Trying to write and test from eproms -am I just killin them?

Hello Guys,

My TOP853 came a few weeks back... I also purchased some ST M27C512-15f ICs (maybe these are the problem?). Currently for practice I just have an nrom from othello donor, and I'm trying to put Bomb Sweeper (homebrew) on it. I downloaded the rom, used famirom to break it it into png and chrs, I selected 512 since that's the chip I'm working with, I put the the chip into the programmer, load the bin, and write to the chip. in order to test the chip I'm attempting to do this this: http://nintendoallstars.w.interia.pl/romlab/nesock.htm I throw it into my nes system and turn it on. Nothing happens but a gray screen. I Also want to note that I have the cover off the Nintendo so I can just plug the board in without the cart and I noticed a flash come from the little window on a few of the chips, afterwards I tried placing them into my eprom programmer and it did not see a chip, I take it these chips are dead? Thanks for any feedback you can provide.

UVEPROM are really sensible (in luminosity and in tension), I hope you have other chips to test ?
Because high UV luminosity is needed to ERASE those, I would recommend you to hide the "window" with some sort of black cover.
It's common to see round black sticker in it, but you could use scotch + black paper.

Normally, if I'm not wrong, a programmer with his software let you check the EPROM after writing it.
Also if not, you could do a "reading" and compare the binary from the source.(there also tools for that, like hex-editors)
If you're not able to read it after writing it, this could be the problem.

Considering split, I remember using "Ucon64", which work pretty well.
Famirom should do the task, maybe check the size ?
BombSweeper.prg should be 16Ko (2^14 = 16384 octets) and BombSweeper.chr should be 8Ko (2^13 = 8192 octets)

It seems that "FAST & EASY EPROM TEST SOCKET" could be the issue : maybe you have some pins which are not in full contacts ?
If you have a multimeter, trace the pinouts from the expansion port to the EEPROM (resistances should be less than 1 ohm).
The wiki (if you haven't already checked) :
http://wiki.nesdev.com/w/index.php/Mask_ROM_pinout
http://wiki.nesdev.com/w/index.php/NROM
http://wiki.nesdev.com/w/index.php/NES_expansion_port_pinout

Regarding all of those things, I remember buying some EEPROMs which have half memory dead.

Hope this will Help You.

@Raccon,


Thanks for the tip.

I bought a lot of 27c512 ic chips (all diffrent brands) so I don't think its that. I've just desoldered the legs and set the ic chips in there and I get the gray box still. I take it I will have to solder it in place to know if it will work? or make a test cart? I realized that alter ego fits on nrom also so I decided to go with that for my reproduction. I used readnes3 to split it into a chr and prg, I then copied both files onto themselves until they added up to 64kb each (used copy /b, char was originally 8kb and prg was 32). I have everything right down to a T as far as I can tell. I also have verified the writes to the chip and I it confirms. Please advise Also I'll take some snap shots of the board, upload the files I'm using and tkae some screen shots of the steps I'm doing in the software... Thanks for replying

That's good. Just for you to know, EEPROM are better than UVEPROM and reprogrammables.


Absolutely, the best thing is to solder cheap electronic socket like this : http://www.futurlec.com/Sockets/ICS28.shtml
This will let you place and remove Eproms for testing, also adding an extra socket is a good tip (so there one soldered and one attached to an eprom wich could be more easily collapsed and removed with each other)

If you need to be helped for soldering materiels, just ask ?


I will look up