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EX800 EPROM file corrupted in Files section ?

EX800 EPROM file corrupted in Files section ?

2013-06-26 by benoitdmx

Hello guys,

I started some investigations on the EX800 firmware, and I tried to disassemble the binary file located in the Files section (EX800 firmware)

As far as I can see, the file is corrupted : the first bytes are 06 B9 for address 0x0000 (the reset vector). And there are no instructions with 0x06 prefix in the 8085.

I will try to compare the file with the EPROM content in my EX800, but if somebody already made another dump and can compare it too...

Benoit

Re: [korgpolyex] EX800 EPROM file corrupted in Files section ?

2013-06-26 by Gordon JC Pearce

On Wed, Jun 26, 2013 at 12:35:48PM -0000, benoitdmx wrote:
> Hello guys,
> 
> I started some investigations on the EX800 firmware, and I tried to disassemble the binary file located in the Files section (EX800 firmware)
> 
> As far as I can see, the file is corrupted : the first bytes are 06 B9 for address 0x0000 (the reset vector). And there are no instructions with 0x06 prefix in the 8085.
> 
> I will try to compare the file with the EPROM content in my EX800, but if somebody already made another dump and can compare it too...
> 
> Benoit

Isn't the CPU little-endian, making that address $B906 and therefore quite firmly in the ROM map?

I know the EX800 image from the files section works because that's what I use in my Poly...

-- 
Gordonjcp MM0YEQ

Re: [korgpolyex] EX800 EPROM file corrupted in Files section ?

2013-06-26 by Michael Hawkins

It is not corrupt.

06 B9 is mvi b, 0B9h


Mike



________________________________
Show quoted textHide quoted text
 From: benoitdmx <benoit@...>
To: korgpolyex@yahoogroups.com 
Sent: Wednesday, June 26, 2013 8:35 AM
Subject: [korgpolyex] EX800 EPROM file corrupted in Files section ?
 


  
Hello guys,

I started some investigations on the EX800 firmware, and I tried to disassemble the binary file located in the Files section (EX800 firmware)

As far as I can see, the file is corrupted : the first bytes are 06 B9 for address 0x0000 (the reset vector). And there are no instructions with 0x06 prefix in the 8085.

I will try to compare the file with the EPROM content in my EX800, but if somebody already made another dump and can compare it too...

Benoit

Re: EX800 EPROM file corrupted in Files section ?

2013-06-26 by benoitdmx

Ok thanks Mike

It means that my 8085 disassembler is... humm... (it reports this sequence as unknown instruction... like most of the RST vectors entries). I did not check in the datasheet to be honnest, just trusted the software

I will try another disassembler then (for those being interested : the problem I saw comes from DASMx. It worked perfectly to disassemble the 6303 code from my DSS1... but clearly not the case for the 8085)

Is there a 8085 disassembler you would recommend Mike ?

Benoit


--- In korgpolyex@yahoogroups.com, Michael Hawkins <korgpolyex800@...> wrote:
Show quoted textHide quoted text
>
> It is not corrupt.
> 
> 06 B9 is mvi b, 0B9h
> 
> 
> Mike
> 
> 
> 
> ________________________________
>  From: benoitdmx <benoit@...>
> To: korgpolyex@yahoogroups.com 
> Sent: Wednesday, June 26, 2013 8:35 AM
> Subject: [korgpolyex] EX800 EPROM file corrupted in Files section ?
>  
> 
> 
> Â  
> Hello guys,
> 
> I started some investigations on the EX800 firmware, and I tried to disassemble the binary file located in the Files section (EX800 firmware)
> 
> As far as I can see, the file is corrupted : the first bytes are 06 B9 for address 0x0000 (the reset vector). And there are no instructions with 0x06 prefix in the 8085.
> 
> I will try to compare the file with the EPROM content in my EX800, but if somebody already made another dump and can compare it too...
> 
> Benoit
>

Re: EX800 EPROM file corrupted in Files section ?

2013-06-27 by benoitdmx

Ok, I found what was wrong with DAMSx. The problem was between the chair and the computer....

I just declared vectors in place of RST entries at beginning of the symbol file. So DAMSx interprets the data at address 0x0000 as a jump to address 0x06B9...

In fact, RST are not vectors for the 8085, they are entry-points, and the symbol must be different in the table for DASMx.

I just updated my symbol table and now, the EPROM file is disassembled correctly.

Benoit 

--- In korgpolyex@yahoogroups.com, "benoitdmx" <benoit@...> wrote:
Show quoted textHide quoted text
>
> Ok thanks Mike
> 
> It means that my 8085 disassembler is... humm... (it reports this sequence as unknown instruction... like most of the RST vectors entries). I did not check in the datasheet to be honnest, just trusted the software
> 
> I will try another disassembler then (for those being interested : the problem I saw comes from DASMx. It worked perfectly to disassemble the 6303 code from my DSS1... but clearly not the case for the 8085)
> 
> Is there a 8085 disassembler you would recommend Mike ?
> 
> Benoit
> 
> 
> --- In korgpolyex@yahoogroups.com, Michael Hawkins <korgpolyex800@> wrote:
> >
> > It is not corrupt.
> > 
> > 06 B9 is mvi b, 0B9h
> > 
> > 
> > Mike
> > 
> > 
> > 
> > ________________________________
> >  From: benoitdmx <benoit@>
> > To: korgpolyex@yahoogroups.com 
> > Sent: Wednesday, June 26, 2013 8:35 AM
> > Subject: [korgpolyex] EX800 EPROM file corrupted in Files section ?
> >  
> > 
> > 
> > Â  
> > Hello guys,
> > 
> > I started some investigations on the EX800 firmware, and I tried to disassemble the binary file located in the Files section (EX800 firmware)
> > 
> > As far as I can see, the file is corrupted : the first bytes are 06 B9 for address 0x0000 (the reset vector). And there are no instructions with 0x06 prefix in the 8085.
> > 
> > I will try to compare the file with the EPROM content in my EX800, but if somebody already made another dump and can compare it too...
> > 
> > Benoit
> >
>

Re: [korgpolyex] Re: EX800 EPROM file corrupted in Files section ?

2013-06-27 by Michael Hawkins

Check out my hawk800 sourceforge project. I just uploaded the disassembler I used back in 2007 and also provided the supporting files that will give you all of the disassembly labels and comments that I worked out back then.

Read the README.txt file.

https://sourceforge.net/projects/hawk800/files/Disassembly/


Mike



________________________________
 From: benoitdmx <benoit@...>
To: korgpolyex@yahoogroups.com 
Sent: Wednesday, June 26, 2013 4:11 PM
Subject: [korgpolyex] Re: EX800 EPROM file corrupted in Files section ?
 


  
Ok thanks Mike

It means that my 8085 disassembler is... humm... (it reports this sequence as unknown instruction... like most of the RST vectors entries). I did not check in the datasheet to be honnest, just trusted the software

I will try another disassembler then (for those being interested : the problem I saw comes from DASMx. It worked perfectly to disassemble the 6303 code from my DSS1... but clearly not the case for the 8085)

Is there a 8085 disassembler you would recommend Mike ?

Benoit

--- In korgpolyex@yahoogroups.com, Michael Hawkins <korgpolyex800@...> wrote:
Show quoted textHide quoted text
>
> It is not corrupt.
> 
> 06 B9 is mvi b, 0B9h
> 
> 
> Mike
> 
> 
> 
> ________________________________
>  From: benoitdmx <benoit@...>
> To: korgpolyex@yahoogroups.com 
> Sent: Wednesday, June 26, 2013 8:35 AM
> Subject: [korgpolyex] EX800 EPROM file corrupted in Files section ?
> 
> 
> 
> Â  
> Hello guys,
> 
> I started some investigations on the EX800 firmware, and I tried to disassemble the binary file located in the Files section (EX800 firmware)
> 
> As far as I can see, the file is corrupted : the first bytes are 06 B9 for address 0x0000 (the reset vector). And there are no instructions with 0x06 prefix in the 8085.
> 
> I will try to compare the file with the EPROM content in my EX800, but if somebody already made another dump and can compare it too...
> 
> Benoit
>

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