09-15-2018, 11:44 AM
Hi, I'm the one who experimented with Mac images a while back, and I'm afraid I simply have had zero luck copying or writing Mac 400k/800k disk using the SCP. It has been a little while since I last tried, and I have not yet tried a8rawconv.
I believe there were several different issues.
First, I never had any success simply copying/writing a direct SCP dump of any non-index aligned Macintosh disk. Each attempt resulted in at least one bad sector per tack. Similar issues with Apple II disks. I only have a few factory original Mac titles, but none of what I have was index aligned (I can see this with HxC). I was using splice mode.
Also, when dumping SCP files and decoding Mac non-index aligned disks with PCE, I have found I have needed three revolutions, and I must tell PCE to use the second revolution. Otherwise I would see some bad sectors. Logically, 2 should be enough, so there must be some limitation with PCE's decoding algorithm.
There is a method for using PCE to convert 400k or 800k IMG files (sector images) to a flux stream. However it seemed to store some bogus RPM or bitrate data. Running the results through HxC partially ironed things out, but the results would not write using a SCP. (a particular different flux writing device somehow compensates for this mess and succeeds in writing). Of course, such a manufactured flux image is index aligned.
I believe there were several different issues.
First, I never had any success simply copying/writing a direct SCP dump of any non-index aligned Macintosh disk. Each attempt resulted in at least one bad sector per tack. Similar issues with Apple II disks. I only have a few factory original Mac titles, but none of what I have was index aligned (I can see this with HxC). I was using splice mode.
Also, when dumping SCP files and decoding Mac non-index aligned disks with PCE, I have found I have needed three revolutions, and I must tell PCE to use the second revolution. Otherwise I would see some bad sectors. Logically, 2 should be enough, so there must be some limitation with PCE's decoding algorithm.
There is a method for using PCE to convert 400k or 800k IMG files (sector images) to a flux stream. However it seemed to store some bogus RPM or bitrate data. Running the results through HxC partially ironed things out, but the results would not write using a SCP. (a particular different flux writing device somehow compensates for this mess and succeeds in writing). Of course, such a manufactured flux image is index aligned.