I'm not getting involved this time. Last time I tried, I just make myself look silly. I don't know anything about the internals, except that they used braided- wire memory to store the little "executive" (= a small OS with real-time capabilities) which controlled the computer. I think the OS was written in a language called HAL/S, although I may be getting the Apollo Guidance Computer mixed up with the Space Shuttle computer. I have no idea if the source or binary is available. The thing was designed to interface to radar systems, electronics, power controllers, rocket engines, etc., so I think a simulator would be pretty hard to write. However, the manual is available! NASA published it as a report. I think after the terrible fire that killed three astronauts, NASA had to rethink the entire Apollo program, so they did a lot of soul-searching (along with the accompanying paperwork). The user interface is rather spartan, because the only displays are numerical. There are many specialized commands ("verbs" to NASA) and some operands ("nouns"). One command might resynchronize the gyrocompasses, others do simple navigation, etc. I don't believe there's a "Land On Moon" command. :) I have the manual on my hard drive, and there might be a URL. The first time I saw the AGC (one of them? how many were there?) it was on display, but not working, at the Computer Museum in Boston. I don't remember if they put plastic in front of the keypad... there wouldn't have been much point in pressing the keys anyway. The other time I saw the AGC, it was in a cardboard box in the Computer Museum History Center warehouse in Moffett Field. They had just moved in -- I was poking around -- "What's in THIS box? Oh, it's the PDP-1 broken down to individual System Modules! And this box is the AGC, and that box..." Rather awe-inspiring actually. As I said, you would need details about all the other hardware. Yes, it would be cool, but I'm not very optimistic. -- Derek