Firmware patch for Kenwood TS-950SDX HiFi AM mode available
Posted: Thu Jun 16, 2011 3:13 pm
Well, I've thought about it, I've talked about it, and now I've gone and done it. With help from da VooDoo crew, some elbow grease and a bunch of trial and error, I've managed to patch the firmware for the Kenwood TS-950SDX to correct the famous "AM doesn't work in HiFi mode" problem. I finally got the code modified just right and tested it just last night -- it ended up working perfectly. The radio's behavior is completely unchanged, except now it transmits in AM when the LPF is set to "off" without needing any manual jiggery pokery or the off-board computer assist program that I wrote.
I now have the only TS-950SDX in the world where the statement that "voodoo audio won't work on AM" is 100% untrue.
So without further ado, here it is. If you have access to an EPROM programmer and want to try the patched firmware yourself, you can download it from here:
http://people.freebsd.org/~wpaul/ts-950 ... patch.html
The main CPU in the TS-950SDX is an NEC uPD7810. It's a relative of the Zilog Z80. I managed to disassemble the firmware and modified it to work around the glitch in the DSP unit's gate array which prevents AM from working in HiFi mode. The ZIP file provided on the page mentioned above contains technical details about how the modification works. The patch is based on the most recent firmware available for the TS-950SDX, version JQGA, so you get the benefit of all Kenwood-supplied firmware bug fixes too. Both the original unmodified firmware image and the patched image are included.
If you don't want to change your radio at all, you can still use the off-board CAT program, which is still available here:
http://people.freebsd.org/~wpaul/ts-950 ... m_cat.html
So now there's not one, but two ways to do HiFi AM with your TS-950SDX. How's that for a bargain! For simplicity, both pages can be accessed from here -- just name your poison:
http://people.freebsd.org/~wpaul/ts-950sdx/am_dsp
I want to thank the VooDoo Guru for his help, because without his assistance this wouldn't have been possible. (Or at the very least, it would have taken much longer.)
As with the CAT program that I wrote, the author disclaims any liability for damages resulting from use of this code. If it breaks, you get to keep both pieces.
If anyone has any questions or comments, please let me know. I'm not expecting to have to update the firmware again, but if so I'll keep ya posted.
Share and enjoy!
-Bill
I now have the only TS-950SDX in the world where the statement that "voodoo audio won't work on AM" is 100% untrue.
So without further ado, here it is. If you have access to an EPROM programmer and want to try the patched firmware yourself, you can download it from here:
http://people.freebsd.org/~wpaul/ts-950 ... patch.html
The main CPU in the TS-950SDX is an NEC uPD7810. It's a relative of the Zilog Z80. I managed to disassemble the firmware and modified it to work around the glitch in the DSP unit's gate array which prevents AM from working in HiFi mode. The ZIP file provided on the page mentioned above contains technical details about how the modification works. The patch is based on the most recent firmware available for the TS-950SDX, version JQGA, so you get the benefit of all Kenwood-supplied firmware bug fixes too. Both the original unmodified firmware image and the patched image are included.
If you don't want to change your radio at all, you can still use the off-board CAT program, which is still available here:
http://people.freebsd.org/~wpaul/ts-950 ... m_cat.html
So now there's not one, but two ways to do HiFi AM with your TS-950SDX. How's that for a bargain! For simplicity, both pages can be accessed from here -- just name your poison:
http://people.freebsd.org/~wpaul/ts-950sdx/am_dsp
I want to thank the VooDoo Guru for his help, because without his assistance this wouldn't have been possible. (Or at the very least, it would have taken much longer.)
As with the CAT program that I wrote, the author disclaims any liability for damages resulting from use of this code. If it breaks, you get to keep both pieces.
If anyone has any questions or comments, please let me know. I'm not expecting to have to update the firmware again, but if so I'll keep ya posted.
Share and enjoy!
-Bill