Hello Peter,
Andrew is correct in that the S4 is not able to generate voltages lower than 5v.
I can however offer you a solution: the Dataman-40Pro.
The 40Pro is one of our lowest cost programmers. As its name suggests it is specialised in supporting memory devices. A full device support list and the full product specifications can be found on our website
www.dataman.com
The 40Pro is a PC based USB programmer which supports over 24,800 devices(08/2010). It comes with all the cables and software needed to start programming straight out of the box. The software is updated on a monthly basis.
Specifically, the feature that will help you is the "Generic-EPROM" selection. Simply select a device of the correct size from this catagory and you will then be able to modify the following parameters:
As you can see, the VCC voltage can be set anywhere from 2-7v and you can also tweak the current values and basic timing parameters in order to try and get a good read from a device.
The 40Pro is available from stock and comes with a 3 year warranty as standard. We also offer a 30 day money back guarantee, so if the programmer doesn't do what you need, simply return it for a full refund.
If you have any questions, please do not hesitate to contact me.
Best regards
Neil Parker
Dataman Programmers