We often say 1394 card, to be exact, it should be called 1394 standard interface card, and there are also 1394A and 1394B standards. For our video shooting, generally 1394a is enough. Therefore, there is no statement, we are talking about the 1394A standard 1394 card. 1394 card is a computer interface card. Since Win98, the system has integrated the standard drivers of 1394, so almost all drivers of 1394 cards come with the system. 1394 card has many functions, such as connecting 1394 hard disk, data transmission, video capture and so on. As a video capture device, the 1394 card needs the following design: 1. Stable power supply circuit ensures good compatibility of 1394 card. 2. Stable interface circuit to ensure image quality. 3. Anti-backflow design ensures that the current on the card will not flow back to the camera and burn out. 4. EMI circuit design to reduce the interference of computer electromagnetic waves on images. 5. Two kinds of interface design, that is, there are common 6PIN interface and 4PIN small interface. The main difference between the two interfaces is that the large interface can supply power and the small interface only transmits data. Generally speaking, the large interface is more used for connecting 1394 hard disk, and the small interface is more used for video shooting. From a security point of view, the small interface will better protect the camera because no current flows. If you buy a 1394 card in the market, the merchants will generally ask you whether you want it to be ordinary or better. If you say better, JS says dual chip is better. In fact, the dual chip is TI's 2-chip 1394 set (no other chips have dual chips), just like any 1394 chip. TI dual chip is the 1394 product with the longest life cycle of TI. Both physical layer and link layer chips have undergone many updates. I saw a lot of people on the Internet discussing which is better, single chip or dual chip. Many people think it's the same. According to my experience and application effect, I think there is no difference if it is used as the interface of storage devices, such as 1394 hard disk. If it is used for video capture or audio capture or playback, the effect of dual chip is better than that of single chip. As for why, it is hard to say, it is estimated that separate processing can better resist interference. The circuit design has the words "digital ground" and "analog ground", and the design of dual chips should actually be the same. I have compared the same camera with the same tape. I feel that the image of the dual chip is slightly fresher. When the image moves faster, the jagged edge of the image is less than that of a single chip. It is precisely because of the excellent quality of TI dual chip that it has been favored by many users and used by some unscrupulous manufacturers. TI dual chips have been updated many times since production, and the quality has been improved one by one, so remember: not all dual chips are good, and some dual chips are not only bad, but also have many compatibility problems. TI's latest and best dual chips are TSB 12LV26 (physical layer chip) and TSB4 1AB3 (link layer chip). Generally, TSB 12LV2 1 or TSB 12LV23, which has been discontinued for a long time, is used as the physical layer chip. The link layer uses TSB 12LV03 (also uses TSB4 1AB3, but this is a real chip). TI has already lost these chips, most of which were removed from old motherboards or foreign electronic waste, and the effect or quality is not guaranteed at all! Common fakes on the market: the so-called fakes are actually using a single chip as a double chip! Because only the single-chip package of TI is the same as the dual-chip physical layer chip (PHY) (the chip size and pins are the same), some illegal factories use a single chip to pretend to be a dual-chip physical layer chip, while the link layer chip is just a bad or useless chip, so many people look like dual chips, but they don't know that JS has made huge profits at this time, and consumers have spent money! Generally speaking, if you see TSB43AB2 1, TSB43AB22, TSB43AB23 on the dual chip, then this dual chip card must be fake! (these three numbers are the numbers of TI single chip microcomputer. Compared with single chip, TI dual chip is more complicated in design. Carelessness will lead to compatibility or instability. In many places, you must not cut corners like a single chip. For example, in the power supply part, the power is supplied directly from the motherboard with a separate voltage stabilizing IC, which is very unstable. Another example is the circuit and protection circuit of the interface part, which is also very critical. LZ friends, if tens of dollars is really not that bad, I suggest buying a slightly bigger brand product or going to a digital store specializing in video editing. They sometimes recommend products with high quality and low price to you. There are also many acquisition cards with comprehensive functions, such as Bi Ru with TV coordination or output, as the case may be.