Arduino 2009 Board
Currently the firmware is implemented on an Arduino 2009 board with an ATmega168 running at 16 MHz. Similar AVR board should work, too, but note that an FT232 USB-to-serial bridge with RTS/CTS hand shaking pins available at the AVR is required.
The additional hardware required for the Arduino board consists of an adapter for the Amiga parallel port, the RTS/CTS handshake lines on the board itself, and 3 LEDs to show the operation modes.
All parts are fairly simple to construct.
1.1 Amiga Parallel Port Cable
You need to build a cable from the Amiga Parallel Port (DB 25 male) to the Arduino. Try to use only a short wire length otherwise signal quality will suffer.
Up to 10 cm are suitable lengths.
. Amiga Parallel Port        Function         Arduino .   17 ... 22               GND              GND Pin .   1                       /STROBE          DIGITAL 2 (PD2) .   13                      SELECT           DIGITAL 3 (PD3) .   11                      BUSY             DIGITAL 4 (PD4) .   12                      POUT             DIGITAL 5 (PD5) .   8                       DATA 6           DIGITAL 6 (PD6) .   9                       DATA 7           DIGITAL 7 (PD7) .   10                      /ACK             DIGITAL 8 (PB0) .   2 ... 7                 DATA 0 ... 5     ANALOG 0 ... 5 (PC0 ... PC5)
1.2 RTS/CTS RS 232 Handshaking
You need to connect the RTS/CTS lines from the FT232 to your AVR. On the Arduino 2009 the RTS/CTS lines are available on solder pads on the board. Just solder a wire and connect them to the given AVR pin:
Arduino RTS/CTS Line Connections
- CTS (OUT):Â Â Â Â DIGITAL 9 (PB1)
- RTS (IN):Â Â Â Â Â DIGITAL 10 (PB2)
1.2.1 CTS Solder Pad
. Solder Pad X3                             DIGITAL . . 4  3  2  1                                     . . (x) (x) (x) (x)                                   . .              |                CTS                * 10 .              +----------------------------------> * 9 .                                                    * 8 .                                                    .
The vanilla Arduino board does not allow to control the HW CTS serial signal from the AVR chip. But this is required to allow high performance data transfer for the dtv2ser firmware. Fortunately,this signal of the FT232 chip is available on the solder pad X3 and can be added by soldering a wire from there to a pin that is connected to the AVR port labeled “DIGITAL 9”.
1.2.2 RTS Solder Pad:
. Solder Pad X3                             DIGITAL . . 4  3  2  1                                     . . (x) (x) (x) (x)               RTS                . .                         +---------------------->  * 10 .                         |                         * 9 .                         * *                      . .                      unpopulated solder pads      .
The RTS line is available on the left solder pad of the unpopulated resistor found on the right hand side of the X3 pads. The RTS line needs to be connected to port DIGITAL 10 on the AVR.
NOTE: Do NOT connect the line to the right pad and do NOT short circuit poth pads. The right line is the RESET line and will restart your board every time RTS is triggered…You have been warned 😉
1.3 Adding LEDs
Three LEDs with colors red, orange/yellow and green are soldered with 220 Ohm resistors to +5V and the following DIGITAL pins:
.                     Red LED . Reset *        +------>|----| 220 |--------------* DIGITAL 13 .   3V3 *        | Orange LED .    5V *---------+------>|----| 220 |--------------* DIGITAL 12 .   GND *        | Green LED .   GND *--+     +------>|----| 220 |--------------* DIGITAL 11 .   Vin * | .          | .          v This line is used for the Amiga parallel port
That’s it! Your plip2slip HW is ready!
