| Author |
 Topic  |
|
|
italie
3 Posts |
 Posted - 08/13/2005 : 00:33:01
|
I have everything working, parallel port is in eep, the hw test seems good, but every time i read a 2716 IC it comes up blank. no data anywhere. when I do a blank test it says the IC is NOT blank. anyone have any suggestions?
I have tried multiple 2716 IC's that should contain data. I'm not trying to write to them, so their shouldn't be a voltage problem, should there?
using winXP with portIO installed. |
|
| Reply #1
usb
138 Posts |
Posted - 08/13/2005 : 11:01:43
|
| The Enhanced willem does not support the low density NMOS EPROMs, such as 2716, 2732. |
 |
|
| Reply #2
italie
3 Posts |
Posted - 08/13/2005 : 11:40:44
|
Why is that? The markings on the board list it, as well as the proper voltages. Is there anyhting I can do to get it to work with them?
Unfortunatly it was the main reason I purchased this burner, to read the old 2716's, and the person I bought from assured me it would.
*edit*
I've gotten it to read them, by trying the pin 32 to 28 jumper trick. Well see if it can burn them, but reading was the most important thing for me.
If anyone else has any advice I would appreciate it. |
Edited by - italie on 08/13/2005 14:28:02 |
|
|
| Reply #3
usb
138 Posts |
Posted - 08/13/2005 : 14:48:58
|
Well, the initial design of Enhanced willem is included the 2716 support. But, the designer not considered the NMOS device need much higher current when it read/write time. So, basically there are no enough DC current when reading and writing.
Yes. You can do some modification on board so that can provide enough DC current. Such as you already did: short the pin 32 with pin 28. This will give the maximum working current to the 2716. However, the writing need a bit more complicated job to be done for the Vpp current. If you did that, you may want to share your modification with other users. |
Edited by - usb on 08/13/2005 14:51:04 |
|
|
| Reply #4
tardus
2 Posts |
Posted - 12/14/2005 : 20:56:23
|
| I also bought the Enhanced Universal Programmer version to program 2716s for some old pinball machines, I can read the 2716s with the pin32-pin28 jumper trick but that doesn't work for programing. Is it possible to get a schematic for this board to see if I can modify it? |
|
|
| Reply #5
italie
3 Posts |
Posted - 12/20/2005 : 22:12:52
|
Funny I should check back months later, and they are still hawking this peice of junk to people.
Tardus, buy another programmer. No schematics available on this one, and they are pretty much lying when saying this burner supports ANY EPROMS reliably. I fell for it by not doing my homework first, I know better now.
What I can't figure out is why they make this thing at all. Reads ok on occasion, but haven't been able to burn a single EPROM on it since owning it. It might have been good for parts had they not sanded everything down. The LEAST they could do is publish the schematics so we're not out the money we spent, and can up the current. |
Edited by - italie on 12/20/2005 22:16:11 |
|
|
| Reply #6
tardus
2 Posts |
Posted - 12/21/2005 : 19:41:38
|
| Italie, guess your right, I didn't do enough homework either. They say it's a current issue but I bent out pin 21 and connected it to a 25v supply that could provide enough current....and it still didn't work, so that may just be a smoke screen for other problems. Since I can't find a cheap programmer for a 2716 I'm building my own, already got 90% of it working for less that $10. |
|
|
| Reply #7
DL
USA
46 Posts |
Posted - 01/18/2006 : 17:24:41
|
I have modified several programmers (PCB3, Willem 4.0, Willem 4.5, ATH3.1SS) to support NMOS EPROMs by fixing the voltage drop. I used a relay; some fix it by driving the transistor harder and selecting a type with a lower saturation voltage.
I prefer the relay solution because the voltage drop is linear (vs. the non-linear transistor saturation voltage).
I haven't worked on a fix for the enhanced board. That board isn't really suited for programming EPROMs because there are no VCC options. Not to mention that there are no schematic or component diagrams available...
For the dual powered boards, I'd replace the step-up regulator with an LM317. That gives you a more solid VPP (don't need to worry about VPP dropping at a bad time), but you have to use an appropriate power supply and the USB power option is no longer available.
HTH,
Dennis |
Edited by - DL on 01/18/2006 17:26:59 |
|
|
| |
Topic |
|
|
|
Problem with reading 2716 and the enhanced
Forum Locked
