Writing a new BootRom/BIOS using the CH341A programmer

I purchased a CH341A programmer to replace a BIOS chip in my existing logic board. This CH341A programmer has the capability to write to 24xx and 25xx chips.

NOTE: I thought I was supposed to modify input voltage to avoid destroying the programmer, after reading all the reviews on Youtube. It was time wasting mistake to mod the CH341A to take 3.3V inputs before doing a test run. In the end, I had to undo all the mods; namely

  1. cutting the 5V VCC and connecting the VCC to 3.3V from the linear regulator.
  2. connecting pin 9 on the CH341A chip to 3.3V.

Chiefly 3.3V was insufficient to power the pomona clips. Reinstating the 5V input to the CH341A made the pomona clips work.

You don’t need to mod the CH341A programmer! It works as advertised without mods.

Here are pics for positioning the pomona clip and adapter to the CH341A programmer.

Note the position of the red line. This red line represents power and must be aligned to the corner pin nearest to the O marker (denoting Pin 1) on the ROM chip.
Note the red line and where the adapter (green) indicates position 1. Position 1 should be pointing to the jackpot handle.

I am running on macOS with homebrew so I elected for flashrom (only choice actually) so…

brew update && brew upgrade
brew install flashrom

next navigate to the location of the BIOS firmware and run
flashrom —-programmer ch341a_spi

It will tell you whether was the CH341A programmer detected. If it says no detection, then you will need to try a new USB port (direct from the laptop/desktop and not through a unpowered USB hub) or swap a new CH341A programmer.

Now attach the ROM chip to the ponoma clips and run the same again.
flashrom --programmer ch341a

This time it will try to identify the ROM chip and ask you for the specific model of the ROM chip.
Now lets write the firmware onto the ROM chip.

flashrom --programmer ch341a_spi -c MX25L3206E/MX25L3208E -w <firmware.bin> -V

-c refers to the ROM chip model that I used
-w refers to the file to write to the ROM chip
-V refers to verbose mode, instruct flashrom to tell you what’s happening.

The above command will include the verification process, countercheck for any errors. (None came up in my case)

Another way to countercheck is to read from the ROM chip after writing to it. The command is similar as follows:

flashrom --programmer ch341a_spi -c MX25L3206E/MX25L3208E -r <extracted_firmware>

Hope this helps. If anyone needs a video, i’ll make one and post on Youtube.

Louis Ng vs Amy Khor: MPs debate proposed ban on smoking near windows of HDB flats

I read with interest on the exchange between Louis Ng and Amy Khor on the proposed ban on smoking near the windows of HDB flats. I had firsthand experience on 2nd hand smoke waffling into my bedroom and kitchen courtesy of chimneys one floor lower. The smell was especially acrid when the smoker was puffing cheap cigarettes, and further in the 33 degree Celsius weather.


In response to Ng, Khor said that her ministry was equally concerned about secondhand smoke and is just as keen to resolve the issue – just not through the means Ng proposed.

“Unfortunately, besides the fact that such legislation could be highly intrusive. There are significant practical challenges in enforcement that limit effectiveness,” said Khor.

First, it would be difficult to gather evidence of a smoking offence as the culprit will need to be captured smoking or holding a lit cigarette, in order for enforcement to take place.

“(A) smoker can easily hide behind the pillar frosted glass windows or curtains to avoid detection by the camera. Overall, this may entail the deployment of significant resources, without achieving effective outcomes,” she added.

Second, it would be difficult to find a vantage point from which to place cameras to capture smokers in the act without being excessively intrusive. Khor noted that this is unlike the case for cameras set up to catch high-rise litterbugs as these are placed at ground level some distance away from HDB blocks and only capture a building’s facade.

“Finally, this will exacerbate existing concerns about privacy and infringe upon the (home) owners’ rights to his or her own private space,” said Khor.

What had you been smoking Amy? I can’t care less about the home owner prancing butt naked in their own private space. What about my private space to get fresh, uncontaminated air?

“We must work hard to address the issue of secondhand smoke from homes, but legislation against smoking at windows or balconies may not be that silver bullet,” she added.

Khor said that out of 11,400 smoking complaints received in the first four months of this year, 58 per cent (6,630) were from people living in residential estates.

While there has been a rise in the number of residential smoking-related complaints due to more people working from home during the COVID-19 pandemic, Khor said that only 320 cases involved smoking in homes.

Khor said that the government will instead pursue a three-pronged approach in tackling the issue. This would involve working to engender greater social responsibility and instil in residents a consideration for the health and well-being of others, including their neighbours.

She said her ministry will work with other agencies – such as the Health Promotion Board and Ministry of National Development – to explore effective ways of achieving this goal through, for instance, targeted messages on key platforms, including social media channels.

“Second, we will examine more ways to facilitate productive conversations between neighbours to deal with difficult situations, before they escalate into intractable disputes,” said Khor.

Thirdly, her ministry will study how such disputes over secondhand smoke can be better addressed by the interagency community dispute management framework although she noted that she hoped most cases would not have to end up in community mediation.

“The best way to protect against secondhand smoke is for family members and neighbours to help smokers cut down and quit smoking. And if they have to smoke, not to light up at home, and instead smoke at non-prohibited areas,” said Khor.

Replying to Khor’s explanation, Ng said “the problem is that we are viewing this as a neighbourly dispute issue.

“And I think if we view this as a public health crisis and the policy direction, then the policy outcome might be completely different,” he added.

Does the above highlighted in bold sound like a challenge? Sounds like one to me. 🙂