Having seen ruzzmon's comment above I decided to give this example one more try. Previously I have got no further than the error message so I made the suggested change and tried again. This now compiled cleanly ( no errors, plenty of warnings!) however it still failed to get beyond the first part of the code. By adding print statements I was able to establish that where the interrupts are turned on it never continues. The line that seems to cause the problem is the one that says:- INTRMASK = BIT(INTRLINE_TIMER0); // Enable Timer0 interrupt Serial.println("S2e."); INTRCTL=1; <---- problem line Serial.println("S3."); //Setup VGA Hello World The green lines are the prints I added. The output was:- SmallFS Started.Opening Mod File from SmallFS.4D 2E 4B 2E Number of patterns: 23Memory needed: 96440Loading sample data ptrAll loadedS2.S2a.S2b.S2c.S2d.S2e.As can be seen the code stops after the line INTRCTL=1; Now I'm not an expert on Arduino or FPGA but it seems to me that this is trying to enable interrupts. However I cannot find where the interrupted vector is set up. I would appreciate some help in how to debung this problem. I assume it should call the ZPU interrupts routine "_zpu_interrupt" but don't understand how it knows that is the routine to call. I would also like to say that I think the progress in design lab is excellent I have recently purchased a Papilio DUO -2 MB, and the new design lab persuaded me to dig out my older Papilio pro and logicstart megawing whilst waiting for the arrival of the shields that I have ordered. Yours Peter D Hull
