Garberstreet Electronics wrote:
< I use the Willem Eprom programmer. Really cheap, < and works very well. Here is a link to the one < like I have for $16.< < http://tiny.cc/jJmYz >
Amazingly, the same seller has the same device for $18.00, and $29.45, as well.
That looks like the Sivava programmer I paid $85 for last year. It basically works, but don't expect even a reply to any e-mail you send him, much less any support for the unit.
The documentation is a complete mess and didn't exactly match the unit I received.
He modifies the board design and the Willem software and does not disclose the differences. This caused a lot of backlash in the Willem online community.
Don't be fooled by the USB cable. The unit tries to get DC power from USB and does not communicate over it. The interface is strictly parallel port. As a practical matter, you are better off running it from a wall-wart anyway.
Saved the best for last: There were a lot of shortcuts taken with the hardware implementation. Primarily, it uses a DC-DC converter to derive 21.5V Vpp for older EPROMs (such as 2708, 2716 and 2732). There are known problems with this and you may end up with devices that either won't program or which verify after programming but decay quickly due to insufficient voltage. Basic issue is voltage drop across the transistor used to switch Vpp.
I ended up doing a custom hardware mod on mine to work around this, but it was more trouble than it was worth.
After putting up with the unit for almost a year, I decided life was too short and bought an Andromeda Research unit, which handles anything I need to program and is extremely well supported (comes with complete schematics and service information as well).
Caveat Emptor. Steve