The DAN][Controller is a simple and easy to build card that provides two SD cards as mass storage devices to ProDOS.
Optionally it can be extended with a network interface using a Wiznet W5500 adapter. The network interface provides an optional FTP server to remotely manage the Apple II volumes on the two SD cards. The network interface can also be used by the Apple II itself (using an updated IP65 network stack).
The card is based on the ATMEGA328P which is programmed with the Arduino development environment. It uses an 82C55 peripheral interface to connect to the Apple II bus. The design uses only five commonly available integrated circuits, the 74HCT08 AND gate, 74HCT32 OR gate, 82C55A peripheral interface, an eprom/eeprom memory chip, and a ATMEGA328P microcontroller, so should be reasonably future-proofed as much as any design for a 40 year old computer can be.
The card is also usable with the Apple III, using an driver for Apple III SOS.
You can directly download and send the Apple2Card-v1.1.1.zip to a PCB service like JLCPCB or PCBway, for example.
There is also an interactive BOM.
- The J1 connector is the ICSP connector for programming the ATMEGA328P.
- The J2 and J3 connector break out the bus pins of the Apple II.
- The J4 connect are the extra pins of the 82C55 broken out onto a connector.
- The J5 connector is for debugging.
- The J6 connector is for a Wiznet 5500 SPI ethernet controller (similar to Uthernet).
- JP1 is the ICSP power jumper. This needs to be closed for ICSP programming on the bench, to power the board when it is not plugged in an Apple II slot. Remove this jumper for ICSP programming when the board powered through an Apple II slot. This jumper doesn't matter for normal use.
- JP5 is a power jumper to separate the power-supply of the ATMEGA328P from the supply of the 82C55, EPROM, logic ICs and possibly Apple II mainboard. Can be left open when you connect an ICSP programmer to the card (so only the ATMEGA is powered while ICSP programming). Otherwise should be closed for normal use.
- JP2 is the bank switch jumper. It always needs to be closed. It can be hardwired/soldered closed.
- JP3, JP4, JP6, JP7, JP8, JP9, JP10 are the programming jumpers. If an EEPROM is used then these need to be closed during onboard programming (see EEPROM.SYSTEM below). However, these jumpers must remain open for normal use.
You may not need to solder the following components:
- Push button SW1 is only really useful for developers. You do not need to add it otherwise.
- Resistors R27 and R28 should only be soldered if you intend to connect an SD card extension cable to the J6 header. Do not solder these otherwise, or if you want to connect a WIZnet Ethernet adapter.
- Jumper JP1 only matters to allow the card to be powered through an external ICSP programmer. It can be hardwired/soldered closed (unless you intend to connect an ICSP programmer while the card is installed in an Apple II slot).
- Bank switch jumper JP2 always needs to be closed. It can be hardwired/soldered closed.
- Jumper JP5 always needs to be closed for normal operation. You would only open it if you intend to connect an ICSP programmer when the card is installed inside the Apple II. Otherwise it can be hardwired/soldered closed.
- Jumper JP6 only makes sense when you use an EEPROM (28Cxx) memory. Otherwise, if you use an EPROM (27Cxx) you can omit this jumper. It should be open for normal use.
- You can omit the pin headers for the J4 extender - and for J5, if you do not intend to use the card for development/debugging.
- Add a pin header to J1 to allow connecting an external ICSP programmer to the card.
- Add a pin header to J6 to allow the extension of a WIZnet SPI network interface.
The original version of the PCB used 10K pull-down resistors for R1/R2/R3/R7/R18/R21/R22/R23. The 10K resistors worked with most 82C55 devices, but were known to be too weak for some 82C55s. The listed resistors were replaced with 4k7 resistors in the current PCB version. The 4k7 resistors should work with all 82C55s (according to the data sheets).
For the memory device of the card an EPROM or EEPROM of 4K/8K/16K/32K can be used: a 27C32/27C64/27C128/27C256 EPROM or a 28C32/28C64/28C128/28C256 EEPROM. Only the first 512 bytes of that memory are used. Most of the code (including the boot/configuration program for the card) is stored in the Arduino flash memory - not in the EPROM - so the contents of this memory device are not expected to change often (while the ATMEGA chip's internal flash will be subject to more frequent updates).
The EPROM needs to be programmed with this eprom.bin file. It is a 512 byte file that can be burned to the memory chip using a programmer (such as a MiniPro / TL866 plus II). Again, only the first 512 bytes are used.
If a reprogrammable EEPROM (not EPROM) is used, there is also a program called EEPROM.SYSTEM which can program the EEPROM on the board. Jumpers JP2, JP3, JP4, JP6, JP7, JP8, JP9, and JP10 need to be closed when programming the EEPROM with the EEPROM.SYSTEM program.
However, for normal use, jumpers JP3-JP10 must be open - while only JP2 must be closed (JP2 can be hardwired/soldered closed).
The code for the ATMEGA328P is the Apple2Arduino sketch in the Apple2Arduino directory. It can be built and uploaded using the Arduino environment. However, preferably use the provided Apple2Arduino.ino.328p.with_bootloader.hex hex file, which includes the custom bootloader.
Once the binary with the custom bootloader is installed, the Apple II is able to do all further firmware updates of the ATMEGA (no more cables or ICSP programmers required).
The recommended fuse settings for the ATMEGA328P are identical to the default settings of an Arduino Uno board:
- lfuse: 0xFF
- hfuse: 0xDE
- efuse: 0xFD
The hfuse setting activates the use of the bootloader.
You can program the ATMEGA328P using a programmer (such as a TL866 plus II). The project contains the matching ".hex" and "fuses.cfg" file for programming:
cd Apple2Arduinominipro -p 'ATMEGA328P@DIP28' -c code -w Apple2Arduino.ino.328p.with_bootloader.hex -f ihex -eminipro -p 'ATMEGA328P@DIP28' -c config -w fuses.cfg
You can also use an ICSP programmer, connect the ICSP cable to the J1 connector of the DAN][Card and directly program the the ATMEGA328P on the board. Any 5V Ardunio board can be ued as an ICSP programmer: simply upload the "ArduinoISP" sketch from the Arduino IDE example section and make the appropriate wire connections to the J1 ICSP header on the DAN][ card.
If you use the ICSP connector of the DAN][Card then no SD cards should be present in the SD slots when the ATMEGA328P is flashed.
A command-line for programming the fuses and bootloader with "avrdude" is:
cd Apple2Arduinoavrdude -c avrisp -p m328p -P /dev/ttyUSB0 -U lfuse:w:0xFF:m -U hfuse:w:0xDE:m -U efuse:w:0xFD:m -Uflash:w:Apple2Arduino.ino.328p.with_bootloader.hex
You may need to adapt "avrisp" and the "/dev/ttyUSB0" port to match your programmer device. The "avrisp" matches the ArduinoISP (e.g. an Arduino Uno board programmed to be an ISP).
Once the custom bootloader was flashed to the ATMEGA, all further firmware updates can be done through the Apple II. The utility is even able to recover "bricked" cards - as long as the custom bootloader was installed. If the card was "bricked" (no longer responds as a drive), then you have to load the firmware update from a real disk (or a FloppyEmu).
Note: if you flashed your ATMEGA before the firmware update utility for the Apple II was introduced, then your ATMEGA does not yet contain the new custom bootloader. In this case the Apple II is unable to do the update. You will need to do one more manual update using an ICSP programmer (see above).
See the latest ZIP in releases with a disk containing the Arduino firmware update utility for the Apple II (use the DANIITOOL... disk). The ProDOS variant of the file (.po suffix) can also be stored as a volume on the DAN][ controller itself - so the firmware update can directly be loaded from the card.
- Load the "DANIITOOL..." disk (from a real disk, from FloppyEmu, or from a DAN][ volume).
- Enter the slot number of your DAN ][ Controller (Slot 1-7 for Apple II).
- The utility then asks to "PRESS CTRL-RESET TO START THE UPDATE". Yes, you need to press "CTRL-RESET", which triggers a warm-start, resets the DAN][ controller and immediately starts the firmware update.
There is a YT video showing the firmware update process of the controller.
The firmware update is now also possible with the Apple /// - and just as convenient as for the Apple II.
See the latest ZIP in releases.
Since Apple /// cannot use the ProDOS-based firmware disks (DANIITOOL...), a separate firmware update disk is provided. There is one disk image which can be copied to a real disk or to a FloppyEmu (FLOPPY_APPLE3_DAN2_FWUPDATE....po). This floppy version only works when booted on the Apple /// as drive 1 (.D1). There is an alternate volume image which can be stored on the SD card of the DAN][ controller itself (VOLxx_APPLE3_DAN2_FWUPDATE....po - the xx needs to be replaced with a volume number (0-F)).
This volume can be loaded directly from the DAN][ controller:
- Insert the floppy containing the "FLOPPY_APPLE3_DAN2_FWUPDATE....po" disk and start the machine.
- Enter the slot number of your DAN ][ Controller (Slot 1-4 for Apple ///).
- When the utility asks to "PRESS RESET TO START THE UPDATE", then press the single RESET button on the Apple ///. Do not press CTRL-RESET etc.
- The reset triggers a wam-start, resets the DAN][ controller and immediately starts the firmware update.
Either micro SD or micro SDHC cards may be used - with up to 32 GB capacity. Currently up to 128 ProDOS volumes per SD card are supported. To enable the use of the maximum number supported volumes, a 4GB SD card is required. In fact, FAT-formatted SD cards would need to be slgihtly larger than 4GB, due to the file system overhead. However, you will rarely need all of these volumes, so 4GB is absolutely fine.
Best performance is achieved with "Class 10" (or better) cards. "Class 4" (or lower) may result in slower disk access.
You can use SD cards with either FAT16 or FAT32 file system as the first partition. In FAT mode, the individual Apple II volumes on the SD card must be stored in the root directory of the card and be named "VOLxx.PO", with "xx" any hexadecimal number from 00 to 7F (up to 128 volumes). However, only the file extension (.PO) and the first 5 characters ("VOLxx") matter. The rest of the filename is ignored. So you can use filenames like "VOL21_TotalReplay.po" to keep your files organized. Example directory:
VOL00_TotalReplay.po
VOL01_InstantReplay.po
VOL02_Apple2Desktop.po
VOL03.po
VOL04.po
VOL0F_Foo.po
VOL22_Bar.po
VOL42_bla.po
VOL7F.po
Each volume file needs to contain normal Apple II ProDOS volumes (between 140K to 33MB).
Note: For backward-compatibility the old file naming scheme "BLKDEVxx.PO" is also still supported. However, this scheme does not support longer file names (no characters are ignored). Also, you cannot mix the naming schemes - not on a single SD card, nor on two SD cards plugged at the same time.
An empty ProDOS volume file of 33MB is provided within the ZIP file SingleBlankVol.zip.
Alternatively, raw block mode may be used (SD cards without any filesystem, just using raw data blocks to store the ProDOS volumes on the cards). Up to 4GB will be used for raw block mode.
To prepare SD cards for raw block mode, use the BlankVols.zip file. Unzip this file. The resulting "Blankvols.PO" file has a size of 512 MB (only covering the first 16 volumes). This needs to be written to a SD card using an utility such as Win32DiskImager or "dd" under linux. This file contains 16 concatenated and properly formatted (empty) ProDOS volumes.
You can simply concatenate this file multiple times to initialize more volumes (up to 128 volumes per SD card are supported). You can also use FTP to access and initialize the volumes individually (see below).
ProDOS disk images can be read/written by software such as CiderPress (a2ciderpress.com) so that you can use this to transfer files to and from the Apple II. Files can be copied onto the ProDOS disk image partition which can then be read/written by CiderPress and transferred to other media.
To make a volume bootable, copy the "PRODOS.SYSTEM" and other system files to be started on booting, for example "BASIC.SYSTEM".
The card can be installed in any Apple II slot, but slot 7 is a good choice: the Apple II starts at the highest slot number (slot 7) when searching for a bootable device. Usually a floppy controller is installed in slot 6. So the DAN][Card should be installed in slot 7 to make it the first boot device.
When the card is the primary boot device then the message "DAN II: PRESS RETURN" appears on the bottom of the screen when the Apple II is booting.
- If the RETURN key is pressed, then the boot menu is loaded to configure the card (see below).
- If the ESCAPE key is pressed, then the DAN][ Controller is skipped and the Apple II will search for the next boot device (e.g. your floppy drive).
- If any of the keys 0 to 9 are pressed, then the respective volume from SD card 1 is booted (quick access).
- If SPACE is pressed, then normal booting continues immediately. This will boot the volume which was most recently selected through the boot menu.
- If no key is pressed, then also normal booting of the most recently selected volume continues after a brief timeout.
If the RETURN key is pressed during boot up, the boot menu is loaded. The boot menu allows the selection of the volumes for the card's ProDOS drives 1 + 2.
- Use the ARROW KEYS (or SPACE/,) to select the active volume for each ProDOS drive and press RETURN to confirm.
- Alternatively press keys 0 to 9 or A to F to directly select volumes.
- Press LEFT/RIGHT ARROW to flip the volume pages (if you have more than 16 volumes per SD card).
- Press ESCAPE to abort and keep the previous drive configuration.
- Press I to enter the IP configuration dialog (if you have a Wiznet adapter, see below).
After selecting the volumes for drives 1 + 2 the system immediately boots from the volume selected for drive 1.
The card can be extended with an Ethernet interface. A cheap Wiznet 5500 device can be connected to J6 using a ribbon cable as indicated:
It's recommended to leave out the two resistors R27 and R28 on the controller PCB when you connect the WIZnet. These resistors connect signals to the J6 header which are not meant for the WIZnet device.
LED D11 (just above the J6 header) indicates network activity of the WIZnet adapter.
The CAD folder contains different STL designs for 3D printed brackets, which can be used to mount the WIZnet Ethernet adapter into the back of an Apple II or Apple ///.
When the Ethernet adapter is installed you can use FTP to remotely access the SD cards. The FTP access is very limited and only allows up- and downloading volumes to the volume files. The volumes are shown in two separate directories (SD1 and SD2) and list the volume files VOL00.PO-VOL7F.PO. Other files and other directories stored on FAT format disks are not accessible via FTP (any unrelated files and folders will stay on the SD cards, but neither be visible nor writable via FTP).
The Apple II access is suspended as soon as any FTP session is active. Disconnect your FTP client to resume Apple II access to the volumes.
FTP data is transfered at about 170-200KB/s. 140K disk-sized image transfers in less than a second. Full-sized 33MB images require about 2:45 minutes.
Notice that any RESET of the Apple II also resets the DAN][Controller and the network device. So avoid pressing Ctrl-RESET on the Apple II while up- or downloading volume images via FTP.
The FTP server cannot create new files, nor rename files. It also cannot enlarge files.
Prepare fresh SD cards before installing them by creating all required volume files (VOLxx.PO) in the root folder of the SD card: Just use an empty 33MB ProDOS template for each file. The FTP server is able to upload/download data to a volume as soon as the respective file exists.
Even if you prepare the SD card using ProDOS images of the maximum supported size (33MB), you will still be able to upload smaller ProDOS images via FTP (smaller is no problem, just larger files wouldn't work).
You can upload files of any supported size. Small standard 140K floppy disk ProDOS images also work (not just large harddrive volumes).
FTP access is also supported for SD cards using "Raw Block Mode" (see above). The SD card format is automatically detected. The volumes stored on raw block SD cards are also visible via FTP with standard filenames (VOL00.PO-VOL7F.PO) - just as if the SD card was using a FAT filesystem.
The normal preparation of SD cards for Raw Block Mode (writing the "Blankvols.PO" to the card, see above) is enough to make these cards also available for FTP access. The directory list of the FTP root directory also shows which format was detected for each SD card (RAW vs FAT).
The FTP server requires a fixed IP address. It is configured through the boot menu:
- As normal, press RETURN after booting to enter the boot menu.
- Then press 'I' instead of selecting a boot volume.
- Then enter the new IP address.
- To disable the FTP server, set the IP to "0.0.0.0".
The IP configuration is stored persistently.
The FTP server is active when a Wiznet module is connected and an IP adress is configured. The IP address is also shown in the boot menu.
The FTP server is limited to a single connection. If you use advanced FTP clients, like FileZilla, then you need to configure the FTP connection: see the "connection properties" and enable "Limit number of simulataneous connections" and set the limit to "1":
Note that ProDOS volume names and volume sizes are visible via FTP. The owner/group information is (ab)used to also report the ProDOS volume names. The displayed FTP file names are the normal FAT/DOS file names.
Alternatively to the FTP support, it is also possible for the Apple II to directly access the WIZnet Ethernet port. There is an extension for the IP65 network stack which adds support for the DAN][Controller interface to the WIZnet adapter. See the dsk folder for an example disk with IP65 examples (telnet client, ntp time synchronisation etc).
There is also a variant of ADTPro with the updated IP65 stack, supporting the DAN][ controller's Ethernet port - see here.
Notice that the FTP server on the DAN][ Controller is shutdown whenever the Apple II itself accesses the Ethernet port (using IP65).
The DAN ][ Controller can also be used with the Apple III, which does require some preparation:
The Apple III's I/O slots are compatible with the Apple II, so the DAN ][ Controller can be plugged into the Apple III normally.
Firmware updates of the DAN ][ Controller are also supported on the Apple III. The ZIP file in releases contains appropriate disks with the firmware update utility for the Apple III.
Apple III SOS always needs a driver to support a device (unlike Apple II ProDOS). There are two Apple III drivers which can be used with the DAN ][ Controller and work very well:
- The DAN2on3 driver, which was made specifically for the DAN ][ Controller. This driver is installed just like the original Profile driver - and needs to be added to your applications' boot disks.
- Alternatively, the soshdboot project provides a customized bootloader and SOS kernel which have integrated support for ProDOS interface cards. Volume images based on this project also support the DAN ][ Controller and can also be bootstrapped from the DAN ][ Controller.
To configure the DAN ][ Controller (select the active volume images) several methods are supported:
- There is an Apple III boot disk to configure the DAN ][ Controller. See the ZIP file provided by the DAN2on3 driver project containing the Apple III boot disk for configuration.
- Alternatively, you could install a custom Apple III ROM. This project provides a custom ROM which supports configuring the DAN ][ Controller and even bootstrapping "soshdboot" volume images, without using any floppy disk in the Apple III.
- Finally, you can also run the "Apple ][ Emulation" disk on the Apple III. And then call the DAN ][ Controller's builtin Apple II configuration menu, e.g. by calling "PR#1" (when the DAN ][ Controller was installed in slot #1).
Copyright (c) 2022 Daniel L. Marks
Copyright (c) 2023 Thorsten C. Brehm
This software is provided 'as-is', without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software.
Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions:
- The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
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