Tony Duell wrote: If you're referring to mine, I don't think that's the problem, because even power-cycling the machine and restarting the program doesn't fix it. I'm pretty sure it was a software bug in Moonlander, causing the display list to get corrupted. Since my GT40 ROMs has different ROMs than the standard ones listed in the manual, and which don't seem to perform the same function, I had to reassemble the loader to a different address. I picked 037000. It worked, but Moonlander overwrites it. It takes so long and is so error-prone to toggle in the nearly 256 words of the loader that I haven't yet tried it again. I think what I really need is the RIM loader and a description of the RIM format. Source is on my web page: http://www.brouhaha.com/~eric/retrocomputing/dec/gt40/ If I were burning roms, I'd change the target of the two branches in the GETSIX routine to branch back to GETSIX rather than to L.BAD. This allows carriage returns, line feeds, etc. to occur in the middle of the download. On the other hand, it means that a corrupted download is less likely to signal the host for automatic error recovery. Since I was trying to download that was a non-issue. But it turned out that the "ASCII download" feature of the program would crash if the lines were too long. Probably a lazy programmer using the C gets() function, which is a no-no.