I´ve tried to program a 16F628 externaly connected to 8048 via the ISCP port. But the program says that it can´t find any chip. How is it ment to be?
Maybe a connection problem or µC on your board is controlled by other parts on your board.
It could not be an ICSP problem only, because the connection on the ICSP connector are 100% the same as the one of the IC sockets on the PCB.
Please check if programming on the board is OK.
It’s no problem to program pic’s when placed in holders on the board. It’s just when i try to use ISCP-port it fails.
Maybe cable is to long? or is not shielded, use shielded cable and max 30cm.
Could also be in impedance problem. Use CLK and PGM only for ICSP purposes.