1st W7 RTM build 7600.16384: Did MS named it cause They like the nos?


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Some time ago a friend had told me there was no build 7200 in the winmain branch, because the build no. 7200 was reserved for RTM, and win8(or whatever MS would name it later, so ATM we just have to call it win8) was started from build 7301, and will RTM at build 8000.

I had read something like it on WZOR for the build 7200 reservation, then later everybody was predicting RTM is 7300. It came as quite a surprise when RTM was actually 7600.

Recently I learned from another friend on the concept, it seems MS simply had no other better choice than to name the RTM as 7600. It all started with Vista, The Windows QFE Team(Quick Fix Engineering) had reserved the final 4 bits of the binary build string as indications of Service Packs, thus, SP0(i.e. the RTM itself) is [0000]. There are 16 combinations, so there can be 15 Service Packs(7601 thru7615) to fill the available slots, naturally nobody would dream of having so many Service Packs for a single OS.

Then, for a reason beyond my understanding(I am no developer, nor have any interest in it), this caused the necessity that the RTM number has to be a multiple of 16. Furthermore, MS has the tradition to round-up RTM numbers to 100's, so the first candidate for the win7RTM in the 7xxx region would be 7200. MS might have reserved this number for RTM, but had thought better of it, because it is awkward to have the RTM evolved from a earlier build bearing the numbers of 726x.

Now, 400 is the minimum 100-rounded 16-multiple, so after 7200, 7600 is the next candidate, and the next one is 8000. MS would hesitate to use 8000:

- They probably prefer to leave 8000 and 8xxx's for win8.

- Windows API GetVersion could only support the max. build number of 16383(1 number below 2^14), MS may want to leave more room for the later OS's.

- The current softwares can only support 4-digit build numbers, it's something like the 2K bug. If MS could push the requirement of 5-digit build numbers further back, let the software guys to develope 5-digit build number supporting softwares, then by the time a 5-digit build comes out, the "4-digit build only" softwares should all have become deep-buried fossils.

Therefore, MS probably had no choice, they just have to use 7600 as RTM, but compiling a 7600 could be voted down and they couldn't compile another 7600 as next candidate, that's what the "minor builds" come into play.

Now, the QFE sets another condition, in order for HotFix to validate, the first(minimum) minor build number must have the value of [1] for the 14th bit, i.e. the number has to be 2^14(2 to the power of 14) ,i.e. 16384. Therefore, for Vista, win7,win8...., until this system was changed, the minor build number just has to be 16384, and then the next minor build numbers has no further conditions, it could be any number larger than 16384.

So, the first RTM of win7 just has to be 7600.16384; and the next interesting question is: What about windows 8??

Some people had said that win8 couldn't have started when win7 was not RTM, then please note these facts:

- Vista was developed in 5 years, when XP RTM, Vista was almost beginning it's mid-phase of development.

- Win7's first known build was 6.1.5025.winmain.050111-2030; when Vista was RTM in Nov. 06, the nearest known builds(before and after) of win 7 were:6.1.5729.0.winmain.060914-1613 and 6.1.6415.0.debuggers(dbg).070404-1234.

If according to rumor, win8 was developing builds in the 73xx range, if MS wanted to have win8 RTM at 8000, they need to proceed within this range, there is no rule against it, but it would be very awkward to develop new build numbers smaller than 7600.

If they were to start the next win8 build with numbers beyond 7615; than it would be most unlikely that it could RTM at 8000, there is simply too little room to do that.

Personally I would speculate that, just as in the case of win7, win8 would Beta on 8000, the next RTM number candidate would be 8400; but I thought it would be the better choice of 8800.

Edited by FaiKee
Personally I would speculate that, just as in the case of win7, win8 would Beta on 8000, the next RTM number candidate would be 8400; but I thought it would be the better choice of 8800.

:)

nice, thank you for the write up. makes total sense if you are a nut head, ;). very nice.

On 2nd thought I edited the part about people doubting win8, just didn't want to start another fight. :rolleyes:

Absolutely. Mate, it's seriously time for you to have a break. You've been reporting every single thing thats happened with Win7 for months now, reckon it's time to look at other pursuits? ;)

Yeah, starting as of to-day(after this little discussion I mean) I am getting my life back LOL. :laugh:

As I said, I am stuck with 7100RC until the retail comes out, so I wouldn't care about wtf about RTM leaking.

FaiKee: 7600 could be a relative ratio : distance Earth to the Moon divided by 40 years calculated on the 20th July over the sum of the first 16 prime numbers...only through this tiny Window RTM will occur....

Eco must be ROTF on this one (Foucault's Pendulum)

Reserving the lower nybble for SP identification makes a lot of sense, actually, and sounds like something that MSFT would do. And it does explain their W7 version numbering. How they chose the subbuild number (start at 0x4000, or 16384, and just work up) was apparent back when Vista first came out.

Just one nit, though: the valid range for build numbers is 0-32767 (only the first bit of GetVersion()'s high-order word is reserved; not the first two bits).

Edited by code.kliu.org
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