pm sent

I had the same issue with my HS. Needed that impossible to find board.

Check with Keith over at K's Arcade. That's the only place I found one. They're super rare, therefore expensive. BUT you gotta have it!

K's is THE fastest shipper around FYI.

When i bought my High Speed, clearly my board was screwed up, sent it to K's for repair. He let me know it would take a few weeks, so i got impatient and bought an 11a (i think) that was converted to high speed on ebay, payed quite a bit for it ($325), but i'm not the type of guy that can't have something in non working condition, so i was in whatever mode.

I still went through with the repair as for i figured a spare would be helpful since i'm drawn to mostly sys11 games. That was $180.

My advice, watch ebay, and pay what you have to pay. Never hold out for a lower price, demand is high, supply is low. The time to buy it, is when you see it.

ebay.com link: Williams System 11 Original MPU

This is not mine, but a 30 second search of ebay found it.
My suggestion, bid and forget about a lower price.
If you don't, i'm considering it, lol.

I pulled a MPU from f-14, mostly working, couple transistors shot I think. Let me know if you want any info.