sic@ritcsh.UUCP (Eric A. Neulight) (01/05/89)
In article <174@wa3wbu.UUCP> john@wa3wbu.UUCP (John Gayman) writes: > > Can anyone give me the low-down on what the difference is between >QIC-02 and QIC-36 tape drives ? I'm looking for the mechanical differences >if any and the operational differences. What would the the advantages >and disadvantages of one over the other ? You see both formats mentioned >all the time but never any discussion of what its all about. I'm sure >many would like to know. Thanks. > Lately I was donated two QIC (Quarter Inch Cartridge) tape drives, and I am creating an intelligent general-purpose interface to them. However, when I received them, they came with no documentation, and the company that created them has no clue as to what customer support and good PR is. They would not even think of selling me any interface or tech manuals on them, even though they stopped producing the thing nearly two years ago. I had to assume that even though the SOBs weren't so friendly, that they were at least smart enough to create a QIC drive that met some sort of standard. It so happens that I was able to gleen a little info from stuff printed on the drive. It follows the ANSI standards: QIC-36 QIC-02 QIC-24 and one other I cant remember. In answer to your question, the differences are quite elementary.... If you have just a bare-bones tape drive (i.e., just the mech and electronics to spin the tape and read & write streaming bits) chances are that the interface on the back end is QIC-36. It is very basic, it understands spin forward, spin backward, read, write, heres a bit, theres a bit, tape in, tape write protected, etc. The next step up is some kind of semi-intelligent add-on, hence QIC-02. This is usually a piggy-back board to the drive (or a controller in your PC). I say semi-intelligent because the hardware bus protocol to the QIC-02 interface is convoluted as hell for modern microcontrollers, obviously committied to death, but it gets the job done. It has an 8-bit data path with a myriad of control lines and understands things like, read & write blocks for a whole file, read & write file mark, rewind, erase, etc. It does make things much easier than talking QIC-36 style. I was fortunate to have such interfaces piggy-backed to the drives I got. QIC-24 is just the actual recording format laid down on the tape. My descriptions above are quite simple for expediency, but all of these interfaces are ANSI standards, and are freely available to the public as such. I tracked down the bureau that distributes all the QIC info and had them send me all the descriptions and other pertinents. I am not near my desk right now so I can't supply the phone number, but call ANSI in New York City and find out the number of the place in California that distributes the QIC proposals. Hope it was edifying..... Eric ============================================================================== CLAIMER: Well -- I wrote it! Eric Alan Neulight "Nothing is Impossible -- Just Impractical." Electrical Engineering "For every Lock, there is a Key." Computer Science House "INSANITY is just a state of mine." Rochester Institute of Technology BITNET: EAN4762@RITVAX UUCP: ...!rutgers!rochester!rit!ritcsh!sic ==============================================================================
jlohmeye@entec.Wichita.NCR.COM (John Lohmeyer) (01/08/89)
In article <833@ritcsh.UUCP> sic@ritcsh.UUCP (Eric A. Neulight) writes: ... stuff deleted ... > It follows the ANSI standards: > QIC-36 QIC-02 QIC-24 and one other I cant remember. ... stuff deleted ... > , but >all of these interfaces are ANSI standards, and are freely available >to the public as such. I tracked down the bureau that distributes >all the QIC info and had them send me all the descriptions and other >pertinents. I am not near my desk right now so I can't supply the >phone number, but call ANSI in New York City and find out the number >of the place in California that distributes the QIC proposals. > The QIC "standards" are NOT ANSI standards. There is a considerable difference in the process used to create ANSI standards from the process used to create QIC standards. (ANSI standards must follow a process that guarantees there is a consensus on the standard and that all meaningful points of view have been addressed. QIC standards are developed by a group of manufacturers who pay significant sums of money to participate.) ANSI does know the QIC phone number, because they get many mis-directed phone calls. Perhaps I can save you a little time: The QIC standards were developed by an organization known as Freeman Associates (Ray Freeman) and I believe it is located in Santa Barbara, CA. BTW, there is an ANSI standard based on QIC-02 that was recently published. I believe it is called something like "Streaming Cartridge Tape Devices" and it should be an X3 standard with a number greater than X3.140. John Lohmeyer jlohmeyer@entec.Wichita.NCR.COM