DEC Compatible boards was RE: [pups] Re: PDP11 - RQDX1 standalone format utility? --> XXDP

000137 145702

There isn't very much to know about the a.out header, and what you are doing looks OK although I would probably have set a_text to 160000 and left a_data and a_bss as 0. While I am not really familiar with the BSD boot code that vtserver uses when loading a program I am almost certain that it will use the entrypoint address in the a.out header and not just jump to address 0. (remember it's an actual program loader that understands a.out format, not just something that only knows how to load a boot block and jump to it) This is confirmed by the fact that the code you are patching into the image at address 0 is wrong if you want it to get you to the restart address. In your example you have: 000020/ 000167 000022/ 145702 If this was loaded at address 0 in memory and the boot code jumped to address 0, you would end up at 145706 *not* 145702 (of course, you might very well get lucky and still land on an instruction boundary, but you would have skipped the first 2 words of the restart code). If this code were really necessary (and I'm 99.99% sure that it isn't) you would want either: 000137 145702 or: 000167 145676 _______________________________________________ PUPS mailing list PUPS(a)minnie.tuhs.org http://minnie.tuhs.org/mailman/listinfo/pups