SC126 and garbage on serial port when booting RomWBW

Nige C

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Mar 11, 2022, 8:40:28 PM3/11/22

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Great kit and build. However I am now getting issues when booting RomWBW.

With SCM 126 Monitor Rom I get a great boot and solid serial connection.

With RomWBW I get load of garbage text.

Do I have a faulty flash rom. I have an XGecu TL866 II Plus rom programmer. I downloaded a current image SC126 WBW . Ending in .rom I need a .bin or .hex file?

Please help.

Wayne Warthen

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Mar 11, 2022, 10:08:21 PM3/11/22

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On Friday, March 11, 2022 at 5:40:28 PM UTC-8 nigec...@gmail.com wrote:

With SCM 126 Monitor Rom I get a great boot and solid serial connection.
With RomWBW I get load of garbage text.
Do I have a faulty flash rom. I have an XGecu TL866 II Plus rom programmer. I downloaded a current image SC126 WBW . Ending in .rom I need a .bin or .hex file?

That is odd. Can you confirm that you downloaded RomWBW-v3.0.1-Package.zip from the RomWBW gitHub Releases page? Then you burned SCZ180_126.rom to your EEPROM?

The .rom file is the correct file. Very unlikely that you have a bad ROM if the programmer verified the burn OK.

If the RTC is not working properly, then RomWBW may have failed back to a serial port baud rate of 38,400. Try setting your terminal to that baud rate.

Thanks,

Wayne

Nige C

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Mar 13, 2022, 7:54:37 PM3/13/22

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It’s something to to with the RTC. Steve Cousins said try installing a battery or removing RTC chip.

Installing battery worked for a while. But I had to remove RTC chip, and ROmWBW reliably boots now, and can be

Read at 115200 baud.

Wayne Warthen

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Mar 13, 2022, 8:54:50 PM3/13/22

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On Sunday, March 13, 2022 at 4:54:37 PM UTC-7 nigec...@gmail.com wrote:

It’s something to to with the RTC. Steve Cousins said try installing a battery or removing RTC chip.
Installing battery worked for a while. But I had to remove RTC chip, and ROmWBW reliably boots now, and can be
Read at 115200 baud.

OK, good. There seems to be a scenario where the RTC can be functional enough to pass the RomWBW existence test, but not functional enough to provide accurate timing. This messes up RomWBW which detects the wrong CPU clock speed.

Thanks,

Wayne

Nige C

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Mar 18, 2022, 11:06:37 PM3/18/22

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Sorted now. I had a flash card from RC2014 installed with RomWBW sio image, and PiZero card. Removed and reliable boots now.