SDHxC to emulate a IBM3740 Format?
SDHxC to emulate a IBM3740 Format?
Hi Jeff,
i have difficulties to emulate the original IBM3740 Format.
My Settings:
IBM FM / One Side / Auto Gap / 77 tracks
Bitrate : 500000
26 x 128Byte sectors
360RPM
Starting sector: 1
The Diskcontroller i use is a FD1771-01.
When i operate the CP/M system with real 8" drives (NEC FD1165), all is working properly.
An created empty floppy using the above parameters is not readable (sector not found).
I have no idea what is the problem.
Regards, Frank
i have difficulties to emulate the original IBM3740 Format.
My Settings:
IBM FM / One Side / Auto Gap / 77 tracks
Bitrate : 500000
26 x 128Byte sectors
360RPM
Starting sector: 1
The Diskcontroller i use is a FD1771-01.
When i operate the CP/M system with real 8" drives (NEC FD1165), all is working properly.
An created empty floppy using the above parameters is not readable (sector not found).
I have no idea what is the problem.
Regards, Frank
Re: SDHxC to emulate a IBM3740 Format?
Can you try to dump the disk with imagedisk ? :
http://www.classiccmp.org/dunfield/img/index.htm
also : what is the system using this floppy disk drive ?
http://www.classiccmp.org/dunfield/img/index.htm
also : what is the system using this floppy disk drive ?
Re: SDHxC to emulate a IBM3740 Format?
Hi Jeff,
the image, what i want to use is an Dave Dunfield *.imd image (use BB1.imd).
When i extract those images to a 8" disk, all is working properly.
The system that i have in use, is an Ferguson Big Board 1.
Frank
the image, what i want to use is an Dave Dunfield *.imd image (use BB1.imd).
When i extract those images to a 8" disk, all is working properly.
The system that i have in use, is an Ferguson Big Board 1.
Frank
Re: SDHxC to emulate a IBM3740 Format?
If these IMD image work on a real 8" disk with your system, convert them with the hxc software should do the trick.Frank wrote:Hi Jeff,
the image, what i want to use is an Dave Dunfield *.imd image (use BB1.imd).
When i extract those images to a 8" disk, all is working properly.
The system that i have in use, is an Ferguson Big Board 1.
Frank
IMD files are directly supported by the hxc software.
What is the behaviour of the HxC with this board ? (Led / LCD behaviour).
Re: SDHxC to emulate a IBM3740 Format?
Hi Jeff,
that is what i have done.
But it does't work with all the linked *.imd files.
The firmware is updated to the newest version, you provide on your site.
When i compare the data of the sectors with your new "Track Analyser", all the content of the sectors is OK.
Frank
that is what i have done.
But it does't work with all the linked *.imd files.
The firmware is updated to the newest version, you provide on your site.
When i compare the data of the sectors with your new "Track Analyser", all the content of the sectors is OK.
Frank
Re: SDHxC to emulate a IBM3740 Format?
Hi Jeff,
attached some pictures from the different timing of the real 8" drive and the SDHxC.
Both uses the same imd file as source.
attached some pictures from the different timing of the real 8" drive and the SDHxC.
Both uses the same imd file as source.
- Attachments
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- 8inch_data_after_sep_.jpg (77.67 KiB) Viewed 10678 times
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- 8inch_data_org_.jpg (82.28 KiB) Viewed 10678 times
Re: SDHxC to emulate a IBM3740 Format?
And here the pictures from HxC.
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- HxC_data_after_sep_.jpg (82.34 KiB) Viewed 10678 times
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- HxC_data_org_.jpg (81.86 KiB) Viewed 10678 times
Re: SDHxC to emulate a IBM3740 Format?
It seems that the VFO/data separator work in both case.
Regarding the data width difference , this probably because the HxC use a larger data pulse than the floppy disk drive.
Where have you took these measurement ? Right at the 1771 pins ? Can you take the VFO output clock too ?
what is the width of the floppy disk drive data pulses ?
Regarding the data width difference , this probably because the HxC use a larger data pulse than the floppy disk drive.
Where have you took these measurement ? Right at the 1771 pins ? Can you take the VFO output clock too ?
what is the width of the floppy disk drive data pulses ?
Re: SDHxC to emulate a IBM3740 Format?
Well, after a quick look at the 1771 / FD1165 datasheet and Ferguson Big Board schematic, i think that i have found the cause of the issue :Jeff wrote:It seems that the VFO/data separator work in both case.
Regarding the data width difference , this probably because the HxC use a larger data pulse than the floppy disk drive.
Where have you took these measurement ? Right at the 1771 pins ? Can you take the VFO output clock too ?
what is the width of the floppy disk drive data pulses ?
In external VFO mode the 1771 wait data and clock pulses from the VFO with a width under 350ns (150ns<>350ns).
The FD1165 generate data pulses with a width under 250ns (200ns +/- 50ns).
all ok... but:
The problem is that the Ferguson Big Board don't have the monostable circuit generaly used at the data input. So if the the data width pulses are wider than 350ns, the 1771 is not supposed to work correctly.
So the possibilites to get this work are :
- add a monostable circuit to reduce the data pulses under 350ns.
( this maybe done by a simple resistor/capacitor circuit :
http://www.premiumorange.com/daniel.rob ... stable.gif)
Or
- try to bypass Ferguson Big Board VFO and turn 1771 in internal VFO/data separator mode (XTDS = 1). It can support pulses up to 1000ns in this mode.
Re: SDHxC to emulate a IBM3740 Format?
Hi Jeff,
thank you for your answer.
One of the very first tryouts was to use the internal data separator in the FD1771. This doesn't work.
I give the monostable multivibrator (LS123) a chance on the weekend, if there is time.
Is there a chance to implement a variable pulse-pause output parameter inside in the SDHxC?
The board i don't want to modifiy and leave it as it is.
Frank
thank you for your answer.
One of the very first tryouts was to use the internal data separator in the FD1771. This doesn't work.
I give the monostable multivibrator (LS123) a chance on the weekend, if there is time.
Is there a chance to implement a variable pulse-pause output parameter inside in the SDHxC?
The board i don't want to modifiy and leave it as it is.
Frank
Re: SDHxC to emulate a IBM3740 Format?
Yes this problably the best choice. this circuit was commonly used to make this job on some FDC board. I will try to find an schematic.Frank wrote: I give the monostable multivibrator (LS123) a chance on the weekend, if there is time.
No, unfortunately this is not possible with the actual hardware. The USB version vhdl code maybe modified to reduce the pulse witdh.Frank wrote: Is there a chance to implement a variable pulse-pause output parameter inside in the SDHxC?
Re: SDHxC to emulate a IBM3740 Format?
Hi Jeff,
the shorting of the pulswide is working now over a 74LS123 up to about 450ns.
I am now able to read the contents from a "empty disk", created with the right parameters (all tracks, all sectors).
When i export the BB1.imd over "LOAD" and the export it to the SD-card, then i am only able to read track 0.
With the right parameters and "LOAD RAW" the BB1.imd and then export to SD-card, i am able to read all tracks with the right content.
Is there a way to convert the *.imd files to a *.raw file?
Frank
PS:The file BBCPM.IMD is not loadable in the software, why? Creating a real disk with IMD.COM has no problem with the BBCPM.IMD.
the shorting of the pulswide is working now over a 74LS123 up to about 450ns.
I am now able to read the contents from a "empty disk", created with the right parameters (all tracks, all sectors).
When i export the BB1.imd over "LOAD" and the export it to the SD-card, then i am only able to read track 0.
With the right parameters and "LOAD RAW" the BB1.imd and then export to SD-card, i am able to read all tracks with the right content.
Is there a way to convert the *.imd files to a *.raw file?
Frank
PS:The file BBCPM.IMD is not loadable in the software, why? Creating a real disk with IMD.COM has no problem with the BBCPM.IMD.
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- wrong data.jpg (125.44 KiB) Viewed 10668 times
Re: SDHxC to emulate a IBM3740 Format?
When i "reimport" the BB1_IMD.hfe in the new 2.xx HxC-Software and look on the datas in the sectors,
they are indentically in track 0 and in track 1. Also in track 2 and 3 and so on....
Frank
they are indentically in track 0 and in track 1. Also in track 2 and 3 and so on....
Frank
Re: SDHxC to emulate a IBM3740 Format?
Frank wrote:Hi Jeff,
the shorting of the pulswide is working now over a 74LS123 up to about 450ns.
I am now able to read the contents from a "empty disk", created with the right parameters (all tracks, all sectors).
When i export the BB1.imd over "LOAD" and the export it to the SD-card, then i am only able to read track 0.
With the right parameters and "LOAD RAW" the BB1.imd and then export to SD-card, i am able to read all tracks with the right content.
Is there a way to convert the *.imd files to a *.raw file?
Frank
PS:The file BBCPM.IMD is not loadable in the software, why? Creating a real disk with IMD.COM has no problem with the BBCPM.IMD.
First it's good to see that you managed to get working the emulator.
Just change the file header to "IMD 1.07:".Frank wrote: PS:The file BBCPM.IMD is not loadable in the software, why? Creating a real disk with IMD.COM has no problem with the BBCPM.IMD.
yes : export them the img file format.Frank wrote: Is there a way to convert the *.imd files to a *.raw file?
Re: SDHxC to emulate a IBM3740 Format?
mhh i don't reproduce the issue here. Have you the last software ?Frank wrote:When i "reimport" the BB1_IMD.hfe in the new 2.xx HxC-Software and look on the datas in the sectors,
they are indentically in track 0 and in track 1. Also in track 2 and 3 and so on....
Frank
Do you have activated the double step mode ? You shouldn't do this for this system.