Strange Willem Programmer Problem

Strange Willem Programmer Problem
by on (#22402)
Hello everybody. Im still very new to the site (joined about 2 months ago) And first off i have to say thanks for everyone (especially tokumaru) Who helped me out on making some dev carts. I successflly made Super Mario Bros. 2 Jap version and this strange Super Contra 7. Got em both on some tsrom boards and everything worked great!

But my question is this>

1. It seems like everytime i program an Eprom For the first time it will have an error in it and stop programming, and kind ruin my eprom? Now i dont know if it is like really ruined, but basically will need to be erased before programming again. But this only happens the first time i open up the programmer to work

Now it has happened 3 times, like this. I mean the first time i ever tried to program it happened to my first eprom. Then i was like dang i must have something wrong, so i tried another one and it worked first try, and then another and worked first try. Anyways shut down, started it up a few days later. First eprom had error, and then the following ones worked great.

Anyways I Tried it tonight and first eprom had error, and then the rest of them programmed great????

Now i thought this was perhaps happening because maybe some of the eproms i had werent totally empty. But it seems like quite a coincidence when it happens first time i try it on a new day.

Any ideas anyone?

OH AND BY THE WAY IM USING THE WILLEM EPROM PROGRAMMER (THE $45.00 ONE, AND 27C4001 512 KB EPROMS. BOUGHT FROM EBAY.

by on (#22429)
Can you do a forced write (setting the software to a specific chip) without verify? Do that without a chip in the programmer the first time around, and you'll probably be good.

I'd say it's a small software glitch, but it could be hardware. I remember Pentium(1)-based packard bells had to have the i/o bit of the parallel port toggled twice before it operated normally with...anything except printers, really...

This is of course assuming that the Willem uses the parallel port...

by on (#22455)
ok yea it uses parallel port. So bascially load data and try to program chip without a chip in it? Then when it has an error. jut try it again with a chip in it? If thats what ya mean ill try that next time. thanks man!