dtgreene: (Soloing the Abyss in other versions is quite a challenge, and if you haven't recruited all 8 companions, you get kicked out at the end.)
stryx: I found soloing the Abyss in the PC version much more easy and convenient than navigating a whole party. I was playing as a mage, got a magic wand and magic robes, stocked up on reagents, got poisoned and breezed through the Abyss. Sadly the game wasn't having any of it.
If you want to solo the Abyss and still be able to complete the game, you could recruit everybody else and just let them die; while you need all characters to complete computer versions, they don't all need to be alive. I saw a speedrun of the Sega Master System version that beat the Abyss with 3 characters alive, and I suspect it might be faster with 1. (I note that this wasn't a very good run; the runner didn't seem to know the trick of being poisoned to avoid speep.)
(Also, IIRC, in the room before what I call the "room from hell", there's a sleep field that can remove your poison, and you *really* want to be poisoned for the "room from hell"; trust me on this. Fortunately, the Energy spell can be used to poison yourself.)
Anyway, some relevant differences in the NES version:
* The poison trick does not work; a poisoned character can be put to sleep. Also, note that poisoned characters take poison damage during combat and in dungeon rooms, though not in towns.
* After clearing a room, the game leaves combat mode and you can walk around the room just like you can walk around the overworld or a town. This eliminates the problem of navigating a whole party through the dungeon.
* There's no need to recruit everyone to beat the game. You do need to be an Avatar to enter the Abyss (which has no random encounters so you can't lose your Avatarhood there), as opposed to computer versions where the Avatar check is at the *end* of the Abyss.
* The Energy spell works differently; it's an attack spell (stronger than Fire but Weaker than Ice) that creates a 3x3 field of fire. Not useful for poisoning yourself (but there's not much point in the NES version), but very helpful for winning certain battles quickly, provided you don't care about EXP (and overworld encounters scale to your level, so you might want to stay at level 4).
By the way, if anyone is looking for an Ultima game to speedrun, the Sega Master System version of Ultima 4 could probably use some love, as the run on YouTube isn't that great. (I expect it to still be about 2 hours when optimized, however, which is a lot longer than most other games in the series.)