+Nezgar Posted December 30, 2020 Share Posted December 30, 2020 4 hours ago, EddyFree said: OK, that makes sense. So that would mean a double-density drive should be able to read the first 720 sectors of an enhanced density disk? What I'm wondering is what causes most of the Truncated enhanced density disk images I come across. I know it can easily be disk copiers that don't read passed sector 720, but was wondering if it could be a hardware situation also. Well - yes - "technically" a double density drive could read an enhanced density disk, but it requires firmware support... Good examples would be 3rd party double-density drives like Percom, Rana, Trak - they do not support enhanced density, but technically could if someone were to update their firmware. As for ED disk images with only 720 sectors... Yes it could be either the person used a suboptimal sector copier, or maybe used an SIO2PC type software with only 720 sector ATR blank disk templates or something... I've also seen the reverse - ED ATR's with less than 720 sectors in use... Since the 1050 does not use the "Percom" standard to query disk density, software must have extra logic to check the drive status command for the FM/MFM flag to tell the difference between an SD or ED disk... There was also an "early" US Doubler ROM that incorrectly reported the STATUS command for an ED disk, so there's a remote chance the archivist had this ROM in their 1050, albeit quite remote: https://atariage.com/forums/topic/298026-us-doubler-rom/?do=findComment&comment=4385410 1 Quote Link to comment Share on other sites More sharing options...
Gunstar Posted December 30, 2020 Share Posted December 30, 2020 (edited) Indus GT's and clones do support 1050 enhanced density, most of the time, I do have a few games that won't work on them and require a real 1050 (a recent one to me that I discovered, Fountain Of The Gods with the dungeon disk side B from Atarimania, in 1050 enhanced density). But usually, as long as I write the floppies from ATR images on my Indus GT's and CA-2001 drives in enhanced density using Atarimax APE Prosystem with Indus GT compatibility turned on, they work fine. Indus GT's detect disk density and will show on the digital display 1A, 1B or 1C (single, double and enhanced respectively) or 2A etc. with multiple drives. Edited December 30, 2020 by Gunstar 1 Quote Link to comment Share on other sites More sharing options...
MrMartian Posted December 31, 2020 Share Posted December 31, 2020 On 12/30/2020 at 12:41 AM, Nezgar said: Well - yes - "technically" a double density drive could read an enhanced density disk, but it requires firmware support... Good examples would be 3rd party double-density drives like Percom, Rana, Trak - they do not support enhanced density, but technically could if someone were to update their firmware. As for ED disk images with only 720 sectors... Yes it could be either the person used a suboptimal sector copier, or maybe used an SIO2PC type software with only 720 sector ATR blank disk templates or something... I've also seen the reverse - ED ATR's with less than 720 sectors in use... Since the 1050 does not use the "Percom" standard to query disk density, software must have extra logic to check the drive status command for the FM/MFM flag to tell the difference between an SD or ED disk... There was also an "early" US Doubler ROM that incorrectly reported the STATUS command for an ED disk, so there's a remote chance the archivist had this ROM in their 1050, albeit quite remote: https://atariage.com/forums/topic/298026-us-doubler-rom/?do=findComment&comment=4385410 Any of my updated firmwares for the Trak or Rana support enhanced density in addition to ultrapseed. Percom I would like to do as well as the ATR8000. 1 Quote Link to comment Share on other sites More sharing options...
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