1024 eprom problem. can some one with an eprom burner please help?

i have 2 brand new eproms i bought to flash the unibios to with some old eprom hardware a flasher and uv eraser.
some reason they did not work even after many erases in the uv light.
the funny thing is i had a bios i bought from massystems many years ago.
they covered the window with black marker and scratch the chip info off.
i got all the marker off and from what writing i could see on the chip i got the needed info to flash it correctly.
so now my aes has the latest unibios

i have a mvs i would love to put the bios in and 2 blank eproms.
2 eproms i have are ST 27c1024-120
SGS Thomson was renamed to ST micro electronics.
the eprom software i had only had SGS and it would not work as with many other random guesses.

can some one please help me out?

The manufacturer shouldn't really matter as long as it is a 27c1024. After you blanked the chips with your eraser, did you use the software to check if it was actually blank?

When you inserted the chips was the software already running? I know with willem, inserting the chip before opening the software can cause random writes, forcing me to reblank the chip. How long did you leave the chips under you eraser? Is the bulb in your eraser fairly new? My eraser said that after about 1000 hours of use it was 50% effectiveness of a new bulb, requiring much longer exposure time for a complete erase.

What sort of programmer do you have?

-DT

it was a while ago that i used the eprom hardware. it was lent to me from a friend of a friend. i left the chips in for a many durations from a hour to a full night.
i never got any real correct feed back from the eprom.
the same hardware had no problem erasing and burning the chip i got from massystem and that chip was 5+ years old. these chips are brand new.
they may be defective. i was hoping some one could try and flash them for me.
the programer is a flex-700, all-07

What is the actual problem here? Does the programming fail or are they programming ok and simply not working in the NeoGeo. If it is the latter I expect the problem is that the programmer software is changing the data (ie its wordswapping it). Simply make sure its writing the data as bytes to be sure.

Raz

the programer will just fail with the 2 eproms. so i have 2 bad chips or the eprom hardware will not work with that make of eprom chip..

Did you verify that the chips were blank with the programmer before you tried burning them?

One thing it may be worth doing is a little searching on the net for some specific info on the eproms - I have fallen foul of this one !!!

I have an Olympia Vega board (don't bother searching it is not exactly common !) and I wanted to dump the eproms ..... a few tms2516 and tms2532 ..... similar to 27c series but have a couple of pins swapped round ...... after many attempts at reading I discovered that tms2516, etc are actually the same as everyone's 27c16's .... and different from everyone else's 2516 !!! deep joy !

Moral of the story .... don't believe the writing on the chips !!! lol

Iain

i dont have the eprom hardware any more to check the eproms.
but if any one would like a shot at flashing it for me i would be very thankfull.
of the 2 chips you can keep one for your self and or we could work on something else.

You can drop me an email - jmkurtz@columbus.rr.com. I can check them for you.

Jeff