated
all the unused CISC side effects.
I was doing an instruction scheduler (based on work by Dave Orbits?)
after reading the papers from Fisher's VLIW project at Yale that
became Multiflow. Kotok had a very open management style and forwarded
lots of emails, so we all got to see the train comming at us...
I wasn't aware that Prism ever generated hardware, but I left DEC not
longer afterwards....
Phil