My Problem is that uVision always shows monitor 51 not connected. I'm using keil c51 7.50 and uvision 3.05c. I want to use RS-232 interface communication with ATMEL "AT89S53" 1. In the "option for target" window of Keil. I have following setting: ------------------------------------------------------------- Target Atmel AT89S53. Memory Model: compact: variables in PDATA; Code Rom Size: Compact: 2K functions, 64k programs. Operation system:RTX-51 full. ---------------------------------------------------------------- Debug Use: Keil Monitor-51 Driver Port:COM 1 RTS:Active Baudrate: 19200 DTR: Active. Choose cache options for DATA, XDATA, IDATA, CODE. choose serial interrupt. Choose Load Application at Startup. Choose Breakpoints, Watchpoints, Memory Display, Toolbox. -------------------------------------------- However, in the Monitor-51 Identification, it always says" Monitor-51 not connected" 2. The 8051 board i use is "MINI-MAX/51-C MICROCONTROL BOARD," made by BiPOM Electronics. The 8051 chip is "ATMEL 89S53." The spec is: 1.12K In-System Programmable Flash Memory. 2.256 bytes of RAM. 3.Nine bytes of RAM. 4.Three 16 bit Timer/ Counters 5.Programmable UART Serial Channel. 6.SPI Serial Interface. 7.Programmable Watchdog Timer. 8.32 general purpose I/O pins 3. I have tried Micro-IDE software made by BiPOM, it can communicate with this board through RS-232 very well. Therefore, it seems the communiocation problem occurs in the Keil Software itself. I really don't know what is going wrong, and this is my first time using 8051 system. Could anybody help me? RAY
Oh, sorry. I missed a point of your message. If you can communicate to your board via the Micro-IDE, then that's how you would load MON51 to your target board. You may still need to configure a MON51 version just for your board. Once again, go to the PDF file to see how to configure for your board.