I worked on Merced post-silicon, and McKinley presilicon. I wasn't an architect on the project, I just worked on keeping the power grid alive and thermals under control. It reminded me of working on the 486: the team was small and engaged, even though HP was problematic for parts of it. Pentium Pro was sucking up all the marketing air, so we were kind of left alone to do our own thing since the part wasn't making money yet. This was also during the corporate wide transition to Linux, removing AIX/SunOS/HPUX. I had a Merced in my office but sadly it was running linux in 32-bit compatibility mode, which is where we spent a lot of time fixing bugs because we knew lots of people weren't going to port to IA64 right away, and that ate up a ton of debug resources. The world was still migrating to Windows NT 3.5 and Windows 95, so migrating to 64 bit was way too soon. I don't remember when the linux kernel finally ported to IA64, but it seemed odd to have a platform without an OS (or an OS running in 32-bit mode). We had plenty of emulators, there's no reason why pre-silicon kernel development couldn't have happened faster (which was what HP was supposed to be doing). Kind of a bummer but it was a fun time, before the race to 1 GHz became the next $$$ sink / pissing contest.
I was at HP pre-Merced tape-out and HP did have a number of simulators available. I worked on a compiler-related team so we were downstream.
As for running linux in 32-bit compatibility mode, wasn't that the worst of all worlds on Merced? When I was there which was pre-Merced tape-out, a tiny bit of the chip was devoted to the IVE (Intel Value Engine) which the docs stated were supposed to be just good enough to book the firmware and then jump into IA64 mode. I figured at the time that this was the goal — boot in 32-bit x86 and then jump to 64-bit mode.
Yes, yes it was! It ended up playing a much larger role for marketing transition efforts, larger than it should have. But the Catch-22 has been analyzed to death.
