Re: PDP11 M9301-Yx ROM dumps And now that I think of it, I wonder if the ROM in the board I dumped had any errors? I have two, I should dump the other one and compare - but I forget which one I dumped, and I fried one of them! :-( The board did 'work', but I only used the console emulator, and the serial line loader, so there might be an error elsewhere (e.g. in one of the disk bootstraps). Well, the second is definitely wrong; not sure about the first, I'd have to figure out what it's doing with that data word. That's odd, that doesn't make any sense. Hmm, does that mean that it actually froze at 165102, or at 165106? (I.e. is the display the address of the current instruction, or the next one?) That shouldn't freeze the machine - unless you had a double bus fault (i.e. trying to push and old PS/PC, and the SP is gubbish). Try loading the SP with the address of some working memory before you start the test, and see what happens. You might also deposit 6/0/12/0 in locations 4-12, so that if it does see an illegal instruction or NXM, it will just halt. Well, I'll keep working on it anyway. No, but I do have a un-annotated dump in octal. Can you point me at a description of Intel HEX format, so I can whip up a converter program? (Which will also take an array of PDP-11 words, and split it up into the 4 different ROM chips, since each word is spread across all 4 chips.) I already have a program to read my octal dump things, so I'll just have to tweak that a bit. I'm going to need to start blowing ROMs soon (including some sets of 9301-YF PROMs, for the one I zorched), once I get my 29B hooked up, so I might as well start with this... Noel