Tue Nov 30 15:10:04 PST 1999

The Circuit Cellar Online article titled "A $25 Web Server" and its
associated ZIP archive have a number of known errors.

 1. Figure 1, the breadboard schematic, shows the WP signal on the 24LC128
    serial EEPROM chip (U2, pin 7) connected to +5V.  That pin should
    either be unconnected, or connected to logic ground.

 2. Figure 1, the breadboard schematic, shows a 4 MHz ceramic resonator
    (Y1).  The correct value is 8 MHz.  When using the sample breadboard
    firmware supplied with the ZIP archive the serial port will run
    at 19200 baud with an 8 MHz resonator.  With a 4 MHz resonator,
    the breadboard's serial port will run properly at 9600 baud, but
    the overall performance of the breadboard will be reduced.

 3. The name for the AVR programmer program referenced in the article
    ("PPPT") is different in the ZIP archive.  The development software
    uses a program named "AVR" instead.

 4. The Atmel assembler program (AVRASM.EXE) supplied with the ZIP archive
    is a 16-bit MS-DOS program which will (quietly) fail to produce
    any output files if the working directory path name contains any
    subdirectories with more than eight character names.  (Also, if the
    total path length of the working directory exceeds 64(?) characters,
    the program will also fail to produce any output files.)

 5. The AVR programmer program (AVR.EXE) supplied with the ZIP archive
    may fail to download the Atmel microprocessor reliability on certain
    fast, Intel processors.  A replacement program is available at

 6. We have had reports of problems using the parallel port programming
    tool (PPPT) under Windows NT, having to do with the program accessing
    the PC parallel port.  (Note: This program is named "AVR.EXE" in
    the development environment.)  This problem is being investigated.
    Symptom: The program cannot automatically find the programming cable
    and cannot be used to program the PicoWeb server.

 7. The README.txt file supplied with the ZIP archive failed to mention
    that the programming cable must be disconnected from the PicoWeb server
    "breadboard" in order for it to properly function as a network device.
    Instructions in the file "README.txt" has been changed accordingly.
    The firmware/Web page loading command file (formally LOADALL.BAT)
    has been broken into two parts (LOAD1.BAT and LOAD2.BAT) to provide
    for this step when downloading the breadboard version of the PicoWeb

 8. The files "define.h" and "base.html", supplied with the original
    ZIP archive should be changed to use bit 2 of the Atmel D-bus (i.e.,
    PD2) for the breadboard user-controlled LED (LED0).  An updated
    version of the ZIP archive with these changes can be found at

 9. We have had reports from the field of the Atmel microcontroller
    occasionally entering a "confused" state when a PicoWeb Server is
    power-cycled with the programming cable(s) attached.  In this state
    the Atmel microcontroller will repeatedly fail to download new
    firmware.  To correct this problem, unplug ALL cables from the
    PicoWeb server, wait a few seconds, apply DC power to the PicoWeb
    Server, then re-attach the other cables.