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by tomcam 1866 days ago
I would totally love to read a blog post about this. One can imagine an embedded tools gig where this would be important for a long-term support. Did they also do something like buy multiple copies of A specific hardware configuration of the target computer for preservation?
1 comments
gumby 1866 days ago
I don't remember what they did on the host (development) side. This was more than 25 years ago.

They were a major phone switch manufacturer (long since absorbed by someone else). Their original design was, IIRC, a Z8000. As those parts were EOLed they shifted to the 68K and wrote a Z8000 emulator for the 68K. They later shifted to the PPC and ported their Z8K emulator to the PPC. We supplied a frozen version of the GCC PPC cross compiler. They had their own frozen version of a Z8K toolchain I think.

Their SLA was something like "less than five minutes of downtime per decade" -- no rebooting, realtime performance, no other interruption -- and they believed their extreme conservatism helped them get there.

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tomcam 1865 days ago
Hold on, I just realized something.

Does this mean their hardware may still be running on a Power PC that is emulating a Z8000 that is emulating a 68000?

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gumby 1865 days ago
It would have been "running on a Power PC that is emulating a 68K that is emulating a Z8000". We used to joke about that.

But in fact they changed from "running on a 68K that is emulating a Z8000" to "running on a Power PC that is emulating a Z8000".

They ported their Z8K emulator from 68K to PPC which wasn't super hard. When the PPC was designed it was planned as an upgrade path from 68K series (remember it was a JV between Apple, Motorola and IBM; the first two, at least, had vested interests in making that transition as easy as possible).

This whole stack of emulation sounds crazy but given their needs, it wasn't.

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tomcam 1865 days ago
Thanks for scratching my itch. Fun fun story with just the right ending.
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tomcam 1865 days ago
> "less than five minutes of downtime per decade

Wow.

Well, if they were willing to pay…

Thanks very much for that wonderful piece of history.

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