Hi, I am trying to get the Shane Tolmie v9.30 bootloader working with my PIC 16F877A @ 20MHz and am encountering some strange problems. I am able to program the bootloader into the chip no problem. When I try to load the test program, I keep getting a "writing error". I sometimes also get a communication timeout error, but this is much less frequent. I keep doing this and eventually, I am able to complete the programming successfully. When it fails, which is most of the time, it fails at random points during the download. I have confirmed this same behavior on a second chip I have.
In despiration, I tried this same experiment with the Tiny Bootloader and had the same issue, fail most of the time, work once in awile. I looked at my serial cable on a Scope and it looked ok. If anything, the RS-232 data from the PC looked real good. The RS-232 data from the PIC was not ideal, its peak to peak swing was about 3 volts lower then expected. Also, the signals had a slope on them. The little I know about RS-232, my signal should be well within the operating range.
Is there any debug commands in the windows bootloader software I can use to further isolate this problem? Does anyone have any thoughts on what this could be? Thanks for your help.