GAL chip programmer for Arduino
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GAL chip programmer for Arduino Board image

This is a GAL IC programmer software that allows to program GAL IC chips from various manfucaturers. It is based on work of several other people:

Bruce Abbott:

Manfred Winterhoff:

Yorck Thiele:

who did the most of the hard work of deciphering and publishing the programming protocol of these chips. Some of their early programs were Windows based and relied on presence of parallel port (LPT). Afterburner was written for Linux OS (also works on Win32/64, Mac OSX64), and requires serial connection to Arduio UNO, which does the programming of the GAL chip.

Supported GAL chips:

  • Atmel ATF16V8B, ATF16V8BQL, ATF16V8C, ATF16V8CZ, ATF22V10B, ATF22V10CQZ
  • Lattice GAL16V8A, GAL16V8B, GAL16V8D
  • Lattice GAL22V10B
  • National GAL16V8
  • Lattice GAL20V8B via adapter board

Update 25/03/2023: Added support securing the GAL contents. Use '-sec' parameter during write or verify to protect the GAL. Added support for Atmel's Power-Down feature on ATF16V8C and ATF22V10C GALs. The Power-Down is enabled or diabled depending on the JED file contents. Both features are based on GALmate software. Upload the latest afterburner.ino sketch and recompile the PC software, or use the precompiled PC software binaries (ver 0.4.2) in the 'releases' directory.

Update 21/03/2023: Added support for ATF16V8C. Based on GALmate code by Yorck. Upload the latest afterburner.ino sketch and use parameter '-t ATF16V8B' with the PC app.

Update 24/01/2023: fixed an isse where GAL chip could be accidentally zapped/damaged during insertion into ZIF socket. Please upload the latest afterburner.ino into your Arduino. The PC software may or may not need recompilation depending on its version. If you are unsure, either download the latest or recompile it.


  • Upload the afterburner.ino sketch to your Arduino UNO.

  • Connect the pins of the GAL chip to Arduino UNO according to the schematics images. Ideally use a PCB (ether etched or made in a fab) that's provided in 'pcb' and 'gerbers' directory. You can also hardwire on protoboard or breadboard.

  • Compile the afteburner.c to get afterburner executable. Run ./ to do that.

  • Set the programming voltage (VPP) on the voltage up-converter module (MT3608) depending on the GAL chip

    • Atmel ATF*: 10 .. 10.5V
    • Lattice GAL*: 12V
    • Others - between 10 - 14V - untested
  • Check the programming voltage (VPP) without the GAL chip being inserted / connected to Arduino UNO. Test the voltage on MT3608 module VOUT- and VOUT+ pins while running the following command:

    ./afterburner s
  • Check the chip identification by runnig the following command:

    ./afterburner i -t [GAL_type]

    If you get some meaningfull GAL chip identification like:

    PES info: Atmel ATF16V8B  VPP=10.0 Timing: prog=10 erase=25

    then all should be well and you can try to erase the chip and then programm it to contain your .jed file.

    If you get an unknown chip identification like:

    PES info: 3.3V Unknown GAL,  try VPP=10..14 in 1V steps

    then look at the troubleshooting section

  • Read the content fo your GAL chip. This only works if the contents of the chip is not protected. Use the following command:

    ./afterburner r -t [GAL_type]

    or to save the printed .jed fuse map to a file use:

    ./afterburner r -t [GAL_type] > my_gal.jed
  • Erase the GAL chip. Before writing / programming the chip it must be erased - even if it is a brand new chip that has not been used before. Use the following command:

    ./afterburner e -t [GAL type]
  • Program and verify the GAL chip via the following command:

    ./afterburner wv -t [GAL type] -f my_new_gal.jed

How aferburner works:

  • PC code reads and parses .jed files, then produces a binary which can be then uploaded to Arduino via serial port. By default /dev/ttyUSB0 is used, but that can be changed to any other device by passing the following option to afterburner:

    -d /my/serial/device
  • PC code of afterburner communicates with Arduino UNO's afterburner sketch by a trivial text based protocol. You can also connect directly to Arduino UNO via serial terminal of your choice and issue some basic commands manually.

  • Arduino UNO's afterburner sketch does 2 things:

    • parses commands and data sent from the PC afterburner code
    • toggles the GPIO pins and drives programming of the GAL content
  • more information about GAL chips and their programming can be found here:


If you decide to use a PCB rather than making breadboard or protoboard build, then you have several options.

  • Etch your own PCB.

    • The etching design is stored in 'pcb' directory, use afterburner_etch_1200dpi_bot.png file to transfer the design to the copper board.
    • It's a single sided design, but you'll have to patch 3 traces. See the the combined image where the patch traces are highlighted in blue color. Two short patch wires are located near the top left corner, the last one, slightly longer, is located underneath the MT3608 module.
    • Resistors are not through hole but smt 1206 package to reduce drilling.
    • The copper is on the bottom side, to make it easy to solder the socket and capacitors. However, that makes it a bit complicated to solder the Arduino pins. What needs to be done is to push the pins from the top part of the board (side without copper) so that the metal bits are flush with the plastic which keeps the pins together (plastic on the top), then solder the pins on the bottom side. You may then take off the plastic from the top side and slide it in from the bottom side.
    • You may need to flip the image before the transfer to the copper board, because the copper is on the bottom side.
  • Order it online on,, etc. Use one of the zip archive stored in the gerbers directory and upload it to the manufacturesr's site of your choice. Use for smaller PCB design that allows to program 16V8 devices only. Use for a bigger design that allows to program 16V8 and 22V10 devices. The price difference should be minimal as both designs fit within 100x100 mm area.

    • Dimensions of the fab_1_1 board is 55x53 mm
    • Dimensions of the fab_2_0 board is 57*72 mm
    • 2 layer board
    • PCB Thickness: 1.6, or 1.2
    • Copper Weight: 1
    • The rest of the options can stay default or choose whatever you fancy (colors, finish etc.)


  • it does not work!

    • double check the schematics and the connection between Arduino UNO and the GAL chip.

    • ensure the GAL chip is inserted to the IC socket the right way (check the pin 1 location)

    • ensure the VPP is set correctly on the MT3608 module. If unsure which voltage to use then try individual voltages one by one: 10V, 11V, 12V, 13V, 14V, 15V. Do not go beyond 15V as you may damage the GAL chip.

    • measure the VPP only when the GAL chip is physically DISCONNECTED (taken out of the afterburner socket). Some brands of the GAL chip (Atmel) - when connected - iternally lower the voltage on the Edit (VPP) pin (voltage divider?) and such voltage reading is misleading.

    • use an external power supply for your Arduino UNO, powering just via serial USB cable may not be sufficient for driving the GAL chip and the voltage up-converter

  • I've set the VPP voltage to 14 V, put the chip into the Ziff socket, turned on the power switch then run Afterburner with the 'i' command. My Arduino made a tiny short buzzing noise and then reset itself. What went wrong ?

    • most likely the VPP is set too high and the IC does not like that, it pulls the VPP pin down several times causing the Arduino to reset on brown out. Solution: reduce the VPP voltage by turning the pot clockwise on the MT3608 module.

    • this happens for example on ATF devices when VPP is set to 12V. ATF should use VPP set to 10V when programmed by Afterburner.

  • afterburner reports it can not connect to /dev/ttyUSB0, permission denied

    • ensure your user is member of the of the dialup group or alernatively run afterburner as superuser (use: sudo ./afterburner ...)

    • ensure no other programm on your PC uses that serial port. Close putty, minicom or other terminals you may be running.

  • afterburner fails to connect to /dev/ttyUSB0

    • ensure your PC is actually connected to Arduino UNO, check a serial device exists:
    ls -alF /dev/ttyUSB*
  • my MT3608 module does not have EN pin

    • that's unfortanetly a common problem. You have to mod the module as follows:

    • cut the PCB trace between pin 4 & 5 of the MT3608 chip. Verify the trace is cut by continuity probe (no beep is audible) between pins 4 & 5.

    |  Blue Potentiometer     |
    |   ______________
    |  |              |
    |  | SMT Capacit. |
    |  |______________|
    |   3  2  1
    |   |  |  |
    |  +-------+
    |  |       |
    |  |4  5   |
    |  +-------+
    |   |X |  |
    |<-- left long edge of the module
    • X marks the spot - here make the vertical cut. Do not cut the pins itself! Just cut the trace between the pins, which is only barely visible without magnification.

    • solder a thin keynar wire to pin 4 which is your ENable pin.

    See the MT3608 image in img directory for more details.

    • Once that is done, toggling the EN pin will change the output voltage of the module between 5V (actually slightly less than that) and the voltage set by the potentiometer (10V and more).
  • my MT3608 module does not seem to work - turning the pot does nothing

    • The pot needs to be turned at least 10 revolutions counter-clockwise to do anything useful. Keep trying.
  • where to get the MT3608 module ?

    • usual places: ebay, aliexpress
  • how to run afterburner on Win32, Win64 or MacOSX ?

    • the same way as on Linux: compile the source code
    • OR use pre-compiled afterburner binaries located in 'releases' directory
    • then run afterburner in terminal (use 'cmd' on WinXX) as described above
    • ensure your serial device name is passed via '-d' option. For example -d COM5 on WinXX
  • what are the .jed files and how to produce them

    • Use WinCUPL software from Atmel. Works under Wine as well.