Hi,
Neil Kurzman said that , “I can assume you have an R/C reset on the 8052?”
Thanks Neil… I’m already using it.
It can’t solve this situation… Because proses ordinary is;
1-R/C Reset
2-8051 Start up ( It’s writing ports to logic-1)
3-My program…

Richard Erlacher said that :
“Low-side high-current drivers were driven with a positive output only to provide low-going drive to relays, LED cathodes, etc. Current was most commonly limited by resistors at the high-side, and the driver sank the current. As target devices became less power-hungry, the MCU's themselves became capable of driving some of them, hence, relatively high-current-sink low-current-source drivers at the MCU pins.”

Thans Richard. I know them.
8051 I/O maximum output current is 15-20mA (approximitly) .
Look at first schema in the below link
http://www.8052.com/forum/read/178883

I won’t calculate at length. But, I/O pin output current through to Base pin is approximitly 1,9mA.
However, 8051 can supprot 15-20mA. (approx. 10 times more)
Due to that reason, current don’t have to flow outside to I/O pin.

BTW, yes at first time low-active design was significat.
ULN2003 etc. chips are used. But, some problems are noticed.
Now, Hi-Active usage has started lately. UDN2981 etc..


David Prentice said that : “The solution is simple. An external pull-up or pull-down resistor… If you designed active-low, you use a pull-up. Active-high needs a pull-down.”
Thanks David…
I’ve already tried diffrent resistors between 5k and 10Ω. Anything hasn’t changed at the high value resistors. Output is not at the 10Ω.

Thanks, Kai Klaas…. Very much…

I think, I should use PIC series microcontroller for this kind of circuits….