On Jun 17, 2008, at 11:53 PM, Seth Morabito wrote: Eh, bunk. There's nothing at all wrong with EPROMs. Flash is *sometimes* more convenient, but not always. That said, though, all of my commercial design work lately has been with microcontrollers that have on-chip flash, and often no off-chip memory at all, EPROM or otherwise. I have a friend who repairs medical equipment, and sometimes he drops by with something he needs help with, usually a component-level repair. In that world, recently I've seen at least three or four boards made in the past couple of years (2006 copyright dates) with UV-erasable EPROMs on them. The machine I've been working with a lot lately (a wire-wrapped Z80 SBC with Forth and a bunch of peripherals) was originally designed for use with a 27C256, but I came across a tube of Hitachi 58C256 chips. My programmer (Data I/O Unisite) supports them, and it only took a minor wiring change (Vpp vs. A14) for it to work in my board. It saves the erasure step, but not really any time, because when doing heavy development I rotate through two or three EPROMs so there are always erased ones waiting for me. -Dave -- Dave McGuire Port Charlotte, FL