I have, of course, been trying to stock more of Silvergate. Whether this will also impinge on the Abyssal Realms I don't know (though by the way I've got hold of some lovely material from I'll See It When I Believe It which I will be definitely incorporating all over the place, including the Abyssal Realms).
So, as it says in the title, this is probably what I should have put first in the posts about Moldvay. But, because I'm an idiot, I didn't, and I've had to go back looking for this. It's a corridor-generator from The Nine and Thirty Kingdoms - it's what I used to give me some content that I could build a section of dungeon from. I did what it suggested and used four letter-shapes (but I didn't bother to do anything fancy about rotating or flipping them, I just decided to 'not make them look like letters'). No proper map I'm afraid, as I have to preserve some mystery, but I did a schematic. The original shapes for my corridors are
... which is 'OSR' and the randomly generated letter '(lower case) g'. So now it stands for OSR gaming, or maybe OSR gangster. As per the directions for how to turn this into corridors, I mushed the letter-shapes together so they were all joined up and began treating them as per the instructions.
However, when I applied the rules for what happens on a corridor, as I hadn't established a scale, I guessed where 'every 60 feet' might be, to roll for doors and stairs and whatnot.
I ended up with 34 rooms, of which maybe 3 are really just broom-cupboards or hidden niches. I'm calling it '34 including 10a' anyway.
Another problem (after guessing scale) was that I didn't have anything to say what was on the other side of the door, at the end of the corridor, etc. The post on The Nine and Thirty Kingdoms says "I am assuming here that you are using tables borrowed from Appendix A or another random dungeon generator to roll for size and shape of rooms, type of door, what's behind each door, or other details as needed."
Well, no, unfortunately, I don't have any such table to hand, Moldvay doesn't include one. Going to have to do something about that, I really need dungeon-dressing tables. But I muddled through, mostly by just filling up some of the space on my map with pseudo-random shapes derived from Paint - circles, a star in one place, a couple of pentagons and hexagons, rectangles with square or rounded corners. Sometimes when it looked like two corridors might join, I joined them, sometimes I imposed rooms (joined or not).
One thing that seemed to make sense but that I have probably never done before - never, even though some such thing is heavily implied in Keep on the Borderlands, and therefore might be considered a 'standard' design feature for those of us of the Moldvay era - is the placing of a room at the end of a 'blocked' corridor. (I actually applied this solution twice, but ended up deleting one because I thought two in a area of less than 36 rooms was overusing the idea). There is a whole bunch of semi-ruined portions of this (sub-)level, but one of the ruined corridors leads to a room that is not accessible by any other means. Sneaky, huh? They'll just have to have a Potion of Gaseous Form or something. Not sure how they get the treasure out though...