Mark IIb and breaking the 20 Gflops barrier

Now that Mark II has been operational more regularly, I’ve noticed that working on it in the current case is really inconvenient. Something with a removable top would make a lot more sense (which is why machines of a similar design had this feature), but when I started designing Mark II I couldn’t find anything […]


There were a number of errors in my last post. Error #1 The most egregious was in my interpretation of the high-performance Linpack (hpl) results. I was mystified by the fact that as I added nodes to the cluster performance would improve to a point and then suddenly drop-off. I attributed this to some misconfiguration […]

Back in Bl..ue

Thanks to a gracious gift of gadgetry for Fathers Day, I was able to spend last weekend increasing Mark II’s computing power to maximum capacity! Not only did I have the parts, but I also had the time (again thanks to Jamie & Berty) and had very ambitious plans for pushing Mark II across the […]

Pump the Brakes

Looks like work on RAIN Mark II will be slowing-down a bit for a couple of reasons: First, the snow has receded which means work that can only be done during the month we call “summer” takes priority over anything that can be done inside (plus there’s just lots of fun things to do outside…). […]


Based on feedback, conversations and thoughts about the short and long-term goals of the RAIN project I’ve decided to make some changes to the naming convention of the series. I’m renaming RAIN Mark II from Personal Supercomputer to Supercomputer Trainer. The term “trainer” refers to education-oriented machines and systems (typical of the 70’s and 80’s) […]