Low Cost EPROM programmer (Ben, this is for you)

Dave McGuire mcguire at neurotica.com
Wed Jun 18 08:21:24 CDT 2008

On Jun 17, 2008, at 11:53 PM, Seth Morabito wrote:
>> You should also be able to find a dirt cheap, piece of crap  
>> Chinese EPROM
>> eraser that will do the trick off of eBay for about the same price.
> I just bought one of these dirt-cheap, piece of crap Chinese UVPROM
> erasers on Friday.  It should be here tomorrow.  I'll let everyone
> know whether it's capable of erasing anything once I've given it a
> whirl!
> (My modern electronics buddies practically did a spit-take when I told
> them I was still working with UVPROMs!  The irony is, I'm only just
> now getting into this stuff, so 'still working with' isn't quite
> correct, either.  I'm perfectly happy to be stuck in the past!)

   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 McGuire
Port Charlotte, FL

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