Software and Errata for NESRGB Kit
Version 1.7 - I spent more time on RAM access
logic and it should be solid now.
Version 1.7 FBX Palette - Special
build with a different palette #1
Most boards sold between December
2016 and October 2017 have a fake voltage regulator IC fitted.
How to identify.
The genuine part has clear printing and a circular mould marking in
the centre of its package, the text depends on manufacture date.
The fake part has poor quality printing, no mould marking, the text
always reads HU1625 042.
The part number is MCP1703T-3302E/MB
manufactured by Microchip. The fake is probably a Chinese LM1117 or similar
The fake part is not a direct equivalent for the genuine one. The genuine
part is designed for stability with a ceramic output capacitors in the 2-10
uF range. The fake part is probably meant to have an electrolytic or
tantalum output capacitor in the 10-100 uF range. In some cases the fake
voltage regulator will oscillate. Here's
a video of this symptom.
Add an extra electrolytic capacitor between the 3.3V power rail and ground.
This should make the fake regulator operate correctly and prevent
oscillation. The easiest place to solder the capacitor is on the programming
header. The positive leg of the cap should be soldered to pin 1
(encircled) which is 3.3V, the negative leg soldered to pin 2 which is
ground. The capacitor should be either a 22 uF or 47 uF type - any voltage
rating will do.
The second, more difficult solution is to replace the fake voltage regulator
with a genuine part. To remove it from the PCB you can use a hot air rework
station or a soldering iron. The method for the soldering iron is to add
extra solder to each of the three pins, then hold the iron in such a way as
the tip is making contact with all three pins simultaneously. The thermal
connection between the centre pin and the tab will eventually cause the
solder to melt. Then the part will slide off the board.
How to update the PLD software
To update the software a JTAG programmer is required. I recommend an Altera
USB Blaster or clone.
There is an umarked 6 pin JTAG programming connection on the lower
left hand side of the board. Pin 1 is encircled.
- +3.3V power rail
The Altera USB Blaster requires the Quartus II Progammer Software for
Windows to be installed. The download is 185 MB and installation requires
700 MB of hard disk space. The USB Blaster drivers are included in the
package (find them in the folder after installation).
Quartus II Progammer Software for
Windows - Version 13.1 - working on Windows 7 and XP
Last updated 18/10/2017.
- Click Hardware Setup and select USB-Blaster
from the list.
- File -> Open -> NESRGB11.POF
- Check the boxes for Program/Configure and Verify
- Make sure the programmer is connected to the NESRGB board
- Click Start