On Monday 15 Aug 2005 14:23, Jeff Carr wrote:
On 08/15/05 02:56, Paul Millar wrote:
Would people be interested, either in the software or in helping improve it?
I would. You said you built your own device, but I'm not a poor student (anymore). Could you guess which of the three on the mcmull page: http://www.mcumall.com/comersus/store/comersus_dynamicIndex.asp would be the closest to the schematic you used?
(three? only two on that page that I could see ....)
The closest is the "Dual Power Willem Universal EPROM Programmer".
This looks to be the same design: it has the same number of chips, in the same locations. The image quality isn't good enough to say more. Visually, the only difference between this one and mine is someone has mounted the linear regulator vertically to make space for the USB connected (just for its +5v line). Obviously, without schematics for the card, I can't say for sure.
The Enhanced Willem board looks quite funky and claims to be backwards compatible with the previous design, but I can't find schematics for it, nor any reference to it on the Willem pages: http://www.willem.org/
I was thinking of getting one of these (not so much of a poor student anymore), but without the schematics, it wouldn't be so much use.
I'd certainly be willing to make a go of it. If I can dig it up, there were some guys that wrote a parallel jtag interface to program amd flash. Maybe it would be useful. That was several years ago and the site seems lost in the annals of history now. Maybe you wrote that too :)
Cool. I'll stick the software somewhere useful.
Sadly, having fixed the regulator, I'm still stuck with the problem getting data off of the EPROM. I've tested the 4014 read circuitry (and software) by hot-wiring various EPROM-ZIF output bits to gnd or +5v and checking the output: this works correctly. Addresses are clocked in OK. Both /CE and /OE are low, yet the output is neither correct (well ... believable) nor consistent.
Ideas on how to debug this greatfully received.