SCELBI 8b PCBs

The SCELBI 8B backplane, SRAM and memory expansion boards just arrived. They may take a couple of weeks or so to check out. If they work, I’ll be able to get floating point SCELBAL up and running on an 8B for the first time in a very long time, and so will you. There is a semi-reproduction that has run SCELBAL, so maybe not the first, but it all depends upon how you classify that system. To start with, I’m building a minimal, barebones, chassis mainly to allow check out of the SRAM and get SCELBAL running.

You will notice that there is a stack of cards involved. The big question is whether I finally screw up a layout and have to ditch one of these batches of cards. To date, I’ve never made a small prototype run of a few boards to check my work. There were prototype’s made of a few of my smaller cards, but they were either made on prototyping boards or etched here at home, where the cost is almost nil, compared to professionally made PCBs. The benefit of this rather risky approach is that I save a great amount of money by not making what would be rather expensive prototypes. This directly translates into a lower cost project for you and me. In addition to the risk of making a complete batch of dud cards, another downside is the great amount of time spent reviewing the layout before I eventually pull the trigger.