How am I wrong #1

There are probably going to be many of these. As I pour more over how it was done, I will find many things I forgot over the years....

I can't completely get rid of all the mixer chips, Well we'll see. Besides just connecting the registers, the mixers were used to connect different bit output positions to input positions. So, for example adder output bits 4,5,6,7 all get wired to AR input bit 5. They use this to do shifting of bits left or right. I may be able to limit this by using a SHIFT register directly. If I can find an appropriate one.

What I don't know now. Why the 2 bit shift to only the right? What was it's purpose?

While I'm here. the KI did NOT have the standard 74XX TTL adder chip. Perhaps it didn't appear until too late in the design cycle? I would have guessed incorrectly that I'd find 7483 chips in the adders, but no. The Dec "Magenta" M142 module used an adder put together by Dec using less sophisticated IC's.

We find yet another proprietary Dec chip in here. The DEC1074H which is a WIDE and or invert chip. Probably the 'merchants' didn't have call for a chip this wide (4 ands into the or), but Dec felt it needed enough of them to have someone build them. These are used in a few different FlipChips in the KI.

So I now know of at least 3 proprietary Dec chips that were used. Holy cow! And one of them was in the KA10!