28 Jul
2012
28 Jul
'12
2:34 a.m.
Really? It interleaved fetch / execute with two sequencers. Quite
sophisticated,
but it does make sense if they both ran the same code and the operations
took some time, or you had multiple drives to service.
As I type this, it is apparent to me, that this is the only way to
go.to reduce part count and eliminate duplicate firmware.
Dave McGuire wrote:
On 07/28/2012 01:53 AM, Eric Smith wrote:
Chris Elmquist wrote:
That would be breat! But wait, aren't the HSCs all
PDP-11 based? I
know the HSC50 has an F11 in it, and the HSC70 (and later) use a J11; is
there also a bit-slice processor in there?
If I desolder these and read them, do we really
have use for the bits?
I've written a 2901 disassembler before. It was for
something that used
a custom sequencer rather than the 2909, but it wouldn't be hard to hack
it up to use the 2909. So if Tony doesn't have the code for his
disassembler handy, I could hack one together fairly quickly.
I've been considering doing such a thing anyhow for the UDA50, KDA50,
and HSC microcode. IIRC, they use two 2910 sequencers for two
independent threads of execution.
Neat!
-Dave