Not much done with the floppy stuff over the last few weeks. To say I've had a tough time at work recently would be the understatement of the century. Managed to sit down last night with a clear head to sort out this problem sector. Firstly it's obvious the post...
TDTool V1.3 has been released. I have now added a WRITE function, bit of a hack but it makes the program a whole lot more useful. You can download it from Aminet here. Or you can download directly from this server: TDTool.lha and TDTool.readme. These links will always point to the latest version.
Nothing to report on the floppy side of things. Still need to sit down for a few hours to study the sector with the wildly varying bit cells. On another note I have just bought a DIP42 adapter for the EPROM programmer. This allows me to program 27C400 chips which...
TDRead has been renamed and released to Aminet as TDTool. You can download it from Aminet here. Or you can download directly from this server: TDTool.lha and TDTool.readme. These links will always point to the latest version. I spent some time on it before release, mainly adding a new DEVICE command line parameter that...
Spent the last few days analysing the data from a particular sector I am having trouble reading. To setup the analysis I changed the PIC code to seek to track 159 (my problem track) and then captured a couple of rotations using Logic. Then I made a copy of the...
Track 159 is the one of the problem tracks. Very crude analysis in Excel shows wildly varying bit cells. Very hard to say at this point if it's the problem as I have not compared them against the rest of the disk. The problem is related to an earlier post...
Last night I scanned about 6 disks in and tinkered with the MFM decoding logic. Most of my time was spent with genuine faulty disks, for half of the night I got that dreaded click-click-click-click sound as the head passed over a tiny piece of dirt. Out came the cotton...
Added a piece of code to PushBit() to check if all 1760 blocks have been found. If so then it writes them out to disk in the ADF format. Take a look below; this screenshot was taken from WinUAE booting as an A1200 with a Workbench3.1 disk. The disk scanned...
Not much done today, but got and hour and a half in this evening. PIC code has now been modified to scan the whole disk, pretty much as follows: Select Drive Motor On Seek to Track Zero Select Side 0 Wait 250ms Select Side 1 Wait 250ms Step head ...and...
Managed to get half an hour in here. Making the code a bit more analytical. It now tells me if a SYNC word was found mid-sector and also reports how many non-sector bytes were discarded before a sync work was found. It's looking exactly as I expected: Sync Marker found**...