KA10
From Computer History Wiki
The KA10 was the first generation of PDP-10 processors (themselves, exact re-implementations of the earlier PDP-6 architecture). It was built out of discrete transistors, on short single FLIP CHIP cards.
It was used in the first DECsystem-10 models, running TOPS-10. It was also the machine on which the ITS and TENEX operating systems were developed, after the machines were modified to provide paging (the KA10 normally only provided 'base and bounds' memory management hardware).