NeXT prototypes and hardware variations

[Nitro]

Ok, had to swap out the v59 ROM for a v66 ROM due to a system error 51. Works now.

[andreas_g]

Thank you very much! So this is really one of those machines mentioned in the headers. The board revision in SCR1 is set to 1 and it includes the new clock chip, while otherwise still including a non-Turbo chipset. Interesting, that even NeXTStep 2.0 supports the new clock chip. So these newer boards must have existed quite early.

[Nitro]

You're welcome, glad that I could finally help.    I have one other newer mono non-turbo NeXTstation and it has a date stamp inside the case - September 30, 1991.