Tell you about it...

[clh333]

I just installed the software and configured the hardware this afternoon, so I have a learning curve ahead of me. In other words, don't expect anything useful any time soon. But I do have 8" disk drives and disks and an adapter / interface so in theory at least I may be able to test the fluxengine with an 8-inch drive. I do know that it can be done with a Kryoflux.

I post on the VCF as clh333 and you can send me an email at [email protected] or [email protected]. I am Charles Hudson Cleveland, Ohio, USA.

[clh333]

Sorry for posting (anonymously) on the cowlark.com site. Henceforth I will use my github account.

As I commented on the cowlark site, after some experimentation with the command syntax, I created a copy of a SSDD disk using a Tandon T50 SSDD drive. The disk was a TRS-80 Model III LDOS 5.x OS disk. FE documentation says these disks are a variant of the ibm standard and I inferred that I need only specify them as "ibm".

I was misled by the documentation ("using...") which I misinterpreted: "To access a real disk, leave out the filename (so :t=0-79:s=0)." Well, I left out the "-s", thinking it referred to a source file and therefore was un-necessary, before ":d=0,:s=0,:t=0-39". After several tries I realized my mistake and then struggled to formulate a file spec. Eventually the planets aligned and I was left with an image.

I tried to write this image back to a blank disk using the same drive as had read the image. There were no examples under the TRS-80 heading for write command syntax so I tried whatever I could think of but so far nothing has clicked. I assume that I do not need to specify "write TRS-80", but I haven't found the syntax yet.

I'm not sure which parameters I need to specify and in what order: whether I need to specify the geometry; in what order to specify the .img file; whether the output device needs to be specified if there is only one; what other cues I need to supply.

Despite my troubles I think this represents an advance over its predecessors. The decoding of the flux - that extra step - promises rewards of increased accuracy and portability of the imaged disk. As I mentioned earlier I have lots of early systems, disks, drives and formats with which to test its capabilities. It really is a remarkable piece of work.

Thanks, -CH-

[davidgiven]

Unfortunately writing TRS-80 disks isn't currently supported: writing is harder than reading, because reading can autodetect most of the settings while writing can't. Also, I need real hardware to test with, or at least access to someone who has real hardware.

The good news is that TRS-80 disks are a variant of standard IBM disks so it should be possible to write them with the generic IBM writer using the right combination of parameters. See http://cowlark.com/fluxengine/doc/disk-ibm.html for documentation. The bad news is that they're pretty complicated. Also, I believe you have a 40-track drive on the TRS-80? Do you have a 80-track one as well? There are problems with writing 40-track disks with an 80-track drive which needs some experimentation, so I'd prefer to get the 80-track version working properly before tackling 40-track disks.

The issue with TRS-80 disks is that they use non-standard parameters in a number of places, and will require images to be written in two passes (the directory track uses different parameters than the rest of the disk).

If you can attach a disk image --- preferably of an 80-track disk --- I can attempt to figure out the commands you'll need and get back to you.

[clh333]

Thanks for your reply. I do have the ability to write an 80-track as well as a 40-track image. I understand that the directory track on a TRS disk is not DOS-standard, and I can see that a two-pass approach would be required. I was wondering how that would be handled. (BTW I have references on all the details of the directory structure.)

Complicating matters, I believe, is the fact that not all versions of the DOS wrote the directory to the same track. They tended to want the track in the middle of the disk, probably for performance reasons, but the early standard (Model 1) was single-density, 35 track, directory on 17, while the later standard was double-density, 40 track and directory on 20.

I do not have a Model 1 nor do I have access to one, but as a member of the VCF I know there are others who do. But let's leave that for last: all my machines are either Model III or Model 4, which have either SSDD or DSDD 40-track drives. Not many Model 1s survived and even fewer disks, I believe. I will create an image of a 40-track and 80-track disk and attach them here.

Given the difficulties you have mentioned I think you don't need to worry about finding the right parameters for writing the image that I have created to a TRS disk: I was mostly curious to find the right syntax. But if I can help you advance the project I will be happy to do so. I have lots of different machines, lots of disks, 3,5 and 8-inch, and lots of time.

Tandy was not the only company to write an OS for their machines; there were at least four. One of the more unusual features of the TRS Model 4 was that a company called Montezuma Micro released a version of CP/M 2.2 that ran on that machine. MMCPM, as it was known, had the ability to format and write to disks of several other manufacturers' specifications.

Thanks again for your reply, and please don't let my inquiry be a bother to you. I'm really impressed with your work and pretty sure you have other responsibilities beside this project. We'll sort this out in time.

-CH-

[Icekhaos]

Any updates to this? Specifically 8 inch stuff. I have a hundred (believed to be) blank disks in my closet I really want to image.

[davidgiven]

It should now be possible to make this work, if you're still interested. The configuration system is completely changed and there are more detailed profiles per disk format, so it's possible to specify that the directory tracks get different sector markers.