Consider, for the moment, the number of times ISP "programmer" problems arise in this forum.

Until there's a way to plug a commercial cable directly into the IC to be programmed, there will always be a need for a programmer schematic, since some means for making the interconnection must exist.

The fact that of the ~50+ different programmer/software combinations used (sometimes correctly) with ATMEL and likewise with Philips ISP devices at least one always seems to be a permanent fixture on this forum, it might be desirable for these manufacturers to take some relevant action.

First of all, I figure they could, and, therefore, should, publish a schematic and software that will program any and all of their programmable devices, past, present, a future. If one constructs such a circuit, exactly as specified then it should be reliable. If one substitutes 74HC245 for a 74HCT541, then he's on his own. He deserves neither the manufacturer's sympathy, nor ours.

I suspect that a circuit that does what I've suggested might be a might complex for the average kitchen-table operative, and, in fact, it might just be a mite too complex for me. Nevertheless, such a reference circuit should exist, even if only in documentation. From that, one should be able to divine the necessary hardware and software to effect programming of a given device.

We, the using public, should avoid any manufacturer which fails to document, fully, any programming procedure for any of their devices. If they don't tell you how to program a purportedly programmable device, then you should not buy ANYTHING from them.

It's YOUR choice.

RE