On Thu, May 04, 2000 at 02:14:03PM -0700, James Newton wrote: > I wasn't clear enough... I need to be able to write to this thing from a PIC > in a remote device. Megabytes of data. Then pick it up, pull the card > (Compact Flash, SanDisk, PCMCIA FLASH, whatever), push it into the Laptop, > copy the file or files to hard drive, erase, reinsert into device and leave. > > Critical points: > A) ultra fast transfer speed. 16 Meg in several seconds. > B) standard unaltered laptop and no fancy software. > C) multi-meg storage ability. > D) fairly low power. will only fire up briefly, capture data, then shut down > so can't be ram or hard drive. > > Basically, if I could buy that part of a digital camera... You can. Just spent a few minutes reading up on CompactFlash for a future MIDI sequencer project. Basically CF is a flash memory with an embedded controller that makes it look very much like an IDE device. In fact it has what's called True-IDE mode that makes it look exactly like a minature IDE disk. You read/write the disk using the 8 byte IDE task file and the 16 bit dta bus. The bus can programmatically be reduced to an 8 bit bus if you need to conserve pins. Your project would have to maintain a DOS filesystem with a 12 bit FAT. This limits your filesystems to 32MB but I'm sure you can live with that. Dave Dunfield has a sample 12bit FAT implementation in C in this file: ftp://ftp.dunfield.com/embedpc.zip As for power consumption it seems to be quite small in standby but can grow up to 90ma a pop when writing. You can probably conserve simply by buffering 512 bytes of data in RAM then writing a whole sector when full. Interface to the PC is dead dumb simple. Plug in with a CF to PC-Card adapter, slide into the PC-Card port, treat as a hard disk. One caveat about True-IDE mode. It does require power-cycling the card to set this mode as it's detected on power-up. So you need a way to power-cycle the CF when you remove it. Take a look here for an Hitachi CF family that has all of the relavent specifications: http://semiconductor.hitachi.com/products/product_abstract.cfm?p_id=895 Also Digikey has the 50 pin connectors for CF. It looks like the winner to me. BAJ > > --- > James Newton mailto:jamesnewton@geocities.com 1-619-652-0593 > http://techref.massmind.org > All the engineering secrets worth knowing > > -----Original Message----- > From: pic microcontroller discussion list > [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Mark Willis > Sent: Thursday, May 04, 2000 13:53 > To: PICLIST@MITVMA.MIT.EDU > Subject: Re: [OT][EE] PCMCIA (PC CARD) data xfer to laptop > Importance: Low > > > I do this ALL the time - Lots of good answers for this one, James; Buy > a SanDisk (or Delkin, or Simple Tech., or or ) PCMCIA Flash card > (either Compact Flash with an adapter if needed, or a PCMCIA Type II > Flash Card) - install that into a unit like an SCM SwapBox (eBay has 'em > all the time - I have a spare, could ship it to you if you'll replace it > with a good unit.) $35 should get you one. > > http://search-desc.ebay.com/cgi-bin/texis/ebaydesc/results.html?query=scm+sw > apbox&dest=&cobrandpartner=x&SortProperty=MetaEndSort&SortOrder=&maxRecordsP > erPage=&srchdesc=y&category0=&category1=&category2=&category3=&textonly=n&tc > =&ht=1&st=&minPrice=&maxPrice=&ebaytag1=&ebaytag1code=&ebaycurr=&psURLSaveMe > thod=PersonalShopperSaveSearch&userid=&pass=&psreg=&psfreq=&psdura= > gives 10 hits > > I like these as the upper slot will handle a Type III HDD - can stack > that atop a Type II card and transfer data easily. > > Other co's make these as well, in differing varieties too (DataBook has > a Parallel Port unit that's not bad - get the later one if you go with > those, TMD-650 or newer.) > > Definitely check h/w and s/w requirements on the unit you plan to get > (the earlier ISA SCM's need an IRQ for the board, newer one's don't, > also these need one add'l IRQ for most installed cards.) > > Another answer: Get a NIC card (or parallel port NIC) for your laptop - > Pull the data down to the laptop's HDD, then transfer it onto the PCMCIA > Card if you still need to do that (may be able to do this directly if > you set it up right.) > > Also, SRAM cards are pretty nice (leave them plugged into some power > source i.e. powered-up desktop when not in use, or yank the battery, as > otherwise the battery eventually dies from the slow drain of the card; > Flash cards are LOTS less pricey, though, an SRam 4Mb card costs the > same as a 175Mb Flash card roughly. > > You'll usually need to initialize either card (CF / Flash or SRAM) - > sorta like "FDisk" for these media. > > BTW: "instantly"??!? > > Mark > > James Newton wrote: > > Does anyone know of a ready made embedded PCMCIA (PC CARD) writer that can > > write a format readable in the standard PC (laptop) like it was a drive? > > > > I have a friend who needs to instantly transfer mega-bytes of data to a > > standard laptop. > > > > --- > > James Newton mailto:jamesnewton@geocities.com 1-619-652-0593 > > http://techref.massmind.org > > All the engineering secrets worth knowing > > -- > I re-ship for small US & overseas businesses, world-wide. > (For private individuals at cost; ask.)