Need some advice flashing 68HC11A8

[gecko242]

Hi All,

Having a real struggle writing the eeprom on a 68HC11A8. This is for a Blaupunkt RDR49, which has the security bit set, so when I read the dump it erased the eeprom.

I found a dump on this forum that supposedly will work, but having little luck flashing it. I have tried Motor11/411, Motorola Cracker 6, 6.2 and 7, all on windows XP and 98, with no joy. (All under virtualbox)

I have also tried PCBUG11, again no joy.

Latest step, I have the uP running on some stripboard, so bare minimum components. It appears to boot into special bootstrap mode OK, and accepts the talker, but no joy.

Starting to pull my hair out here... I would be mega greatful for some advice of any kind!
Cheers :)

[petku]

It is too long time ago, when I used MotorCracker for Motorola MCU. But if I good remember,
version 6 and upper was not working good for me. Only ver.4.3 . Look to attachment and try it.

If you trying read/write MCU on-board, disconnect RXD, TXD and RESET from rest of radio and
use Xtal 8MHz ??? (Don´t remember it). Best is use OLD PC with real COM, not virtualbox.

Or use another programmer like UPA, Orange etc.

[MrRepair]

This interface works for me. Must use PC with on board RS232 - no USB to serial. Put chip into bootload mode before read/write.

RS232programmer.rar (https://www.digital-kaos.co.uk/forums/attachment.php?attachmentid=681518&stc=1&d=1578899199)

[gecko242]

Thanks for the advice guys. Parts are on the way to build a MAX232 based programmer.

What version of windows does this software work under? XP? 98?

Thanks

[Zmann]

Not sure how you understand the security feature of HC11 family work. If the sec. bit of "NOSEC" has been reset (erased after wrong interfacing) there is nothing left to worry about. Then after on, if no connection, it's another matter !

[gecko242]

Okay, still no luck :( Built the MAX232 circuit as MrRepair suggested, and tested on old windows XP machine with hardware serial port. Circuit works well, joining tx to Rx echoes characters and the reset is flashing. But still no luck connecting with Motorola Cracker. Any other suggestions?