693d05b755
* Add gitattributes to handle line endings. * Import the unmodified LTEMM source. From https://www.lo-tech.co.uk/wiki/LTEMM.EXE. * Add DOSBox and TASM for build. * Add build script for LTEMM. * Modity LTEMM driver for XTMax. * Import the unmodified SDPP source. From https://forum.vcfed.org/index.php?threads/sd-card-to-parallel-port-driver-for-msdos-ver-1-1.42008/. * Add Borland C++ 3.1 (Minimal) for build. * Add build script for SDPP. * Modify SDPP driver for XTMax. * Commit pre-built binaries for LTEMM and SDPP. * Reorganize the drivers into a new folder.
73 lines
3.6 KiB
Plaintext
73 lines
3.6 KiB
Plaintext
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SD card driver for parallel port
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I wrote this to simplify data transfer between my IBM PC and my laptop, because my laptop does
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not have a 360k floppy drive but does have an SD card slot.
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WARNING: I take **no responsibility** for any damage to your computer, parallel port, or SD
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card, or any data. You use this driver at your own risk. It is highly recommended you use
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an expendable parallel port card with your expendable SD card, and your expendable data.
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It is recommended that you use a level converter IC with between your 5 volt parallel port
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outputs and the SD card 3.3 volt inputs. This project is intended as a fun hack for hobbyists
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and enthusiasts and not for serious work.
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This driver is made available under the GNU General Public License version 2. It incorporates
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modified code from ELM Chan Fat FS (http://elm-chan.org/fsw/ff/00index_e.html).
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Usage:
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In your config.sys file
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DEVICE=SD.SYS /d /k /p=<partition #> /b=<port base index>
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Loads and installs the SD card driver.
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/d = debugging mode (displays copious debugging messsages)
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/k = use card detect signal to inform dos that card is attached
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/p = partition number (1-4) to partition in MBR to use. Default: first available.
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/b = port base index of parallel port, one of
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1=0x3BC, 2=0x378, 3=0x278, 4=0x3E8, 5=0x2E8
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Default: 0x378
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For best results, format your SD card with a FAT16 partition which is less than 32 MB in size.
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NOTE: Many versions of DOS don't know how to handle FAT32, and many can't have FAT16 with a
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partition size greater than 32 MB. Therefore, if you want to play with this, make your parition on
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the card FAT16 and less than 32 MB. This assures the best compatibility. You can have multiple copies of the
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driver loaded if there are multiple partitions on your SD card you want to use simultaneously.
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I have used Adafruit's microSD adapter
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(http://www.adafruit.com/products/254?gclid=CLH7l4iEkrwCFQPNOgod7BkAQA)
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if you want a relatively simple way to interface your PC parallel port to
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the SD card. The adapter provides the 3.3 volts needed to power the SD card, as well
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as a the level shifting between the 5 volt parallel port output and the 3.3 volt input.
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If you directly connect a 5 volt output to a 3.3 volt input, you risk latching up the
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3.3 volt input and damaging the card or computer from exceesive current.
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Some have used series resistors instead of the level converters, but I found this
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to not be that reliable and still may have this problem. Also, some SD cards MISO/DO
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outputs are unable to drive a TTL input of some parallel ports, so you may need to add
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a buffer between the two as well. I have found quite a bit of variability in the drive
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current required for the inputs of various parallel ports.
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The driver uses the very slow serial peripheral interface (SPI) mode of the SD card. The
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speed, which depends on your PC speed, could be as slow as 10 kilobytes/second. This is
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not a replacement for your hard drive. Your parallel port should be configured for standard
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mode (not bidirectional) if applicable.
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The connections between the parallel port and the SD card are as follows:
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Parallel port SD card
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PIN 25 signal GND GND (Vss)
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+3.3V Vdd (power)
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PIN 2 signal D0 CMD / MOSI / DI (SPI data in)
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PIN 3 signal D1 SCLK / CLK (SPI clock)
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PIN 4 signal D2 DAT3 / CS (SPI chip select)
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PIN 13 signal SELECT DAT0 / MISO / DO (SPI data out)
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PIN 11 signal BUSY Card detect (if you SD card slot has one)
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For similar setups, look up parallel port to JTAG adapters which are used for in circuit
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programming and debugging.
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Good luck and be careful!
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