Xeltek Superpro 280U is a fine USB programmer. Its downsides I encountered are so far only in the software part. The ones encountered are listed here:Annoyance 1: The software is Windows-only. Annoyance 2: There are more variants of the Intel HEX format. Gpasm from gputils produces Intel HEX 32 format by default.
Xeltek software swaps the bytes when fed with such 32 and 16 bit format, requiring the "-a inhx8m" option.Annoyance 3: When writing code, it is needed to write new versions of the code into the
chip. This requires reload of the hex file before starting the programming. The software has a comfortable "auto" function, which can combine the erase-program-verify, but does not allow automatical reload of the code file. A workaround is using some automation tool. AutoIt v3 was used here, with this file as a macro.