Situation with this parallel programming becomes worse and worse, since most manufacturers decided not to publish parallel programming timing schemes for ISP/IAP programmable micros any longer. Only well established manufacturers of professional programmers get this information. The quite clear reason for this is, that customer shall be softly forced to switch to ISP/IAP programming or at least use a reliable programmer!

So if you build your kitchen table programmer, you will be forced to use chips that probably will be discontinued soon.

Editorial:
Manufacturers have lost customers because the design engineer in his early days used a kitchen table programmer and blamed the chip manufacturer for whatever went wrong (short lived data retention - a missed bit - who knows what). That design engineer based on his early experience decided "I'll buy brand x when hell freezes over".

A guess:
Atmel reasoned "we will publish a working programmer to avoid this situation" - too bad they forgot to maintain it. Philips decided "we will not publish programming information". Who did the right thing from a marketing perspective? I don't know.

Erik