How do I get my TOP2049 to read 8bit 32mbit chips?

XianXi

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Fixing some Neo carts and one of them has 4 x 32mbit V roms which run in 8 bit mode.

How do I get my TOP2049 to read these chips properly? It only supports 27C322 which is 16 bit or do the Neo V roms read in both 8 bit and 16 bit modes?
 
Hmmm, maybe I need a new programmer then.

Any suggestions on programmers that support 8bit 32mbit 42 pin mask rom reads?

I need one that does the usual:

27C4100
27C4002
27C800
27C160
27C322
27C1024
27C1000 (Without having to swap pins would be great)
27C1001/27C010
27C4096

Hell, if it can read 42-pin 64mbit mask roms, even better.
 
I have the TOP2049, but I am confused by you asking to read the IC in 8 bit mode. Are you looking to copy/dump what's on the IC or try to play the game through the programmer?
I don't know which IC your referring to but I believe the "reading in 8 bit mode" is done by the MVS hardware and wouldn't have an effect on the programmer trying to read the ROM data.

In general if a 16 bit PROM is written to only use the lower order bits up to the 8 bit address limit, then a programmer will copy it just as it is. Leaving the high order blank. I am keeping it simplistic in my description, there are a few other things involved too.
But I am sure someone on here will correct me if MVS has special PROM/ROMS that work differently.
 
I have the TOP2049, but I am confused by you asking to read the IC in 8 bit mode. Are you looking to copy/dump what's on the IC or try to play the game through the programmer?
I don't know which IC your referring to but I believe the "reading in 8 bit mode" is done by the MVS hardware and wouldn't have an effect on the programmer trying to read the ROM data.

In general if a 16 bit PROM is written to only use the lower order bits up to the 8 bit address limit, then a programmer will copy it just as it is. Leaving the high order blank. I am keeping it simplistic in my description, there are a few other things involved too.
But I am sure someone on here will correct me if MVS has special PROM/ROMS that work differently.

Hey Tronic,

Ya, I'm trying to verify the V roms that are 32mbit and I'm getting read errors where all the lower data outputs are all dead so I wasn't sure if it was the way it was reading or the mask rom is just bad.

Can you confirm that you are able to read/verify the 32mbit V roms in the TOP2049?

Thanks
 
Did you ever find your answer.

Not really. I just want to make sure the rom is reading correctly since the programmer is saying that all the low data outputs are dead or not connected. I just don't want to toss a perfectly working chip.
 
What do I select to read the 32mbit 8 bit 42 pin roms?

I'm afraid I don't understand your question. I always select the type of EPROM I have inserted into the ZIF socket. In the case of the EPROMs you listed, you put the adapter into the programmer's ZIF, then install the EPROM into the adapter's ZIF, per the instructions.

I just looked up the part numbers you listed in your OP on the compatibility list of the programmer I own, and they were all there (with the adapter).

BTW, looks like most of the devices you list aren't 8Mbit. 27C4100 & 27C4001 are 4Mbit. 27C160 is 16Mbit. 27C322 is 32Mbit...

You can download and install the software for it and try out selecting devices and looking at the interface, without having the programmer installed. I did before I bought it.
 
I'm afraid I don't understand your question. I always select the type of EPROM I have inserted into the ZIF socket. In the case of the EPROMs you listed, you put the adapter into the programmer's ZIF, then install the EPROM into the adapter's ZIF, per the instructions.

I just looked up the part numbers you listed in your OP on the compatibility list of the programmer I own, and they were all there (with the adapter).

BTW, looks like most of the devices you list aren't 8Mbit. 27C4100 & 27C4001 are 4Mbit. 27C160 is 16Mbit. 27C322 is 32Mbit...

You can download and install the software for it and try out selecting devices and looking at the interface, without having the programmer installed. I did before I bought it.

It might sound confusing.

The Neo Geo has 32mbit mask roms for the V roms which are read in 8 bit mode, my questions is, Will my TOP2049 programmer be able to read these chips properly if I choose the 27C322 as the chip type?

It probably got confusing when I was saying the 322 only reads in 16 bit mode so I was wondering if that would affect the read of the V rom which is usually read in 8 bit mode.

The only 2 V roms that I had I tried to read as a 322 and both showed that all the lower data lines were not connected so I wanted to know for certain that these V roms might be bad and wanted to eliminate the possibility that my programmer is reading them wrong because of the 8bit/16bit deal.

I hope that clarifies what I'm asking.
 
Hmmm, maybe I need a new programmer then.
Any suggestions on programmers that support 8bit 32mbit 42 pin mask rom reads?
I need one that does the usual:
27C4100
27C4002
27C800
27C160
27C322
27C1024
27C1000 (Without having to swap pins would be great)
27C1001/27C010
27C4096
Hell, if it can read 42-pin 64mbit mask roms, even better.

It might sound confusing.
The Neo Geo has 32mbit mask roms for the V roms which are read in 8 bit mode, my questions is, Will my TOP2049 programmer be able to read these chips properly if I choose the 27C322 as the chip type?

It probably got confusing when I was saying the 322 only reads in 16 bit mode so I was wondering if that would affect the read of the V rom which is usually read in 8 bit mode.

The only 2 V roms that I had I tried to read as a 322 and both showed that all the lower data lines were not connected so I wanted to know for certain that these V roms might be bad and wanted to eliminate the possibility that my programmer is reading them wrong because of the 8bit/16bit deal.

I hope that clarifies what I'm asking.

OK. I was replying to your 2nd post, asking about another programmer (other than the TOP).

Sounds like you're looking for something that reads & programs a device type OTHER THAN the ones you listed (27C4100,4002,800,160,322,1024,1000,1001,010,4096). 'Cause AFAIK all of those are 16-bit devices (except 1000, 1001, 010... but those are all 1Mbit).
 
Hey Tronic,

Ya, I'm trying to verify the V roms that are 32mbit and I'm getting read errors where all the lower data outputs are all dead so I wasn't sure if it was the way it was reading or the mask rom is just bad.

Can you confirm that you are able to read/verify the 32mbit V roms in the TOP2049?

Thanks

All I can do it confirm its definitely in the menu as a device it can read/program. I have no 322's to test out on, or I would give it a try.

I am pretty sure your mask IC's are just a method of muxing the data to the ROM, and not going to affect a programmer reading or writing to the ROM. The voltage to the pins still needs to be the same whether you are reading the data through a mask or not. In other words I am about 60% sure if the reader is saying the low order is bad, then it might be true. But this is because I can't look at the exact ROM's you have.

I was hoping someone else who has had experience with those ROMS would chime in. Can you try downloading the MAME roms for it and program a new set to see if it takes?
 
Can you try downloading the MAME roms for it and program a new set to see if it takes?

And that's thing, the 322's only run in 16 bit mode so I have to either build a multiplexing circuit to make them read as 8 bit or I have to split the V rom into two 160s.

The problem is the game I am trying to fix already uses all 4 slots for the V roms so I can't split any of them. I can use an SOP with a DIP adapter but like I said, I want to be sure these are bad chips before I spend $ trying to replace them.
 
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