8271 Disc interface problem
I have a Model B with an 8271 disc interface which almost works. I'm using a Gotek drive which works with other machines in my collection, so I know there's nothing wrong with that.
The problem is reasonably simple to describe: The interface can control the drive and successfully get it to seek to any track, but any data it reads seems to be all zeroes. So *.0 or *.2 on a double-sided image shows 'Option 0 (off)' and no files, even when the option is 3 or 4 and there are files.
There's a Disc Doctor ROM in the machine so I can do *DZAP <track> and it will seek, but then shows an error and no data. I forget the exact error but it wasn't very descriptive - just a single character (not "disc fault at ..." or anything like that).
The computer also has an Econet interface, in case that makes any difference. DFS is in the DNFS ROM.
I have other disc interface components so I can swap all the individual chips with ease. Soldering and measuring voltages on the board is more of a problem because I'm a software person. Given these limitations, are there any easy things I can do to get this working, or get a better idea of what the problem could be?
I have a Model B with an 8271 disc interface which almost works. I'm using a Gotek drive which works with other machines in my collection, so I know there's nothing wrong with that.
The problem is reasonably simple to describe: The interface can control the drive and successfully get it to seek to any track, but any data it reads seems to be all zeroes. So *.0 or *.2 on a double-sided image shows 'Option 0 (off)' and no files, even when the option is 3 or 4 and there are files.
There's a Disc Doctor ROM in the machine so I can do *DZAP <track> and it will seek, but then shows an error and no data. I forget the exact error but it wasn't very descriptive - just a single character (not "disc fault at ..." or anything like that).
The computer also has an Econet interface, in case that makes any difference. DFS is in the DNFS ROM.
I have other disc interface components so I can swap all the individual chips with ease. Soldering and measuring voltages on the board is more of a problem because I'm a software person. Given these limitations, are there any easy things I can do to get this working, or get a better idea of what the problem could be?
Statistics: Posted by NJ_ — Sun Aug 11, 2024 6:51 pm