|T O P I C R E V I E W
||Posted - 10/23/2007 : 18:33:44
Hi' I'm fairly new at this - I am trying to read a 27c512 chip (EEprom from a VW - JL27C512E. It seems to read alright and fills the buffer, but when I then attempt to verify I get chip read differences at random locations. Succesive read / verify attempts give different compare error locations. Is there a problem with XP printer ports? Hardware check always indicates good! I did read on one of the forums that the red and green lights should go out when the software is loaded? Mine are on all the time.
|2 L A T E S T R E P L I E S (Newest First)
||Posted - 10/26/2007 : 12:18:08
quote:If VPP is enabled while reading the data, you could end up programming your EPROM (unintentionally).
Originally posted by RKenney
Is there a problem with XP printer ports? Hardware check always indicates good! I did read on one of the forums that the red and green lights should go out when the software is loaded? Mine are on all the time.
When the program is running and in synch with the programmer, only the PWR LED should be on unless you're reading or writing. VPP should only be on when you're programming.
There's a registry edit that disables printer port polling in WinXP. It stopped working for me around SP2 and I had to disable legacy plug/play support on the printer port to stop polling. Polling will randomly enable VPP and VCC. I had dozens of devices programmed by accident before I found out about disabling plug/play support. It would be nice if all Willem type programmers had a VPP disable feature...
||Posted - 10/24/2007 : 08:14:54
check pin contat and try using a external power.