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atrax27407

EVEN Byte console ROM

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It is actually to figure out which of the two console ROM chips is for the even bytes on a QI console so that a modified chip will land in the correct socket. . .

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Haha, looks like I got the question wrong.:roll:

(Okay, do-over)

 

Looking at the QI schematic... U3, connects to DATA LINES CD0 - CD7(odd), while U5 connects to DATA LINES CD8 - CD15(even).

Any better?:lol:

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U3 is the odd byte ROM and U5 is the even byte ROM. Is that for the standard console or the QI version (which has the motherboard revised)?

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3 minutes ago, atrax27407 said:

For reference, where are the EVEN and ODD byte ROMs on a standard console.?

 

Even byte is U610 (parallel to the TMS9900). Odd byte is U611 (perpendicular to the TMS 9900).

 

...lee

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If you have a look inside the ROM sets of MAME (ti99_4a.zip), you will see that I named the files according to the socket of the ROM.

 

$ unzip -t ti99_4a.zip    
Archive:  ti99_4a.zip
   testing: 994a_grom0.u500          OK
   testing: 994a_grom1.u501          OK
   testing: 994a_grom2.u502          OK
   testing: 994a_rom_hb.u610         OK
   testing: 994a_rom_lb.u611         OK
No errors detected in compressed data of ti99_4a.zip.

 

However, I did not do this for the QI, as the ROMs are identical except for GROM 0, and the other ROMs are taken from the "parent" system (ti99_4a.zip).

 

$ unzip -t ti99_4qi.zip  
Archive:  ti99_4qi.zip
   testing: 994qi_grom0.u29          OK
No errors detected in compressed data of ti99_4qi.zip.


 

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