In message <2C6AE5442E4@fs7.plessey.co.za>, Werner Terreblanche writes >Atmel seems to continiously impress me with all the innovative >products they bring us all the time. Anybody here looked the spec >sheets of Atmel AT89S8252 lately? This fella is 89C52 >compatible, but with the difference that it is completely in-circuit >programmable by downloading the 8Kb of code onto the microprocessor by >means of an onboard SPI interface for serial program downloading. On >top of this it also boasts with 2Kb of onboard EEPROM! > >The AT89S8252 provides the following standard features: 8K bytes of >Downloadable Flash, 2K bytes of EEPROM, 256 bytes of RAM, 32 I/O >lines, programmable watch-dog timer, two Data Pointers, three 16-bit >timer/counters, a six-vector two-level inter-rupt architecture, a full >duplex serial port, on-chip oscillator, and clock circuitry. > >This means that you do not need a fancy programmer to program this >device and you can even let your customer do code updates in the >field on a working product. All you probably need is a very simple >interface between your PC and the SPI port. I tried to search for >any implementations of such a simple interface last night, but found >nothing. Atmel also did not have any application notes regarding >this on their web site, as far as I could tell. I'm sure it will not >be difficult to implement, but I do not want to waste an extra day if >this info is already available somewhere on the net. If someone else >has also already looked into this and know of an easy implementation, >then I would very much like to hear from you. The Atmel AVR 1200 controller has the same type of I/F. They can be programmed in-circuit from the printer port with a capacitor between two of the pins - virtually zero hardware. 1200 programming software and hardware details are here: http://www.sistudio.com/avr.html Leon -- Leon Heller: leon@lfheller.demon.co.uk http://www.lfheller.demon.co.uk Amateur Radio Callsign G1HSM Tel: +44 (0) 118 947 1424 See http://www.lfheller.demon.co.uk/rcm.htm for details of a low-cost reconfigurable computing module using the XC6216 FPGA