Again it has been a long time since I have posted!  However I do have progress to report.  I now have OS8 booting from micro SD card!

This is not without problems though.  There are currently three problems that I know of, first writing to SD cards is not correct, I will turn to simulation to see if I can find the problem there.

The second problem is random crashes, halts or loops.  Currently I can think of three possible reasons, a timing problem, I will slow the clock down and see if that clears the problem.  Secondly I may still have an instruction bug that diagnostics don't catch.  It is possible that there is a bug in OS8 that makes it go off into the weeds with user input.

The third problem is that DEC used essentially a six bit "ASCII" code.  This was before the ASCII code was approved.  I had been using Minicom as my terminal, it does not cope with this well.  I am now using picocom, it is doing better, but still not correct.  When playing with this I suspect OS8 is getting bombarded with crap!

I have modified the state machine and the operations in the states to improve the timing of the device.  I hope to be able to have the basic PDP8e, with 10 K words of memory, the EAE and the RK8E disk controller in one build.  This will push the logic usage up past 50%, it gets harder and harder to meet timing as the logic usage goes up.

I am now using OS8 Combined Kit (ock) release of OS8.  This is essentially that last release of OS8 for standard PDP8's.  There may have been further releases for the DecMates...  The ock image files were generated with  tools from the PiDP8I project:  https://tangentsoft.com/pidp8i/.  Many thanks...