I have an old EPROM programmer (M2L Electonics EZEP), but it only works with DIP packages. After browsing their site http://www.m2l.com I saw that they have a PLCC adapter for US$60. I thought this was a little steep, and seeing that DIP and PLCC version of the BIOS chip map pins 1-32 the same, I decided to build my own.
I got a little piece of perf board, two strips of 16 pin single row headers and a 32 pin PLCC socket. After wiring pins 2-32 of the headers to pins 2-32 of the PLCC (pin 1 is NC) I had a working adapter.
The EZEP didn't have the 39SF020 listed, so I found the Atmel 29C020 and 49F020 have similar specs. I was able to sucessfully read and write using this combo.
I hope this helps someone out.