The logic on the CoCoVGA main board is mostly contained within the larger surface-mounted FPGA. FPGA stands for Field Programmable Gate Array. This means that in the field (such as in your home or office), you may upgrade the configuration of the hardware logic gates within the FPGA chip using a hardware release provided via this web site. This programming/configuration is performed serially by way of a protocol defined by and therefore known as JTAG (Joint Test Action Group).
From time-to-time, new CoCoVGA FPGA hardware releases may be made to fix bugs or provide feature enhancements. These can be used either temporarily (by programming the CoCoVGA FPGA directly) or permanently, by updating the flash memory on the CoCoVGA main board.
You will need:
- an Altera Byte Blaster USB cable
- Quartus Prime Pro Edition Programmer and Tools software for your PC (more details in step 2, below)
- an FPGA image from the Downloads page, either:
- .sof file for temporary updates - OR -
- .jic file for permanent updates
Pictured below is one example of an Altera Byte Blaster USB cable:
- If you have not already installed your CoCoVGA main board in your computer, please do so. See Installation for more information.
- If you do not already have it installed, download and install the Quartus Prime Pro Edition Programmer and Tools provided on Intel/Altera's web site. It may be necessary to sign up for a free account. From the link, select the Additional Software tab, then under Stand-Alone Software, check only Quartus Prime Pro Edition Programmer and Tools and click Download Selected Files:
- Turn off your computer which has CoCoVGA installed in it and disconnect disk drives, IDE/SDC/MMC/flash and other data storage peripherals.
- Plug in your Altera Byte Blaster USB cable, first to an available USB port on your computer, and then to the small JTAG header connector on your CoCoVGA main board (labeled "JTAG").
- Turn on the computer which has CoCoVGA installed in it.
- Start up the Quartus Prime Programmer Pro Edition.
- Click "Hardware Setup..." and select the USB-Blaster plugged into one of your USB ports. Close this pop-up.
- Click "Add File..." and select the .sof or .jic file you would like to program. Ensure that Program/Configure is checked. Verify and Blank-Check are optional.
- Click Start to begin programming.
- See below for next steps - generally, a temporary .sof causes automatic FPGA reconfiguration whereas a .jic is permanent and requires power cycling your system upon completion of the programming step.
If programming a temporary .sof, the "Progress:" bar should reach "100% (Successful)" and then CoCoVGA should reconfigure itself and you should see the appropriate version number in the banner. This configuration will stay present and active within the FPGA until you either reboot your CoCo or Dragon or press the "RECONFIG" button on the CoCoVGA main board.
If programming a permanent .jic, wait until the "Progress:" bar has reached "100% (Successful)" and then power-cycle your CoCo or Dragon. Once your VGA monitor syncs, you should see the appropriate version number in the banner.