Hard sector format

HxC Floppy emulator support for all others computers...
Post Reply
snhirsch
Posts: 170
Joined: Tue Dec 08, 2015 1:42 am

Re: Hard sector format

Post by snhirsch »

I'm pleased to say that decoding of KF captures is working properly for Northstar images. Here's how I tested it:
  • Start with known good Northstar DS floppy having data that extends to side 1
  • Capture raw file using Kryoflux Beta software
  • Convert to NSI image using HxCFloppyEmulator software
  • Capture sector image of floppy using FC5025 device and save as NSI
  • Checksum both image files
They compare exactly, so I think we can have a high degree of confidence in your decoding :-).

You can disregard my concerns about missing data on side 1. I managed to get diskettes mixed up here and the previous floppy was empty on the second side. For today's test I made sure to use a diskette that was > 50% full.

Note: I re-checked the results from the FC5025 device and I'm still seeing a +2 physical skew in sector location. It makes no sense that Northstar would be using a 1:1 skew since controllers and host computers of that era were not fast enough to read a non-interleaved diskette without wasting rotational time. The FC5025 reads the entire track at once and does decode sectors, so I tend to believe what it's telling me. Once you get the Gotek firmware fully operational I'll run some read benchmarks against a real floppy. It should be very obvious if the emulator is using a non-optimal skew.

Let me know when you have a version of HxCFloppyEmulator that can decode Heath diskettes and I will try the same test on those.

Jeff
Site Admin
Posts: 8092
Joined: Fri Oct 20, 2006 12:12 am
Location: Paris
Contact:

Re: Hard sector format

Post by Jeff »

snhirsch wrote:
Sat May 26, 2018 3:16 pm
Note: I re-checked the results from the FC5025 device and I'm still seeing a +2 physical skew in sector location. It makes no sense that Northstar would be using a 1:1 skew since controllers and host computers of that era were not fast enough to read a non-interleaved diskette without wasting rotational time. The FC5025 reads the entire track at once and does decode sectors, so I tend to believe what it's telling me. Once you get the Gotek firmware fully operational I'll run some read benchmarks against a real floppy. It should be very obvious if the emulator is using a non-optimal skew.
What you can see in the hxc track/disk viewer is exactly what you have on the disk surface. There is no sector change/reorder done by the hxc software during the kf importation ! I am 100% sure that there is no interleave and no skew in the Northstar dumps you sent me.

Jeff
Site Admin
Posts: 8092
Joined: Fri Oct 20, 2006 12:12 am
Location: Paris
Contact:

Re: Hard sector format

Post by Jeff »

New version with heathkit h8d import/export support :

https://hxc2001.com/download/floppy_driv ... t_beta.zip

Jeff
Site Admin
Posts: 8092
Joined: Fri Oct 20, 2006 12:12 am
Location: Paris
Contact:

Re: Hard sector format

Post by Jeff »

And about the emulation :

https://hxc2001.com/download/floppy_driv ... rmware.zip

Let me know if the alpha version is helping with the northstar (the UPD to use is in the "Next_WIP_Alpha_Firmware_And_Tools" folder).

snhirsch
Posts: 170
Joined: Tue Dec 08, 2015 1:42 am

Re: Hard sector format

Post by snhirsch »

Jeff wrote:
Sat May 26, 2018 10:16 pm
snhirsch wrote:
Sat May 26, 2018 3:16 pm
Note: I re-checked the results from the FC5025 device and I'm still seeing a +2 physical skew in sector location. It makes no sense that Northstar would be using a 1:1 skew since controllers and host computers of that era were not fast enough to read a non-interleaved diskette without wasting rotational time. The FC5025 reads the entire track at once and does decode sectors, so I tend to believe what it's telling me. Once you get the Gotek firmware fully operational I'll run some read benchmarks against a real floppy. It should be very obvious if the emulator is using a non-optimal skew.
What you can see in the hxc track/disk viewer is exactly what you have on the disk surface. There is no sector change/reorder done by the hxc software during the kf importation ! I am 100% sure that there is no interleave and no skew in the Northstar dumps you sent me.
Very, very strange. No computer of that age should be optimal with 1:1 interleave. You've seen many old diskette layouts. Is 1:1 on a 40 year old machine common in your experience?

I will ask Adam (developer of FC5025) to comment on what I'm seeing in its diagnostic messages.

snhirsch
Posts: 170
Joined: Tue Dec 08, 2015 1:42 am

Re: Hard sector format

Post by snhirsch »

Hi, Jeff. Just uploaded two tarballs to your ftp site. Some issues with conversion of KF streams from Heath.

I'll try the firmware next.

snhirsch
Posts: 170
Joined: Tue Dec 08, 2015 1:42 am

Re: Hard sector format

Post by snhirsch »

Not much luck with new firmware on Northstar emulation. Many more errors - all "NO INDEX PULSE".

Jeff
Site Admin
Posts: 8092
Joined: Fri Oct 20, 2006 12:12 am
Location: Paris
Contact:

Re: Hard sector format

Post by Jeff »

snhirsch wrote:
Sun May 27, 2018 5:17 pm
Jeff wrote:
Sat May 26, 2018 10:16 pm
snhirsch wrote:
Sat May 26, 2018 3:16 pm
Note: I re-checked the results from the FC5025 device and I'm still seeing a +2 physical skew in sector location. It makes no sense that Northstar would be using a 1:1 skew since controllers and host computers of that era were not fast enough to read a non-interleaved diskette without wasting rotational time. The FC5025 reads the entire track at once and does decode sectors, so I tend to believe what it's telling me. Once you get the Gotek firmware fully operational I'll run some read benchmarks against a real floppy. It should be very obvious if the emulator is using a non-optimal skew.
What you can see in the hxc track/disk viewer is exactly what you have on the disk surface. There is no sector change/reorder done by the hxc software during the kf importation ! I am 100% sure that there is no interleave and no skew in the Northstar dumps you sent me.
Very, very strange. No computer of that age should be optimal with 1:1 interleave. You've seen many old diskette layouts. Is 1:1 on a 40 year old machine common in your experience?

I will ask Adam (developer of FC5025) to comment on what I'm seeing in its diagnostic messages.
Yes this is common.
Anyway for sure there is no interleave in the present case.

Jeff
Site Admin
Posts: 8092
Joined: Fri Oct 20, 2006 12:12 am
Location: Paris
Contact:

Re: Hard sector format

Post by Jeff »

snhirsch wrote:
Sun May 27, 2018 6:03 pm
Not much luck with new firmware on Northstar emulation. Many more errors - all "NO INDEX PULSE".
Many more ? more than with the previous firmware version ?
How did you test the firmware (with which images and how did you create these images ?)

snhirsch
Posts: 170
Joined: Tue Dec 08, 2015 1:42 am

Re: Hard sector format

Post by snhirsch »

Jeff wrote:
Sun May 27, 2018 6:19 pm
snhirsch wrote:
Sun May 27, 2018 6:03 pm
Not much luck with new firmware on Northstar emulation. Many more errors - all "NO INDEX PULSE".
Many more ? more than with the previous firmware version ?
How did you test the firmware (with which images and how did you create these images ?)
Yes, more than with the previous firmware. I tested with a converted KF image and one created from an NSI file (FC5025 capture).

Jeff
Site Admin
Posts: 8092
Joined: Fri Oct 20, 2006 12:12 am
Location: Paris
Contact:

Re: Hard sector format

Post by Jeff »

snhirsch wrote:
Sun May 27, 2018 6:36 pm
Jeff wrote:
Sun May 27, 2018 6:19 pm
snhirsch wrote:
Sun May 27, 2018 6:03 pm
Not much luck with new firmware on Northstar emulation. Many more errors - all "NO INDEX PULSE".
Many more ? more than with the previous firmware version ?
How did you test the firmware (with which images and how did you create these images ?)
Yes, more than with the previous firmware. I tested with a converted KF image and one created from an NSI file (FC5025 capture).
Ok so this probably mean that the current nominal index position is not the right one. the newer firmware have a better index jitter behaviour and should have less error... The good news is that i can now make a dump of the "hard sectored" emulator ;).

Jeff
Site Admin
Posts: 8092
Joined: Fri Oct 20, 2006 12:12 am
Location: Paris
Contact:

Re: Hard sector format

Post by Jeff »

snhirsch wrote:
Sun May 27, 2018 5:55 pm
Hi, Jeff. Just uploaded two tarballs to your ftp site. Some issues with conversion of KF streams from Heath.

I'll try the firmware next.

software updated to fix these cases :

https://hxc2001.com/download/floppy_driv ... t_beta.zip

should be better now :D

snhirsch
Posts: 170
Joined: Tue Dec 08, 2015 1:42 am

Re: Hard sector format

Post by snhirsch »

Jeff wrote:
Sun May 27, 2018 7:19 pm
snhirsch wrote:
Sun May 27, 2018 5:55 pm
Hi, Jeff. Just uploaded two tarballs to your ftp site. Some issues with conversion of KF streams from Heath.

I'll try the firmware next.

software updated to fix these cases :

https://hxc2001.com/download/floppy_driv ... t_beta.zip

should be better now :D
Yes, that's got it! Both images compare 100% with FC5025 sector data. Should I try Heath emulation on Gotek, or is that still being worked on?

Jeff
Site Admin
Posts: 8092
Joined: Fri Oct 20, 2006 12:12 am
Location: Paris
Contact:

Re: Hard sector format

Post by Jeff »

snhirsch wrote:
Sun May 27, 2018 7:58 pm
Yes, that's got it! Both images compare 100% with FC5025 sector data. Should I try Heath emulation on Gotek, or is that still being worked on?
yes you can try the gotek with the heath. you may need to try the alpha and the current firmware version.

snhirsch
Posts: 170
Joined: Tue Dec 08, 2015 1:42 am

Re: Hard sector format

Post by snhirsch »

Heath emulation on the Gotek is working!! I was able to copy all the files from a mostly full diskette image with no errors :-).

If you have any updates to help with the Northstar issues, let me know and I'll try them.

Post Reply