6 Jun
2018
6 Jun
'18
7:28 p.m.
On 06/06/2018 05:39 PM, Paul Koning via cctalk wrote:
Yes. "Same length wire" is how I first
heard it. When I started reading the 6600 wire lists I discovered that the reality is far
messier. The PPUs aren't too bad, that is a 4 phase clock, where consecutive stages
are clocked usually at 50 or 75 ns apart. For example, the consecutive stages of the
barrel are clocked (mostly) at 75 ns difference.
My project manager at the time was Mike Miller, who related that as an
EE fresh from the U of Minnesota, his first job at CDC was measuring the
coils of wire on the 6600 to which Seymour had attached a tag that said
"tune".
Some who had done early work as CEs related the differences between SN 1
and the regular production runs. Apparently, the floating-point divide
unit gave results that weren't duplicated by any other 6600.
Rick's story makes me wonder why nothing like that ever happened to the
DD60s at Sunnyvale. Since the systems were essentially full of QSEs
owned by Special Systems, a lot of dedicated block time for OS
development was available. I've witnessed coffee and coke spilled into
the things--and the ever-present ash tray on the side.
We used to be invaded by masses of crickets when the weather got
cooler--SVLOPS was surrounded by onion fields and bugs would find their
way inside. You could find crickets happily camping in your desk
drawers--and they got into equipment by the hundreds. A couple of the
CEs had a pet mouse that lived under the raised floor--I don't recall
his name.
--Chuck