A collection of tips for working with KDJ11 CPU boards.

Failed Tests

The KDJ11-B includes a variety of diagnostics in ROM that run on boot. When a test fails, there is a hidden option to bypass the test and continue. Simply press Ctrl-O (the letter, not the number zero), then 4, then ENTER. This will continue on, halting at the next failed test or at the boot menu.

J11 ODT & Cache

When a KDJ11 with cache powers up, the cache is enabled by default, even in ODT mode. Thus, even if a memory location is faulty, writing and reading to that location will appear to succeed.

The cache may be bypassed by setting bit nine of the Cache Control Register (CCR) located at 017777746. In ODT:

17777746/ 01000