3.5" Drive for the Atari 8bit computer

[@flashjazzcat]

U1MB owners using the firmware shown in the video: please use the high-speed SIO driver built into the BIOS. There's no need to use the high-speed patched OS with any operating system which supports PBI device handlers. ;)

[@WareWolf801]

Love that intro music! Sounds like something I would have heard on a "menu disk" from my Atari ST's, back in the day.

[@kamiltrzaska]

Hi Nir, that's really a convenient way of storing software

[@retrogamer1]

Great job! Now make it happen with a SF 314 or SF 324, would look fantastic next to a 130XE. :) Thanks for sharing this video :)

[@zaxoniec]

Well, i can redesign board, will fit in to SF drive, no big deal ;) Big deal is buy SF drive ;)

[@MessalineApghar]

@@zaxoniec i would buy 2 of the SF conversion boards

[@SeñorDossierOficial]

That drive looks great

[@KuraIthys]

Nice... I've been thinking through how to get USB storage devices hooked up to the SIO port. You might ask what that has to do with the video, but the point is that the easiest way to obtain a 3.5 inch floppy drive at the moment is to get hold of a USB drive. They cost like $10-15 new. So if you could figure out how to get one of those working with an Atari, that would work wonders. (as a side effect you could likely also get USB flash drives working, since the logic for how that works is very similar either way. - although the formatting would be different.) Still, this is a nice solution too... Plus this exists. My concept is pure theory. XD

[@larryw1815]

You mentioned that 720K or 1.44 MB disks can be used. Is the disk sensing mechanism "smart" so that it changes the write current for the 1.44? Also, is the disk format for double side compatible with XF551 modded (track 1-80 on side A, then 81-160 on side B? The other possibility is that the drive alternates sides for every track 1 (A-B), 2 (A-B), ... 80 (A-B). That is an issue if you already have a bunch of 3-1/2" disks.

[@TheModernAtari8bitcomputer]

even if you use a 1.44mb 3.5" floppy you can format it for 720k max, so 80 tracks 9 sectors (double sided per track)

[@KuraIthys]

Does that mean it's impossible to format a disk as an actual 1.44 megabyte HD disk? I have some game dev stuff I'm vaguely working on (all early concept stuff), and some of it is standard atari stuff, but some of it is for the VBXE which needs a lot more storage space to use effectively. Obviously it's a moot point unless a lot of people have 3.5 inch drives, but I figured it'd be the perfect 'authentic' companion to a system with a VBXE + Rapidus setup, and would be more practical for games/programs that actually run on such a system. I can simulate a 1.44 megabyte disk using SIOtoUSB and AspeQt, but it doesn't seem like any existing OS can really make sense of that. And even if it could, I'm curious if a disk drive like this can support it? I have a really large supply of HD 3.5 inch disks (mostly formatted for PC, and dating to the 90's), but basically no 5.25 inch disks at all. So being able to use them for something is useful in itself, but... it'd be nice if using the full capacity was an actual option...

[@TheModernAtari8bitcomputer]

@@KuraIthys the Drive pcb support 720k max

[@KuraIthys]

That's unfortunate. Understandable, but... Unfortunate. Oh well. It's a lot better than nothing at all.

[@RyanGoolevitch]

@@TheModernAtari8bitcomputer 18 256 byte sectors per track in this case. An ST or DOS disk would be formatted as 9 512 byte sectors per track.

[@Miesiu]

What about the sector size ? On the classic double density - 180KB - the sector was 256 bytes but the first 3 sectors was always 128 bytes. What about the full capacity ? Tracks ? Sectors per track ? 1 / 2 side (s) ? Even for Atari ST the first floppy was the only 360KB 'cos 1 side. What is speed ? Turbo like Synchromesh or what ?

[@RyanGoolevitch]

18 256 byte sectors per track, just like normal Atari double density. The first 3 sectors of track 0 are still 128 bytes - however they are still physically 256 byte sectors on the disk. (This is true for double density on 5.25" disks). The 720K mode is merely 80 tracks instead of 40, and 2 sides... so technically 160 tracks of 18 256byte sectors each with the maximum single disk format. (256x18x160=737280 bytes, divide by 1024 = 720KiB)

[@Miesiu]

THX

[@tschak909]

sounds like the sector order needs optimizing.

[@brianwild4640]

Does anyone know how to emulate the spata dos pass through cart with another cart in an emulator please

[@mchorvat]

looks awesome! does it work with SpartaDos X?

[@TheModernAtari8bitcomputer]

Yes, you can use Spartados

[@Gitbizy]

Where can I buy one of these?

[@alleynecostin6709]

i would like one also. did you ever get one?

[@Gitbizy]

@@alleynecostin6709 yes I bought one and it’s a very nice unit.

[@monetize_this8330]

Not as useful as I had hoped. 720K disks are worse for shedding oxide. (so more likely to require regular head cleaning)

[@zaxoniec]

You can use 1.44 discs without problem.

[@silvanopetralia5928]

Salve ma questo drive dove si può trovare?

[@tjlazer71]

Can't you just connect this to a 1050 as drive 2 and copy to it from the 1050?

[@almerian]

Yes.

[@euskaldunakotxoan9075]

very nice, if these are for sale, can you post a link ? thanks !!

[@zaxoniec]

Next units is under construction will be soon on Sell my retro, www.sellmyretro.com/offer/details/37199 .Sorry, is not cheap but all drives is 100% handmade by me what take some time = money.

[@KuraIthys]

I've seen much worse prices for atari accessories like this, so I'm not about to complain. I'd prefer if it could format HD disks to use the full 1.44 megabyte capacity, but it's a miracle as it is... Really been thinking about something like this for quite a while, so I'm glad to see someone has gone through the effort of making one, even if it isn't 100% what I would've hoped for...

[@RyanGoolevitch]

@@KuraIthys This has been available as a mod for the Atari XF551 since at least 1998. New firmware to recognize 80 tracks, at 38400 bps highspeed like the XF551, and later enhanced to do UltraSpeed like the US Doubler (54000bps). The nice thing about this drive is that it's an entirely new PCB design that uses modern components, and does not require modifying an existing XF551. There are a number of components on the original XF551 controller board that are no longer available, which makes directly cloning the original PCB a challenge. 1.44MB is possible, but noone has designed a firmware that would support it, and noone has designed a new PCB to host such a controller chip. Chicken/Egg situation. Well, there was one exception - the CSS Floppy Board, which was an add-on to an already expensive and rare PBI based hard drive controller from the late 80's.

[@KuraIthys]

Mmh. I kind of figured there'd be a reason behind it. I'm unfamiliar with the XF551 (I did just look it up though), so I'm a little unclear as to why 3.5 inch drives would be based on it. But it's certainly interesting that mods like that have existed for so long. To fair I only got an Atari again last year, and I last owned them around 1992 - and even back then I didn't own disk drives of any kind. (I now have a 1050 with no power supply, which is a moot point because I have no 5.25 inch disks anyway. - but since it was included in the lot I bought... I'll have to check if it even works I guess.) There was of course the official Atari 3.5 inch drive, but that never got past being a prototype AFAIK (and would've been a DD 720k drive anyway.) I guess it's quite a leap designing an entirely new design of disk controller - even though this unit, since it's based on new components rather than being a modification, presumably is using a standard PC drive mechanism - I can't imagine much else is available new these days. I'm honestly even surprised that those are still for sale, since All I've seen available going on about the last decade have been cheap USB floppy drives... I suspect that might still be an easier route to getting a 1.44 megabyte drive in the long run. Creating a USB host contoller for SIO, and some built-in logic to read USB storage devices, and handle FAT 12 and FAT 16 formatting (at a minimum) inside the USB interface device, rather than getting the atari to deal with it. Wouldn't be particularly compatible with existing software though...

[@markstrickland438]

@@zaxoniec These are cheaper than I thought they would be. I've wanted a 3.5" floppy since reading about the XF551 mod 20 years ago, but didn't want to hack up my XF551. Will you be making any more of these? Can you ship to the United States?

[@nasty_niff]

Hi nir, what the speed like compared to 1050 with mods?

[@TheModernAtari8bitcomputer]

fast if not faster then that HAPPY with the HIGH SPEED OS routines

[@RyanGoolevitch]

@@TheModernAtari8bitcomputer But no track buffer. So a disk formatted with the highspeed skew will read slower than normal speed without the highspeed OS...