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Flash Magic generate PSEN and RST Signal not stable for reset every time.

My hardware . P89C61X2

PC win98 :

I use the oscilloscope to find wave edge width not stable

Normal reset
http://www.usync.tzo.com/right_reset.jpg

Error reset
http://www.usync.tzo.com/error_reset.jpg


I use the same hardware , but some time could reset 89c61x2 , and some time wrong.

Could you give me some advice

Thank you.

Best Regards,
Patrick Chiu

I use "Flash Magic Application Note 1", Figure 1 to build my ISP Tool

and have some problem.

In "Flash Magic Application Note 1", tell me that when the com port is closed , RTS and DTR are at a RS232 voltage level below -3V.

But when I put every thing together and power on .

PSEN always Low, and RST alway high.

I found DTR, RTS on 0.7V

this is my circuit diagram

http://www.usync.tzo.com/fm_isp.pdf

PSEN pull up 10k , and  RST 10uF, 10k at other page.

This problem is confuse me serval day .

Have anyone can tell me how to do ? :-(

Thank you very much .

Patrick Chiu.