the controller and fat probably are not.. they were designed before that disk size was available..
On Sun, Mar 24, 2019 at 6:32 PM Stephen Adolph <twospru...@gmail.com> wrote: > interestingly, > > Yes, if I take an HD disk, and tape over the hole to make it appear to be > a DD disk, then it works. > > But why? > > the floppy is capable of both formats... > > On Sun, Mar 24, 2019 at 7:39 PM Mike Stein <mhs.st...@gmail.com> wrote: > >> Have you tried closing the HD sense hole with a piece of tape or similar? >> >> ----- Original Message ----- >> *From:* Stephen Adolph <twospru...@gmail.com> >> *To:* m...@bitchin100.com >> *Sent:* Sunday, March 24, 2019 6:08 PM >> *Subject:* Re: [M100] question regarding floppy disks. >> >> the Coco is using it's standard controller >> >> When issuing the DSKINI 0 command the coco tries to format for 180kB. >> >> The combination of >> (Coco, std controller, PC 1.44MB drive + a 720kB dd floppy) works >> >> whereas >> (Coco, std controller, PC 1.44MB drive + a 1.44MBB hd floppy) does not >> work >> >> this is something I don't understand! >> >> >> >> On Sun, Mar 24, 2019 at 5:42 PM Gregory McGill <arcadeshop...@gmail.com> >> wrote: >> >>> likely the floppy controller doesn't support 80 tracks or high >>> density.. most of the controllers of the era are ds/sd 40 track or dsdd 40 >>> track.. are you able to format 720k? ds/dd 80 track? >>> >>> Greg >>> >>> On Sun, Mar 24, 2019 at 2:38 PM Stephen Adolph <twospru...@gmail.com> >>> wrote: >>> >>>> I'll start by saying this isn't an M100 or TPDD discussion, but just >>>> looking to understand something. >>>> >>>> I have a Tandy Coco3 with a 3.5 inch floppy drive. The drive is a >>>> standard PC drive and it is working well. >>>> >>>> Seems though that I cannot use 1.44 MB floppies in that drive. They >>>> don't seem to want to format. >>>> >>>> I really don't understand where the problem could be. >>>> - the drive and the floppy are compatible >>>> - the disk is known good and formats at 1.44MB in a PC >>>> - if it can support 135 TPI, why can't it support 35 TPI? >>>> >>>> Does anyone know what's going on? >>>> >>>> thx >>>> Steve >>>> >>>
