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Discussion in 'Now Playing - TV Show Talk' started by Peter000, May 11, 2014.
I'm on the fence. Thinking of bailing but feel somehow committed to finishing it.
Sort of like Under the Dome.
I haven't watched the latest yet but I'm amused by how they have like 12 lines...
and Cameron is madly scribbling more of the same, and Gordon looks at it on the white board and says, "THIS IS BRILLIANT!"
Um, guys, seeing what's going on in an algorithm in Assembler takes a LOT OF LINES.
Bedsides which the BIOS mostly has to interface with the hardware and the routines to do that will be common shared code and/or come from chip makers.
Frankly I think it not very good but I'll probably stick with it any way!
That's only partially true. If you booted an IBM PC without an operating system it would go directly into ROM BASIC. That's why the whole idea of clone PCs not actually copying the BIOS, despite what was written earlier about Phoenix, is pure BS. I owned plenty of them in back then, many with Phoenix bios. And every single one of them would give the error message about ROM BASIC missing if you forgot to put in a floppy with an operating system on it.
Not sure what you mean. The BASIC interpreter was not part of the PC BIOS. It *was* delivered by IBM embedded in the ROM alongside the BIOS, and as you said, if you didn't put in the PC-DOS floppy, it would default to the ROM BASIC prompt. The Wikipedia page on IBM BASIC has a good write-up of the various flavors.
But cloning the BIOS didn't include replicating the BASIC interpreter because it didn't need to. That component was a product of Microsoft, and was bundled into the non-IBM "MS-DOS" product. Since the BASIC was Microsoft's real product (before DOS!), you could just buy it. And Microsoft was happy to sell more copies!
The point is simple. If I'm reverse engineering the BIOS I'm going to insert a message such as, "Please insert operating system disk" or something similar. If I'm lazy and just copying the BIOS then I'm going to end up with the exact message that IBM has coded into their BIOS.
No, you're going to replicate the functionality 100%. Including the bugs and all user messages. The only notable exception being any mention of 'IBM' and the copyright messages...
Because if programmers are expecting behavior from the IBM PC, you want yours to be exactly the same. When there's a bug in the IBM BIOS, a developer would work around it (a BIOS upgrade for a bug fix in those days required a physical chip swap - this is before EEPROM "flashable" chips were installed). You want to make sure that workaround doesn't do something weird on your version as compared to the IBM.
Now, later in time, once the idea of "100% IBM Compatibility" is well-established and potential customers believe that compatibility, you'll see the BIOS implementations drift away from this rigorous replication.
An interesting side note regarding copying and copyright: A common practice among cartographers (map makers) is to insert short, fake / non-existent roads into their maps (typically a dead-end street so as not to screw up navigation). Then, if a competitor produces a map with the same fake road, you've got great evidence that they copied your work - as that's the only way that fake road would appear...
There's no OS running so there's no program running to expect any behavior to happen. The only functionality to duplicate is not functioning. It can be done using any message you want. It doesn't need to be the one lazily copied from IBM.
It's not just the program compatibility - it's the user expectations. In those days, the very idea of "IBM Compatibility" was THE issue, and customers needed to be assured that the machine was 100% functionally identical to the IBM PC (and yes, the ROM BASIC difference was noticeable and had to be explained to customers). People shopping for "PC clones" in those days would bring copies of Flight Simulator and other software along with them to test the compatibility for themselves.
There was no "laziness" there - it was replicated and matched on purpose because of those customer concerns.
I still call BS. On a real IBM PC you'd never see that message because ROM BASIC wouldn't be missing. You want to prove 100% compatible, don't show them a message that they'd never see with a real IBM PC. Show them actual ROM BASIC. No consumer would have ever expected to see that message and none would have ever demanded to see that message. Pure BS.
You can call BS all you want, but this IS how it happened and is a fact...
The message could appear on an IBM PC if the ROM BASIC chips weren't present. It was separate from the BIOS (and I had to look it up, but on the original 5150 PC model it appears to have been actually four chips, while the BIOS was contained in a 5th).
Since the clone makers knew they wouldn't include those chips, it would be simple to test the behavior on an IBM machine by removing them and documenting the results. So the message would have appeared on-screen, and that was then written down in the specifications passed to the clean room BIOS team as a functional requirement.
See, where we disagree is that the whole clean room stuff is true. I don't believe it. I believe they did their best to try to make it look that way. But to me their argument on this is just too weak to believe. If you buy the story, that's fine. It's too far fetched for me.
If the show didn't have Donna I probably would've bailed by now. The Joe character is no Don Draper, so if AMC is expecting a Mad Men of the 80s out of this then I think they need to find out how to focus on somebody else. Don is a creative person who can do a good job when the politics of his firm enable that. This Joe guy has nothing but pompousness and bluster that isn't backed up by any clue in what he's doing. Don has lots of sex, but I don't remember him doing it purely for manipulating people in business like we've seen Joe do twice already.
If the clean room stuff wasn't true it means they have copied the BIOS byte for byte. Even if IBM would have found 20 bytes the same at the same offset they would have proven the clean room thing wrong and would have had a case. They couldn't so the code was different enough to allow the clones to exist.
Sure, they might not have had a perfect clean room thing going, but they did rewrite the code themselves differently enough to allow all this to happen. Could they have changed the text of the message? Sure. Why didn't they? I don't know, maybe some applications used it to see if it was running on a genuine IBM PC or they were afraid it could be used for that and kept the text the same...
I sure don't know where this "Mad Men of the 80s" stuff came from, but I haven't read ANYTHING like that about this show. Far as I know, this show is uniquely styled for the subject...
C'Mon. They are going for the Mad Men vibe.
I can see them selling the show as Mad Men with a smaller cast and much cheaper budget.
What about them getting Joe beat up by the cops?
no. it's not that at all. unless you just think any period piece is that.
We also went to the moon. Really.
It's not too far fetched, in that it was done multiple times by several independent companies (and I work for one of them, and know many of the folks that did the work in those days - all retired now).
The show may be a bit light on detail as to what information can be used in the particular case of replicating the PC BIOS. But many, many things have been "reverse engineered" over the years. The BIOS was a bit different, in that it was software, and the concern is about copyright, not so much patents. Now, it certainly wasn't accomplished "in real life" by one person locked away in a closet over the course of a few weeks. There was a whole team of folks involved in those efforts.
The "clean room" folks can't look at the IBM source code (in any form), and to be extra careful, these teams didn't look at publicly available IBM documentation. There is a story of one new hire showing up for his first day of work - in preparation for his new job, he spent hours reading the IBM technical manuals - he was re-assigned to another role... So yes, they were being very careful to keep the clean room team out of anything to taint them.
A "dirty" team would look at the IBM machine, and would generate a functional specification - all the BIOS calls and functions - for the folks in the clean room to code up. So it wasn't so much a "black box" case trying to figure out what the thing does without a clue to the inner workings. The hardware was built from off-the-shelf parts, so making that all work was straightforward (I won't call it easy!).
See, I guess I don't consider that true reverse engineering. I see duplication of specific functions and bios calls differently than just figuring out how to make it work.