27512 J-2 chip manufacturer EPROM questions operation wolf

[Womble]

So how much will it cost me to ship you my main board?

Rob

About US$60 each way airmail, surface mail is a bit cheaper but it goes by ship so can take up to 3 months each way. Probably more than the board is worth.

Can you take the sound board off and post a high res photo of the main board somewhere, it would need to be clear enough for me to read the makings on all the chips. I have a hunch....

What tools do you have? Soldering? Desoldering? What eprom reader?

 

[robgill2008]

Operation Wolf checksums soldering and UVPROM EMP-11

Hello Mr. Womble,
I have been real busy the last couple of weeks. I broke out my old kodak 4.00 megapixel camera out the other night, I could not get pictures that were worth a crap. I tried to use the scanner but because of the different heights it distorts the scanned image as well. I may try to find someone with a higher resolution camera and a tripod and send you the pictures in a couple more weeks. Isn't there someone here in the US that can do the same stuff you can?

to answer some of your questions, I have a soldering iron. However, I have seen my solder work and know that even with this old pcb technology that I would F*** something up.

As in my earlier posts, I have access to a Needman's EMP-11 chip burner. I checked four 27512 UVPROMs and the checksum was as the same as the checksum from the MAME roms. I also checked the two Mask ROMs against the MAME roms and got the same checksum value.

I know that all the little TTL 74XX chips are not what your interested in. I also figure that the few GALs and PALs are something your not interested in.

I will see what I can do for some pictures. Heck I know that the board may not be worth $120, but it may be worth that to me plus, I always like to learn...even the smallest bits of information can be helpful.

Thanks,
Rob

 

[dezbaz]

Hello Mr. Womble,
I have been real busy the last couple of weeks. I broke out my old kodak 4.00 megapixel camera out the other night, I could not get pictures that were worth a crap.

Thanks,
Rob

I hold the camera 4' from the item and zoom in keeping it level and square with NO flash in good or natural light

4MP should be good enough if you have a zoom

 

[Womble]

I am hoping to see what the SRAM chip layout and chip types are, there are on decent photos on the web of this PCB sadly. There's not much I can tell about TTL from a photo, same with PALs and GALs as they contain code that may or may not be intact, you can never read the code out again so you just have to hope they are OK, they usually are.

Your eprom burner is too old to be much use in this case I'm afraid, modern ones are far more than simply burners, they can test SRAM/DRAM, TTL and even act as frequency counters. I was hoping you would have one modern enough to test the SRAM chips on the board.

If you take a photo of the board in natural light with the board a 4MP should be fine, try to avoid using zoom with the shot, let the board fill the frame without zoom as often zoom on older cameras is digital zoom, i.e. you use fewer and fewer MPs as you zoom.

There are people in the US who can fix this stuff, but they may keep a low profile, its a niche hobby and if you are vocal that you do it you tend to get buried in requests. If you accept the requests you get absolutely buried in boards, many of which are not worth the postage. There are far more people with wrecked boards than there are who can fix them. Channelmaniac is the only US based guy I know who does this kind of thing but he is rebuilding his workshop at the moment so is not accepting any requests.

 

[channelmanic]

There's not much I can tell about TTL from a photo, same with PALs and GALs as they contain code that may or may not be intact, you can never read the code out again so you just have to hope they are OK, they usually are.

Some are readable... just depends on if they blew the security fuse on the PAL or set the security bit on the GAL.