Post by thread:[PIC]: Floppy storage

I've got a product using an 18c452 with 128 kbytes of external static RAM. I'd like to add low cost removable storage, and the 3.5 inch floppy seems ideal. The drives are incredibly cheap, and so is the media. I've included a National FDC chip on the board, but have not as yet looked at writing any code for it. In this application, I'm looking at saving and loading an ascii text file to/from the disk. To keep costs down and operation simple, we have no display on the product, so the operator just hits a button to load a file from the disk and another button to save it (with some precautions to make sure current data in RAM or on disk is not accidentally wiped out). I'm thinking of using PC format with a fixed filename, again further simplifying it. There would be no way to format a disk, delete the file, etc. Just load and store. Has anyone done anything like this? Another approach I'm considering is making a very small embedded 80x6 system that is a FD to EIA232 interface. Then I could use something like DataLight's ROM-DOS and have most of the code already written. I did something like this years and years ago. There I did a 6802 system and wrote code to talk to a Commodore 1541 disk drive. On the 6802 system you could save and load applications programs, do a directory of the floppy, format floppies, etc. Again, the goal there was to try to not have to write an operating system, so I used Commodore's. So... Floppies, anyone? Harold FCC Rules Online at http://www.hallikainen.com/FccRules/ ________________________________________________________________ YOU'RE PAYING TOO MUCH FOR THE INTERNET! Juno now offers FREE Internet Access! Try it today - there's no risk! For your FREE software, visit: dl.http://www.juno.com/get/tagj. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

I think Compact Flash is a much better solution these days. Higher capacity, smaller size, lower power, NO MOVING PARTS, PC-compatible. Did I forget anything? Andy Harold Hallikainen <spam_OUTharoldhallikainenTakeThisOuTJUNO.COM> on 10/11/2000 12:17:17 AM Please respond to pic microcontroller discussion list <.....PICLISTKILLspam@spam@MITVMA.MIT.EDU> To: PICLISTKILLspamMITVMA.MIT.EDU cc: (bcc: Andrew Kunz/TDI_NOTES) Subject: Re: [PIC]: Floppy storage I've got a product using an 18c452 with 128 kbytes of external static RAM. I'd like to add low cost removable storage, and the 3.5 inch floppy seems ideal. The drives are incredibly cheap, and so is the media. I've included a National FDC chip on the board, but have not as yet looked at writing any code for it. In this application, I'm looking at saving and loading an ascii text file to/from the disk. To keep costs down and operation simple, we have no display on the product, so the operator just hits a button to load a file from the disk and another button to save it (with some precautions to make sure current data in RAM or on disk is not accidentally wiped out). I'm thinking of using PC format with a fixed filename, again further simplifying it. There would be no way to format a disk, delete the file, etc. Just load and store. Has anyone done anything like this? Another approach I'm considering is making a very small embedded 80x6 system that is a FD to EIA232 interface. Then I could use something like DataLight's ROM-DOS and have most of the code already written. I did something like this years and years ago. There I did a 6802 system and wrote code to talk to a Commodore 1541 disk drive. On the 6802 system you could save and load applications programs, do a directory of the floppy, format floppies, etc. Again, the goal there was to try to not have to write an operating system, so I used Commodore's. So... Floppies, anyone? Harold FCC Rules Online at http://www.hallikainen.com/FccRules/ ________________________________________________________________ YOU'RE PAYING TOO MUCH FOR THE INTERNET! Juno now offers FREE Internet Access! Try it today - there's no risk! For your FREE software, visit: dl.http://www.juno.com/get/tagj. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

>I think Compact Flash is a much better solution these days. Higher capacity, >smaller size, lower power, NO MOVING PARTS, PC-compatible. > >Did I forget anything? > >Andy Floppy disk A dying technology but still has a way to go before it lies down and dies. Yes - we all know Floppy's problems, but - Zero (almost) cost per media. Media available everywhere (even service stations, drug stores etc in NZ) Store xxx of them if desired. Compatible readers/writers eeeeverywhere. Mail one to someone and they will know what to do with it (reformat it in their Mac :-) (by no means all PCs yet have compact flash readers) RM -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

No one, to my knowledge, has interfaced a floppy to a PIC/and/ implemented a DOS file system on it. I've only heard of people interfacing to floppies, but haven't seen any actual code or schematics. Interfacing and controlling the floppy with the national chip should be fairly easy, the real work comes when you try to use your PIC to understand the file system on the disk. I notice you are trying to make it easier for the PIC by limiting the amount of work it has to do (create the file, etc) but you will have to create the file somewhere, and the will likely require a seperate computer and program that understands the low-level details of the floppy and tailers the file location for you. However, file system code is relatively easy to get, you would find such code in the various free software projects (FreeBSD, Linux, etc). -Adam Harold Hallikainen wrote: {Quote hidden}> > I've got a product using an 18c452 with 128 kbytes of external static > RAM. I'd like to add low cost removable storage, and the 3.5 inch floppy > seems ideal. The drives are incredibly cheap, and so is the media. I've > included a National FDC chip on the board, but have not as yet looked at > writing any code for it. > In this application, I'm looking at saving and loading an ascii text > file to/from the disk. To keep costs down and operation simple, we have > no display on the product, so the operator just hits a button to load a > file from the disk and another button to save it (with some precautions > to make sure current data in RAM or on disk is not accidentally wiped > out). I'm thinking of using PC format with a fixed filename, again > further simplifying it. There would be no way to format a disk, delete > the file, etc. Just load and store. > Has anyone done anything like this? Another approach I'm considering is > making a very small embedded 80x6 system that is a FD to EIA232 > interface. Then I could use something like DataLight's ROM-DOS and have > most of the code already written. I did something like this years and > years ago. There I did a 6802 system and wrote code to talk to a > Commodore 1541 disk drive. On the 6802 system you could save and load > applications programs, do a directory of the floppy, format floppies, > etc. Again, the goal there was to try to not have to write an operating > system, so I used Commodore's. > So... Floppies, anyone? > > Harold > > FCC Rules Online at http://www.hallikainen.com/FccRules/ > > ________________________________________________________________ > YOU'RE PAYING TOO MUCH FOR THE INTERNET! > Juno now offers FREE Internet Access! > Try it today - there's no risk! For your FREE software, visit: > dl.http://www.juno.com/get/tagj. > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

On Wed, 11 Oct 2000 07:31:52 -0400 Andrew Kunz <.....akunzKILLspam.....TDIPOWER.COM> writes: > I think Compact Flash is a much better solution these days. Higher > capacity, > smaller size, lower power, NO MOVING PARTS, PC-compatible. > > Did I forget anything? > > Media cost? Harold FCC Rules Online at http://www.hallikainen.com/FccRules/ ________________________________________________________________ YOU'RE PAYING TOO MUCH FOR THE INTERNET! Juno now offers FREE Internet Access! Try it today - there's no risk! For your FREE software, visit: dl.http://www.juno.com/get/tagj. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

On Wed, 11 Oct 2000, Harold Hallikainen wrote: > On Wed, 11 Oct 2000 07:31:52 -0400 Andrew Kunz <EraseMEakunzspam_OUTTakeThisOuTTDIPOWER.COM> > writes: > > I think Compact Flash is a much better solution these days. Higher > > capacity, > > smaller size, lower power, NO MOVING PARTS, PC-compatible. > > > > Did I forget anything? > > > > > > Media cost? And availability. But compact flash is really cool. I'm using it one design right now. Just for kicks, we got one of those IBM micro drives that plugs into a compact flash socket and our storage capability jumped up from 16Meg to 320Meg! Scott -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

I have done something like this for an embedded system. You create a floppy with a preallocated data file on it on some 'normal' system. If you start with a freshly formatted floppy and create one file on it DOS will always start that file in the first available cluster. Now you can go at the data area from the embedded side without any knowledge of the file structure. Bob Ammerman RAm Systems (contract development of high performance, high function, low-level software) -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

On Wed, 11 Oct 2000, gacrowell wrote: > http://www.iomega.com/hipzip/index.html > > > Be interesting to see if this takes off, article I read the other day said > there were three or four other vendors coming out with portable devices > using this disk. Ugh. Only 40MB storage.. kinda lousy for an MP3 player, but would be nice for embedded products as $10 a disk is much cheaper than what a 32Mb flash/sim/compact card would cost. Grab one of those IBM quarter-sized drives that can do 400MB and higher now I think. THAT is storage. :-) -- Ian -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

On Wed, 11 Oct 2000 06:56:06 -0700, you wrote: >On Wed, 11 Oct 2000 07:31:52 -0400 Andrew Kunz <akunzspam_OUTTDIPOWER.COM> >writes: >> I think Compact Flash is a much better solution these days. Higher >> capacity, >> smaller size, lower power, NO MOVING PARTS, PC-compatible. >> >> Did I forget anything? >> >> > >Media cost? This may be a very minor issue in some applications. The CF interface will certainly be simpler and cheaper, so your product will be cheaper (and smaller, lighter). If data transfer is an 'added extra feature' rather than essential to all users, CF may well be preferable to reduce the bottom-line cost of the product. If it's used for data transfer to a PC etc., most people will only need one disk/card. It also wouldn't surprise me at all if the cost of a CF interface and one small capacity card were comparable to, or less than, the cost of a floppy drive, controller, extra CPU resources, wiring, assembly time and power supply to support it. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

On Wed, 11 Oct 2000 21:45:34 +0100 Mike Harrison <@spam@mikeKILLspamWHITEWING.CO.UK> writes: > > It also wouldn't surprise me at all if the cost of a CF interface > and > one small capacity card were comparable to, or less than, the cost > of > a floppy drive, controller, extra CPU resources, wiring, assembly > time > and power supply to support it. > > I've already got the wiring for the chip on the board, so we have the price of the chip (maybe $5), the drive ($20). The power supply is already there. Wiring seems minor (ribbon cable plus power supply to drive). When the CPU is reading/writing disks, it doesn't need to do much else. There IS the requirement for coming up with the code and maybe the space to put it in (though the 18c452 seems to have a lot of ROM space)... So, I think I can add the drive for less than $50. Possibly less than the cost of one flash card. I appreciate the input... Thanks! Harold FCC Rules Online at http://www.hallikainen.com/FccRules/ ________________________________________________________________ YOU'RE PAYING TOO MUCH FOR THE INTERNET! Juno now offers FREE Internet Access! Try it today - there's no risk! For your FREE software, visit: dl.http://www.juno.com/get/tagj. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

>I think Compact Flash is a much better solution these days. Higher >capacity, >smaller size, lower power, NO MOVING PARTS, PC-compatible. > >Did I forget anything? > >Andy Price, number of pins required, FAT file system, practically single-sourced, murder to support on small micros (like PICs). The smallest PIC that can support a CF is 16C64 and the CF will use 23 pins on it (out of 33 IO). Some can be multiplexed (as inputs at least). The exact details of CF management for durability are secret afaik (strategy to prevent flash wearout while using FAT fs ?). The SONY memory stick looks much better from all of these points of view excepting price (which is in the same range). Peter -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! use KILLspamlistservKILLspammitvma.mit.edu?body=SET%20PICList%20DIGEST

Gary Crowell (gacrowell <RemoveMEgacrowellTakeThisOuTMICRON.COM>) wrote: >'e's not dead yet! >http://www.iomega.com/hipzip/index.html >Be interesting to see if this takes off, article I read the other day >said there were three or four other vendors coming out with portable >devices using this disk. Am I missing something here, or is it IOMega's ad writers? "1/5 the size [area?] of traditional music CD's" Also, 1/16th the capacity, and 10 times the cost! Looks like a good fit to replace compact flash, but for music?!? -- http://www.piclist.com hint: To leave the PICList spamBeGonepiclist-unsubscribe-requestspamBeGonemitvma.mit.edu

If it works, this would meet the requirements that somebody posted for a free hard drive. (James, the link please...) It might get you a free HD to release this. THere were some constraints put on the request, but I'd think this info would warrant a free drive of some sort for the poster. Andy "M. Adam Davis" <adavisEraseME.....UBASICS.COM> on 10/13/2000 10:28:16 AM Please respond to pic microcontroller discussion list <EraseMEPICLISTMITVMA.MIT.EDU> To: RemoveMEPICLISTEraseMEEraseMEMITVMA.MIT.EDU cc: (bcc: Andrew Kunz/TDI_NOTES) Subject: Re: [PIC]: Floppy storage I suppose you wouldn't be able to throw together a basic example of this code and schematic? A number of people have been looking for this in the past... -Adam "Mark A. Samuels" wrote: > > Using a 16F877, I've interfaced to a CF card using 22 pins, which reads from > and writes to FAT16 and FAT32 file systems, leaving 11 lines open for other > use. -- http://www.piclist.com hint: To leave the PICList RemoveMEpiclist-unsubscribe-requestspam_OUTKILLspammitvma.mit.edu -- http://www.piclist.com hint: To leave the PICList RemoveMEpiclist-unsubscribe-requestTakeThisOuTspammitvma.mit.edu

Well, I've already sold the HD, and the 'contest' expired back in June. There was a small amount of interest, but no one did anything more than send me links to mp3ar.com. (which is essentially a full implementation, just for CD-ROM drives. Only a little bit of modification would have been necessary to add HD writes (since the reads were there)) I'm still looking at other options to entice people to release valuable code... If this is released, I could probably come up with something usefull. -Adam Andrew Kunz wrote: {Quote hidden}> > If it works, this would meet the requirements that somebody posted for a free > hard drive. (James, the link please...) > > It might get you a free HD to release this. THere were some constraints put on > the request, but I'd think this info would warrant a free drive of some sort for > the poster. > > Andy > > "M. Adam Davis" <EraseMEadavisspamspamBeGoneUBASICS.COM> on 10/13/2000 10:28:16 AM > > Please respond to pic microcontroller discussion list <RemoveMEPICLISTKILLspamMITVMA.MIT.EDU> > > To: PICLISTSTOPspamspam_OUTMITVMA.MIT.EDU > > cc: (bcc: Andrew Kunz/TDI_NOTES) > > Subject: Re: [PIC]: Floppy storage > > I suppose you wouldn't be able to throw together a basic example of this code > and schematic? A number of people have been looking for this in the past... > > -Adam > > "Mark A. Samuels" wrote: > > > > Using a 16F877, I've interfaced to a CF card using 22 pins, which reads from > > and writes to FAT16 and FAT32 file systems, leaving 11 lines open for other > > use. > > -- > http://www.piclist.com hint: To leave the PICList > spamBeGonepiclist-unsubscribe-requestSTOPspamEraseMEmitvma.mit.edu > > -- > http://www.piclist.com hint: To leave the PICList > KILLspampiclist-unsubscribe-requestspamBeGonemitvma.mit.edu -- http://www.piclist.com hint: To leave the PICList EraseMEpiclist-unsubscribe-requestEraseMEmitvma.mit.edu

I am working right now on an article for Circuit Cellar, about this specific project. It's going to include a simple schematic for the interface, and code for read/write routines. I was able to get all the information about how to do this from the CompactFlash specification, which I saw someone posted a link to on the list within the last few days. As far as the FAT16 and FAT32 file systems, all my knowledge came from others' on the net. Again, within the last few days, someone posted a link to a FAT specification from Microsoft, which is the same document I used to get the majority of the information I needed to figure it out. -Mark {Original Message removed}

You know if you had 1500 beta testers you might get a better article <G> Andy "Mark A. Samuels" <spamBeGoneMSamuels99KILLspamWORLDNET.ATT.NET> on 10/13/2000 10:45:56 AM Please respond to pic microcontroller discussion list <.....PICLISTspam_OUTMITVMA.MIT.EDU> To: TakeThisOuTPICLIST.....TakeThisOuTMITVMA.MIT.EDU cc: (bcc: Andrew Kunz/TDI_NOTES) Subject: Re: [PIC]: Floppy storage I am working right now on an article for Circuit Cellar, about this specific project. It's going to include a simple schematic for the interface, and code for read/write routines. I was able to get all the information about how to do this from the CompactFlash specification, which I saw someone posted a link to on the list within the last few days. As far as the FAT16 and FAT32 file systems, all my knowledge came from others' on the net. Again, within the last few days, someone posted a link to a FAT specification from Microsoft, which is the same document I used to get the majority of the information I needed to figure it out. -Mark {Original Message removed}