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Topics - mockba

Hello everyone,

I have connected a 89C51RC2 via serial (using a PL2303 USB-Serial adapter) going thru a MAX232 to my laptop.
The MCU is running on a 12Mhz Xtal and seems to be working fine. I have connected it with EA up, PSEN down and tried with ALE both up and disconnected. The "circuit" is just the chip on a protoboard with the XTAL and reset circuit (RC) in place.
I have configured the serial port to 9600 8N1 and opened Putty ... then I type "U" and get "U" back, meaning the MCU bootloader discovered the speed and replied.
Then I open the FlashMagic's terminal and do the same thing ... reset the circuit and type "U", getting a "U" back.
In fact from that moment on I get back anything I type, echoed back by the MCU.
However, when I command FlashMagic to start writing (or anything else) I see both TX and RX blink once (checked on the oscilloscope to make sure the MCU was sending something back) then I get a message stating that it was unabe to communicate and suggesting me to either lower or increase the speed.
I have read the post regarding speed autodiscover and tried almost everything there. I just didn't try replacing the USB adapter as I am getting a response back both thru putty and flashmagic's terminal.
At this point I don't know what else I could do.
I have tried programming the device on a Willem compatible (GQ-4X) programmer but it doesn't seem to be supported.

Any insight on this would be much appreciated.

Thanks everyone for even reading up to this point.

Best regards,
Marcelo "Mockba" Dantas.