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GROM part numbers for v2.2 console?

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This console I have is thought to be a v2.2, but when I look up the GROM part numbers they appear to be from the original console. I have CD2155ANL, CD2156NL, and CD2157NL.

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afaik GROM1 and GROM2 are identical. those are TI BASIC.
only GROM0 contains the v2.2 patch where the only difference is that they removed the check for ROM only cartridges. so only one of them should differ.

In the 99/8 sourcefiles it can be read that they actually got the approval to re-insert the check for ROM only cartridges, but they didn't have the time to do that yet, at least for the version of the sourcecode that is public.

that is why all 99/8 are not compatible with the Third party cartridges.

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afaik GROM1 and GROM2 are identical. those are TI BASIC

 

Yes. If you check the ROM files of MAME, the ti99_4qi.zip only contains one file (994qi_grom0.u29). The other GROMs are inherited from the parent driver ti99_4a.

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that is why all 99/8 are not compatible with the Third party cartridges.

 

I just played Defender on the emulated 99/8, gets listed as [D] FOR DEFENDER. Different stages of development?

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I just played Defender on the emulated 99/8, gets listed as [D] FOR DEFENDER. Different stages of development?

 

And on the emulated 99/4 and 99/4A QI it doesn't show?

Edited by kl99

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And on the emulated 99/4 and 99/4A QI it doesn't show?

 

Yes.

 

The 99/8 in MAME is essentially Ciro's 99/8, so maybe he can try.

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Remember: "QI" does not necessarily imply v2.2. I have at least two "QI" boards which are not v2.2.

 

That said, the GROMs are to the right of the CPU and the print is not clear in your pic. Can you do a close-up of them?

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here's something else i found:

 

"D. If most non-TI modules will not run

in the console, check the TI title
screen for a 1983 copyright notice. If
found, the console contains the TI
operating system which prevented use of
non-TI modules. This operating system
may be bypassed with some software
programs or aftermarket hardware
adaptors. Replacement of GROM 0 in the
console (chip number CD2155) with a chip
from an earlier production console will
replace the newer operating system and
permanently solve the problem."

 

ftp://whtech.com/articles/limanews/CONSOLE.TXT

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The chip I pulled from my v2.2 non QI console was labelled CD2155|8327MCFX|Philippines

 

The other groms have a different style for the second line: MFX 8249 or NFX 8249

 

Maybe this can be used to determine the vintage...

 

-M@

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There might be two ways to tell: are the older chips CD2155ANL or are they just CD2155NL? The "A" is key, as that usually indicates a revision. The other possibility is in that second line, as that may be the date the code was finalized and the chips were made: 8327= 27th week of 1983, which would be about right for the introduction of the V2.2 consoles.

Edited by Ksarul
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Ah, then the GROM0 on this board may indeed be a v2.2. When I looked last night at the two display consoles on my shelf they are simply CD2155. Now I just need to get this unit to power up to know for sure.

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