If anyone could help, I would like to know if I could replace an AT89C2051 with AT89S2051 without any modification in hardware and software.
Let me explain, I have an project of ELEKTOR (IR light dimmer) based on the C2051 uC that cannot be programmed through the ICSP programmer that I already have, so I would like to replace it with S2051 uC if it is possible.
I have only one another question. Could I attach my USB ISP programmer (it support AT89S2051) direct to the MOSI, MISO, SCK, RST, VCC and GND port of the uC or I must add between some resistors, on my hardware, becouse I have never designed an uC with ISP programming capability.
My experience with this ISP stuff is, the reset pin must not connect to the other components while the ISP do its 'burning', so you may have a jumper when the circuit is in downloading process and when the circuit is running its program