ebiguy Posted July 7, 2016 Share Posted July 7, 2016 Reading the 1771 floppy disk controller documentation, i see that this chip can handle both 5 1/4 and 8 inch floppy drives. I was wondering if anyone ever had the "crazy" idea of connecting an 8 inch floppy drives ? Note that it seems that 8 inch drives need a 2MHz clock (not the 1MHz found in the 810) in order to work. Quote Link to comment Share on other sites More sharing options...
COBRAIP Posted July 7, 2016 Share Posted July 7, 2016 If you have an ATR8000 then you have not problem. I had 4 8 inch floppy drives in a box 1/2 height stacked hooked to the 8000 and it ran fine. This was all hooked to a 130XE out to an MIO 1Meg and to the ATR. Also had 2 hard drives in a case being run at the same time. This accounted for 6 drives and that left me with 2 and the MIO counted as one and now all I had left was the 1050. It was a nice setup to run an Oasis BBS. I ran it for 2 years and then shut it down. 3 Quote Link to comment Share on other sites More sharing options...
Kyle22 Posted July 9, 2016 Share Posted July 9, 2016 SDX supports 8 inch drives. Quote Link to comment Share on other sites More sharing options...
Muzz73 Posted July 9, 2016 Share Posted July 9, 2016 I don't know the exact setup, but the Temple of Zuul (BBS in my local calling area when I was a teenager) ran on an A8 of some sort with two 8" floppy drives, if memory serves me... and that's a big "if"! Quote Link to comment Share on other sites More sharing options...
walter_J64bit Posted July 9, 2016 Share Posted July 9, 2016 How many kilobyte of data can an 8" floppy hold? Quote Link to comment Share on other sites More sharing options...
Joey Z Posted July 9, 2016 Share Posted July 9, 2016 (edited) How many kilobyte of data can an 8" floppy hold? well, when formatted on the ATR-8000, I think it was about 1MB it really depends what computer you use it on though, and particularly what sector size you use. 8" disks are 77 track and operate at the same data rate and rotational velocity as a 5.25" 1.2MB floppy. So in theory, they can do the same number of 512 byte sectors per track, though with 3 less tracks. A 5.25" 1.2MB drive normally is formatted with 15 sectors per track, 512 bytes/sector. At 77 tracks, and the same formatting otherwise, an 8" disk would hold 1182720 bytes (1155KB). An 80 track 5.25" HD drive formatted in the same way with 80 tracks would hold 1200KB. When formatted for Atari usage, it will often be 256 or 128 bytes per sector, meaning the drive will have more sectors per track, but also more wasted space in gaps between sectors. IIRC, like I said, I think the ATR-8000 (at 256 bytes/sector IIRC) got about 1MB out of them. Edited July 9, 2016 by Joey Z Quote Link to comment Share on other sites More sharing options...
Mathy Posted July 9, 2016 Share Posted July 9, 2016 Hello guys MyDOS supports 8" drives too. Sincerely Mathy Quote Link to comment Share on other sites More sharing options...
Kyle22 Posted July 10, 2016 Share Posted July 10, 2016 Yes, it does, but SDX is a professional OS that supports the widest range of hardware, including Corvus drives. Can MyDOS do that? Quote Link to comment Share on other sites More sharing options...
+Stephen Posted July 10, 2016 Share Posted July 10, 2016 4 Quote Link to comment Share on other sites More sharing options...
+Larry Posted July 10, 2016 Share Posted July 10, 2016 Is a Corvus a brand of 8" floppy drive? - Larry 1 Quote Link to comment Share on other sites More sharing options...
+Stephen Posted July 10, 2016 Share Posted July 10, 2016 Is a Corvus a brand of 8" floppy drive? - Larry Far as I know, it was the first HD for the Ataris, connected via joystick ports, worked on the 800. 1 Quote Link to comment Share on other sites More sharing options...
kogden Posted July 12, 2016 Share Posted July 12, 2016 (edited) Yes, it does, but SDX is a professional OS that supports the widest range of hardware, including Corvus drives. Can MyDOS do that? MyDOS also supports a ton of hardware, can be booted straight from disk instead of ROM, works like a standard Atari DOS, is actually *usable* with only 48K of RAM, and has source code available to the public.... Can SDX do THAT? Both have their place. Both support 8" floppies and other weird goodies. Corvus support also existed in a mutant version of Atari DOS from Corvus and is probably useful to 3 people out there that have Corvus HDD setups. There's probably a lot more people with PBI IDE/SCSI interfaces than Corvus ever dreamt of selling. Edited July 12, 2016 by kogden 1 Quote Link to comment Share on other sites More sharing options...
Crimefighter Posted July 12, 2016 Share Posted July 12, 2016 At this point I'd use the 3.5" drives... Quote Link to comment Share on other sites More sharing options...
ebiguy Posted July 12, 2016 Author Share Posted July 12, 2016 Ok, there is the ATR8000 but I was thinking about a "custom made" hack of an existing drive or something similar. For example disconnecting the drive of the 1050 and use the remaining board connected to an 8 inch drive. If I find a spare 8 inch drive, is it possible to connect it without an ATR800 to an Atari system ? Quote Link to comment Share on other sites More sharing options...
+Larry Posted July 12, 2016 Share Posted July 12, 2016 You are aware just how big these 8" beasts are? If by chance you've never seen one "up close and personal" they are truly HUGE. There are some good images of these at https://en.wikipedia.org/wiki/Floppy_disk A 720K/1.44 drive in an XF551 seems a bit more logical. OTOH, if you're determined, the 8" floppy might well work with a Percom Controller board. -Larry Quote Link to comment Share on other sites More sharing options...
ebiguy Posted July 12, 2016 Author Share Posted July 12, 2016 If I was considering the space, the logic for the Atari would be to use no physical drvie but an SIO2SD which is really smaller and can even be embedded in the Atari case. If I was logic I would put the Atari in the attic or on eBay to use only a PC, a Mac or a tablet. But hopefully, logic is not driving me (us ?) in my hobbies. Of course this is a stupid or crazy idea but that's what is fun... But thank you for the warning ! More seriously, I will probably never buy an 8" drive but this would be an interesting project for someone having electronic knowledge. See this as a way to use vintage devices with your Atari. Why not thinking of adding an SIO interface to connect punch card reader (or does it already exist ?) Could be interesting to have cards in the future expansion box designed by Dropcheck for interfacing both moderm devices and very old devices part of the history. 2 Quote Link to comment Share on other sites More sharing options...
Beetle Posted July 12, 2016 Share Posted July 12, 2016 In fact i own an 8" Floppy drive as well as a handful of floppy disks for it. Most are Singlesided, Single Density, but two are DSDD, the desired 1M formatted size. Once i wanted to hook it up to the black box. If one has a good idea how to connect it to an Atari, lets continue,no matter it makes sense or not. 1 Quote Link to comment Share on other sites More sharing options...
AtariGeezer Posted July 12, 2016 Share Posted July 12, 2016 Isn't it possible to hang an 8 inch drive off the extender port on some of the Percom drives? 1 Quote Link to comment Share on other sites More sharing options...
Beetle Posted July 12, 2016 Share Posted July 12, 2016 AFAIK my drive has some unusual pinout that is almost compatible to the shugart bus, but will not connect directly to a PC floppy cable It also needs 24V, 12V and 5V power supply. Will try to gain more info. Quote Link to comment Share on other sites More sharing options...
ebiguy Posted July 12, 2016 Author Share Posted July 12, 2016 What is the model number ? Any pictures ? Quote Link to comment Share on other sites More sharing options...
+Stephen Posted July 12, 2016 Share Posted July 12, 2016 AFAIK my drive has some unusual pinout that is almost compatible to the shugart bus, but will not connect directly to a PC floppy cable It also needs 24V, 12V and 5V power supply. Will try to gain more info. Wow - does it dim the lights when powering on? I wish I had some older floppy equipment such as that. My oldest drive is a 1050. Quote Link to comment Share on other sites More sharing options...
Kyle22 Posted July 13, 2016 Share Posted July 13, 2016 You can make a 50 to 34 pin adapter to connect the 8" drive to the controller. http://www.classiccmp.org/dunfield/img54306/cnct.htm 1 Quote Link to comment Share on other sites More sharing options...
walter_J64bit Posted July 13, 2016 Share Posted July 13, 2016 You are aware just how big these 8" beasts are? If by chance you've never seen one "up close and personal" they are truly HUGE. There are some good images of these at https://en.wikipedia.org/wiki/Floppy_disk A 720K/1.44 drive in an XF551 seems a bit more logical. OTOH, if you're determined, the 8" floppy might well work with a Percom Controller board. -Larry I've seen one back in the 80's at my school, it was for library what they was using for I don't know but when seen the disk get pulled from that monster of disk drive I was like a deer in headlights! Quote Link to comment Share on other sites More sharing options...
Joey Z Posted July 13, 2016 Share Posted July 13, 2016 AFAIK my drive has some unusual pinout that is almost compatible to the shugart bus, but will not connect directly to a PC floppy cable It also needs 24V, 12V and 5V power supply. Will try to gain more info. the old 8" drives had synchronous mains voltage motors in them, often requiring a 120/240VAC supply, and being region specific to 50/60hz. it's possible yours is different though. Quote Link to comment Share on other sites More sharing options...
kogden Posted July 14, 2016 Share Posted July 14, 2016 The 8" drives are beastly.... only machines I ever really saw them on in person were DEC minis, some Convergent Tech machines and very old CP/M machines. Media is probably incredibly expensive as well now. Even 5.25" DSDD disks are pricey now. A modified Percom or an ATR8000 is probably the best bet. Even if you were able to wire it up to a 1050 controller, I would assume you would have to write some custom firmware as well to really utilize it. I'd rather have a 3.5" drive personally. I can get free media for that all day long. I can't spend $5-$10 per disk and $300 for a working 8" floppy drive. If I could, I'd build an S-100 crate and use it there instead. 1 Quote Link to comment Share on other sites More sharing options...
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