so i have about 20+ of these eproms that are verified as erased on my willem eprom programmer, but they wont program for some unknown reason. i have no clue what to do. does anyone want to test out 2 of these for me and tell me what i am doing wrong? i will send out 2 erased chips to someone and they can keep the chips, i just want to know what is wrong.
Maybe some of the bits can't be set to 0 (programmed). See what reads back when you try to program all data with zeros.
Prepare a file of all zero bytes and write this to the chip, then have the programmer dump the contents back to the PC. Verify that the data read back is the full size of the chip, and all zero.
ok, i dont know how to make a file of all zero bytes and i never dumped a file back onto the pc from a chip, any help on this would be great. also, what is this testing for?
An EPROM is composed of many bits that can be programmed to zero or one. You said that you verified that it was erased (all bits set to 1), therefore it appeared OK, but you couldn't successfully program it. My idea is that all bits in the erased state is no guarantee that they can all be programmed to 0, so you might also try setting them all to 0 and verifying that, in case any were "stuck" (sort of like bad pixels in LCD screens).
As for making a file of all zero bytes, I suggest you look into basic file editing tools and how data is stored in a computer system. Read up on
hex editors.
coinheaven wrote:
ok, i dont know how to make a file of all zero bytes and i never dumped a file back onto the pc from a chip, any help on this would be great. also, what is this testing for?
It sounds like you're not quite sure how to operate your programmer's software. What software are you using? How do you know your chips are erased? How do you know the programming of them is failing?
Also, from a unix prompt you can create a 256KB file of zeros with:
Code:
dd if=/dev/zero of=test.bin bs=1024 count=256
That is the easy way. If you are on a DOS based system, just get a hex editor and open a new file, and start typing 00's. After you have a few, start copying and pasting it repeatedly until you get up to 256KB's worth.
Coin, what Willem Programmer are you using? I know the USB ones are HORRIFIC! Lots of talk about this over on willem.org forum.
These kind of EPROMs must be verified that they are empty at 4.5v and programmed at ~6.5v (they operate at 5v). There are no willem programmers that can go down to 4.5v to do an accurate empty verification, and the USB ones only program at 5V!
Lastly, I hear the software has a build in tester. Set the pins as seen in the test H/W tab of the programming software. Then check all of them. Lastly, using a volt meter, check the voltage between ground (pin 16) and each one of the pins. They should all have a voltage!!
If you find any pins with 0v, that means the programmer is broken. (e.g. bad dip switch, bad logic ic, etc).
These willem programmers do work, but you really need to know how to fix them in order to maintain them.
I know that my Willem (Dual powered) wont program my PM29F002 Flash chips. (which is the same size as what you are trying, just a different setup)
The response on willem board was that I must have a bad chip. I tried a dozen chips and none of em worked so I'm more inclined to blame the programmer or its software. I also bought an external power supply and still no good. I had no problem with other (smaller) chips.
If anyone would like to suggest a good programmer for NES homebrew, I'd love to hear it. (EPROMS and Flash) I dont mind paying more for a good one.
Al
256KB=262144bytes
262144 bytes x 8=2097152 bits.
So, make a file with 2097152 zeroes. Copying and pasting is your friend.
I had to do this to make blank FDS images recently.
-Rob
albailey wrote:
I know that my Willem (Dual powered) wont program my PM29F002 Flash chips. (which is the same size as what you are trying, just a different setup)
The response on willem board was that I must have a bad chip. I tried a dozen chips and none of em worked so I'm more inclined to blame the programmer or its software. I also bought an external power supply and still no good. I had no problem with other (smaller) chips.
If anyone would like to suggest a good programmer for NES homebrew, I'd love to hear it. (EPROMS and Flash) I dont mind paying more for a good one.
Al
Did you test your programmer using a voltmeter and built-in test function? Good willem programmers have all their IC's socketed. One of them might have gone bad on you.
Quote:
So, make a file with 2097152 zeroes. Copying and pasting is your friend.
I kind of figured that you could just use a one-byte file and let the programmer mirror it, as I figure it has an option to do.
leonk wrote:
Coin, what Willem Programmer are you using? I know the USB ones are HORRIFIC! Lots of talk about this over on willem.org forum.
These kind of EPROMs must be verified that they are empty at 4.5v and programmed at ~6.5v (they operate at 5v). There are no willem programmers that can go down to 4.5v to do an accurate empty verification, and the USB ones only program at 5V!
Lastly, I hear the software has a build in tester. Set the pins as seen in the test H/W tab of the programming software. Then check all of them. Lastly, using a volt meter, check the voltage between ground (pin 16) and each one of the pins. They should all have a voltage!!
If you find any pins with 0v, that means the programmer is broken. (e.g. bad dip switch, bad logic ic, etc).
These willem programmers do work, but you really need to know how to fix them in order to maintain them.
I programmed other 27c020 chips ok, so i think the programmer is fine. So your saying that the chips might not be empty because the programmer cant do an accurate empty verification. Maybe i should erase them longer.
leonk wrote:
albailey wrote:
I know that my Willem (Dual powered) wont program my PM29F002 Flash chips. (which is the same size as what you are trying, just a different setup)
The response on willem board was that I must have a bad chip. I tried a dozen chips and none of em worked so I'm more inclined to blame the programmer or its software. I also bought an external power supply and still no good. I had no problem with other (smaller) chips.
If anyone would like to suggest a good programmer for NES homebrew, I'd love to hear it. (EPROMS and Flash) I dont mind paying more for a good one.
Al
Did you test your programmer using a voltmeter and built-in test function? Good willem programmers have all their IC's socketed. One of them might have gone bad on you.
I didnt try running any diagnostics. I'll give that a shot.
the offer is still open, if someone thinks they can figure out the problem. i have been swamped at work and havent had time to mess around with them.
I would be willing to try them. I have a Willem burner too.
You really need to study the datasheet a bit to use this burner. There's a reason more advanced burners make you select the specific chip/manufacturer, while Willem just has you select a generic type.. it's because you need to know what the chip wants and play around with the VCC jumpers. And like leonk was saying, you can't use USB power.
If that info doesn't help, my mailing address will be in your PM box and I could try burning one.
memblers, did you test them? have not heard back yet. please let me know if its the eproms or my programmer. thanks
Joe
Memblers wrote:
I would be willing to try them. I have a Willem burner too.
You really need to study the datasheet a bit to use this burner. There's a reason more advanced burners make you select the specific chip/manufacturer, while Willem just has you select a generic type.. it's because you need to know what the chip wants and play around with the VCC jumpers. And like leonk was saying, you can't use USB power.
If that info doesn't help, my mailing address will be in your PM box and I could try burning one.
coinheaven wrote:
memblers, did you test them? have not heard back yet. please let me know if its the eproms or my programmer. thanks
Joe
Memblers wrote:
I would be willing to try them. I have a Willem burner too.
You really need to study the datasheet a bit to use this burner. There's a reason more advanced burners make you select the specific chip/manufacturer, while Willem just has you select a generic type.. it's because you need to know what the chip wants and play around with the VCC jumpers. And like leonk was saying, you can't use USB power.
If that info doesn't help, my mailing address will be in your PM box and I could try burning one.
Where did you purchase them?
coinheaven wrote:
ebay
You probably got them from the same person I did (cant remember his name)
Are they AMD chips? None of mine would work or erase either. Then wanted to CHARGE me to replace them.
i got them from user "beachandantiques". they say they are erased, but they dont program. weird.
ok, so i figured out that my willem eprom programmer wont write 200 DC eproms. so how do i use a dc power supply instead of usb power? i tried to hookup a 12v adapter, but that didnt work. do i have to set the jumpers?
I had trouble with all the amd eproms that beach antiques sent to me too and I'm using a BP mircosystems programmer (wall plug power) and a willems programmer. Never did get them to work. They swore that they were good on their end but they replaced them for me anyway. The also sent me some other brand eproms in the original batch that worked great.
I used other amd eproms and have never had an issue so I don't know what to make of it. I don't think it was a power issue with my larger programmer.
coinheaven wrote:
ok, so i figured out that my willem eprom programmer wont write 200 DC eproms. so how do i use a dc power supply instead of usb power? i tried to hookup a 12v adapter, but that didnt work. do i have to set the jumpers?
Yes, if you look at the included jumper sheet you should see the jumpers listed on opposite side of the parallel port connection.
NC
damn, i lost that a while ago. can anybody help me out to set the jumpers? i have about 40 eproms that wont program, this would be a huge help.
Sorry for the lost 2 months.
I have the chips but my DC adapter's tip is loaned to someone who's out of town.. I'll get it back soon. I'm kinda needing it for other stuff too.
But most of the jumpers are labeled. The one to select USB or DC power is right next to the USB and DC jacks and is labeled. At least on my board, I dunno which one you have.
That jumper and the VCC voltage one are the only 2 I've ever needed to change, IIRC.
Yes!! It worked! all i had to do was change the jumper next to the dc outlet and the vcc jumper and used a 9 volt power adapter (the nes one). thanks for the help! so glad i can use these chips now>