<a href="https://www.computerweekly.com/news/252496560/Fujitsu-bosses-knew-about-Post-Office-Horizon-IT-flaws-says-insider" rel="nofollow">https://www.computerweekly.com/news/252496560/Fujitsu-bosses...</a><p>>For the first 10 years of Horizon’s existence, transaction and account data was stored on terminals in each branch before being uploaded to a central database via ISDN. Our source says this part of the system simply did not work.<p>>“The cash account was a piece of software that sat on the counter NT box, asleep all day,” he said. “At the end of the day, or a particular point in the day, it came to life, and it ran through the message store from the point it last finished. It started at a watermark from yesterday and combed through every transaction in the message store, up until the next watermark.<p>>“A lot of the messages in there were nonsense, because there was no data dictionary, there was no API that enforced message integrity. The contents of the message were freehand, you could write whatever you wanted in the code, and everybody did it differently. And then, when you came back three weeks later, you could write it differently again.”<p>And down further<p>>Speaking to Computer Weekly in 2015, the anonymous source told us: “The asynchronous system did not communicate in real time, but does so using a series of messages that are stored and forwarded, when the network connection is available. This means that messages to and from the centre may trip over each other. It is perfectly possible that, if not treated properly, messages from the centre may overwrite data held locally.”<p>>Four years later, former Fujitsu engineer Richard Roll wrote in a witness statement to the High Court: “The issues with coding in the Horizon system were extensive. Furthermore, the coding issues impacted on transaction data and caused financial discrepancies on the Horizon system at branch level.”<p>BUT the most important part<p>>So far, nobody at the Post Office or Fujitsu has been held accountable