I've made some progress with the Alley Cat image.
The original disk has some odd sectors, specifically the 1st sector of track 0, and 17th sector of tracks 17, 19, 21, 23, 25.
I tried to make a clean backup disk, but occasionally I still get a "Bad allocation table" error.
The disk is readable if you boot from Disk BASIC first. The first 8 files are weird, though, with no names, and I can't access them.
The rest of the files are interesting. They look like assembly files, and there's a program called DUAD88, which was an old program development tool for the PC-8801.
I extracted all the files I could from the disk. Looking into cat1.e, for example, you can find the text:
Quote:
F1 kitten
F2 House Cat
F3 Tom cat
F4 Alley Cat
(C) 1983 Synapse Software
(C) 1985 KOTOBUKI-RAISON
So that's encouraging. But since these are all assembly files, I think they need to be assembled and converted into machine language before running the program. I tried to use DUAD88 to do this, but the options are cryptic and I don't really know what I'm doing.
Here's everything I have so far - the original disk image, my backup image, the extracted files, a copy of N88 disk BASIC, and a floppy containing the full DUAD88 tool.
Hopefully somebody else will know what to do next.