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BeeryMiller

DREM FDD/HDD Emulator

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WOW $349.00 on Ebay?

Rich, that is Canadian dollars. The US amount would be US $265.84. But this is not the same one that Beery has been describing, the same manufacturer, but a different model, not sold yet.

The price may be higher or lower depending on demand.

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Hard to say if it will be cheaper or not. He has removed the daughter board simplifying the design, but making it so it will fit a drive slot. Either way, I will be in for one and hopefully will get it to work with the Geneve. I only have a few files on the real iron that are not on the MAME image. I am hoping either a MAME or MESS image will work on the device without anything special. I just do not have all those details yet.

 

In an earlier email several months ago, he indicated when the device was initially released, it would work with only floppies or hard drives (user selectable) initially. Then, with an update, it would support both 2 hard drives and 2 floppies simultaneously.

 

Beery

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The new DREM emulator product description has been posted at http://www.drem.info .

 

You can not buy it yet, but the details and manuals have been posted. Price is listed at $255.57, but I am not sure if that is US or Canadian dollars.

 

Beery

 

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The new DREM emulator product description has been posted at http://www.drem.info .

 

You can not buy it yet, but the details and manuals have been posted. Price is listed at $255.57, but I am not sure if that is US or Canadian dollars.

 

Beery

 

I believe that if this works, it will be a great addition to our systems, that's for sure. 255 for a hard and floppy emulator is not bad at all considering the work involved. As well as the piece of mind that our old MFM's can be backed up easily.

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I believe that if this works, it will be a great addition to our systems, that's for sure. 255 for a hard and floppy emulator is not bad at all considering the work involved. As well as the piece of mind that our old MFM's can be backed up easily.

 

I agree. If someone is contemplating a Gotek or Hxc and have a Myarc HFDC, then it becomes an obvious choice. I will make 2 x 120 MB hard drive images and will periodically copy those image files to my PC computer for backup.

 

What I am not sure is whether IMGTOOL for MAME will allow me to strip the header off the file to give me straight up sector by sector disk image and then if it is useable directly on the DREM. If not, I will have to format out an image, and use Tim's Port program to transfer a mass of files over from MAME to the real system.

 

Let's see, that will give the Geneve 9640 system an emulated WiModem232, HxC floppies, and DREM hard drives. Add to that the SCART monitor and Chris's new PS2 keyboard interface on its way to me, and the system is much different than it was from years ago.

 

Beery

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Beery, just use TIImageTool, Extract raw from CHD.

 

Remember, TIImageTool has exactly n+1 functions. :-)

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Beery, just use TIImageTool, Extract raw from CHD.

 

Remember, TIImageTool has exactly n+1 functions. :-)

 

Great, thanks for the information.

 

The last I recall on the V2 (?) CHD image, all sectors were laid out in one continuous manner with a short header. We are up to V4 (?) now, so I do not know specifics with that format as I also thought you had captured information between the sectors as well.

 

If you look at the manual for the DREM at https://www.dropbox.com/s/0l7q8mjjk0sqkze/DREM-2.User.Manual.pdf?dl=1starting on page 18, it indicates how the bytes/sectors are stored for floppies and further on for the hard disk drive. Can you confirm the way MAME handles the layout is the same, or whether a reordering of sectors would be necessary for either the floppy image or the hard drive image?

 

I just do not know how the HFDC DSR (TI or Geneve) lays out sector numbering between sides of disks and tracks, as well as cylinders and heads for the hard disk drive. If the format is different, a utility may be required or a n + 1 + 1 :) feature may be needed for TIIMAGETOOL.

 

The worse case, it is different and you format out a disk and just copy files over rather than copy a MAME image after preprocessing through TIIMAGETOOL.

 

Beery

Edited by BeeryMiller

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The raw format is simply a sector dump like the one for floppies, actually, a linear block addressing (LBA). That means that the resulting file starts with the 256 bytes of sector 0, then the 256 bytes of sector 1, ... up to the 256 bytes of sector 78720 (depending on the size, of course).

 

I'm not sure right now how this translates to CHS coordinates. This should be found in the HFDC code. I seem to remember that the sectors start at head 0, then go along the heads, before switching to the next cylinder, so this would comply with the format of DREM. You may have to try.

 

The additional information is stored as metadata in the CHD container, and it only concerns the interleave, the precompensation, the reduced write values, and the gap sizes. No gap contents are stored. The track layout is recreated by this description when the tracks are loaded on demand.

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He's got 100 units in this first production run with a 6 week lead time for whenever he needs the next batch.

 

I'm wanting to remove the hard drives and use these as their replacement. That way, I can much more easily create backups of the drives. The devices will also pull all necessary power that is needed from the PEBox drive connector cables.

 

I am not 100% sure, but if things work as the documentation describes, I believe I can pull the SD card from the real hardware, copy the hard drive image files over to MAME and use them directly.

 

Beery

Edited by BeeryMiller
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My two have not arrived yet. I will have a small window of time today should it arrive in this evening's mail. Otherwise, it will be either Sunday evening or Monday before I have a chance to look at it because I will be out of town. If you learn anything in the next 6 hours, let me know as my first attempts will be using MDM5 on a TI-99/4A system.

 

My intent is to create a 120 MB image, and have 2 hard drive images of that size on each system. If you take the approach to start from a clean image rather than trying to port over a MAME hard drive image, it should zip up really small. If it could then be uploaded here, it would save a number of people that go that route the hassle of formatting, etc.

 

For the most part, I will want to bring over my MAME Geneve HD image for the Geneve system and copy a few other source files onto it. For the TI system, I will still have a 120 MB image, but seriously doubt I will use more than 10 MB.

 

Beery

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Ksarul,

 

I got my unit connected last night and fought with some MDM5 issues running from a Horizon Ramdisk before I discovered loading MDM5 from the ramdisk was the source of some initial issues.

 

The SD card had a lot of files on it for the various platforms preconfigured, but nothing at present for the TI/Geneve as one would expect to be the case. You definitely want to connect a monitor to the emulator card with a keyboard so you can see if you are getting error messages, etc.

 

After I got my MDM5 issues resolved, it was getting late and I started to edit a 'defaulta.cfg' file from the WDC/MFM directory. It was setup with a 512 bytes/sec configuration. I edited it to 256 bytes/sec and change it from 17 sectors/track to 32 sectors/track.

 

I loaded MDM5, but MDM5 did not think a hard drive was connected. I need to confirm some cabling to make sure I do not have the 20 pin cable inverted as I gave up due to the time and needing to get up early.

 

I will not be able to do anything more until either Sunday evening or Monday evening after I return from a trip. If you have any success, please let me know.

 

If I can not get MDM5 to identify a hard drive presence, I will switch over to CFORM on a Geneve setup and see where things go from there.

 

Beery

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Keep in mind that MFM drives are "dumb" in the sense that they cannot identify themselves, unlike SCSI or IDE. The only way to detect the presence of a hard drive is by the SeekComplete and READY line, maybe also Index.

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Ksarul,

 

I have submitted a debug file of MDM5 attempting to format a hard drive to Oleksandr at Portaone following some communication I have had with him. He has checked the datasheet for the HDC9234 and it is very close to the WDC, but programmable and may have some minor deviations.

He's looking at the debug file now. Hopefully, something to report soon.

Beery

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Ksarul (and others),

 

The DREM does not presently have a configuration option that works for the TI-99/4A. Last night, Oleksandr and I were sending one another files back and forth. The Western Digital Controller implementation is close to the implementation in the 9234 chip, but not identical. Oleksandr resolved some of the issues, but we are not there yet. Oleksandr was pretty much on the fly adding extra code into BIN file controlling the DREM as each log file was sent his way.

 

I am going to send Oleksandry my HFDC as he already has a TI system but no HFDC for testing. Hopefully, it is anticipated this will expedite the process.

 

Beery

 

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Ksarul,

 

Things are getting closer. Oleksandr sent me another update and rather than using the WDC format, there is now a new format he has added. I've been able to format, and the first file copied appears to copy fine. Problem is, copying the second file copied in a batch has an error and aborts the process. Real close. About to generate another log file and send to him before I turn in.

 

Beery

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Good news, the DREM is working now with a single 20 MB hard drive image. I tried to add a second hard drive image at 16 heads, 32 sectors per track, and 1024 cylinders and hit what looks to be a buffer issue with the software. Issue reported and the developer, Oleksandr, has been very responsive.

 

(BTW, I thought I would be out of town today. The storms from the hurricane are blowing through the area, and not good to fly in rain...………). So, I am back home.

 

Beery

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