Wayback Wed: MPE gets its last millicode fix
November 29, 2017
Ten years ago this month HP's labs delivered its final fix for MPE/iX millicode. The patch demonstrated the last critical repair of the OS by the HP development labs. It had been 16 years since HP had to do a fix for the 3000's millicode. The 2007 millicode patch was crucial whenever a customer's applications accessed mapped files and utilized Large Files, those which are 4GB or greater in size
HP introduced the Large Files feature in 2000, just after the community had cleared Y2K challenges. The corruption could occur if any one of five out of the last six bytes of a Large File failed to transfer correctly. Corruption introduced by MPE/iX is so uncommon that the patch became essential—and a way to gauge how much the community might lose when HP's labs would close up.
The labs were ready in a way the customers rarely saw. HP announced the bug with repairs and white papers already available.
OpenMPE sought an opportunity to take a role in the repairs. OpenMPE advocates showed concern that binary repairs like this one would present a challenge to application developers who need to integrate them into MPE/iX in the future. OpenMPE wanted to do this work. The advocacy group never got its opportunity to participate in the development work for 3000 sites.
HP's repair rolled out four years to the day after the company ended sales of the 3000. The development of this type of patch, a binary-level repair, remained available throughout 2009 and 2010. At the time of the repair, HP had not yet licensed its source code for MPE/iX. Delivery of that source code wouldn't take place until 2011. HP's binary patches for the corruption were not done in source code.
Large Files was a feature gone sour, by HP's own reckoning. The vendor was trying to remove the code from customers' 3000s. A 2006 patch was designed to turn off Large Files and get those files on the system converted to Jumbo files, which are much better engineered.
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