km@cadre.dsl.PITTSBURGH.EDU (Ken Mitchum) (10/20/88)
I hope this is not a ridiculously simple question, but I am interested in finding out what the differences are between DC300 and DC600A tape cartridges (besides the length). Specifically, is there a different pattern of tape holes that can be detected to determine which cartridge is in the drive? I bought some surplus Cipher "floppy tape" drives (model 526) at a hamfest. They work fine with DC600A tapes, but stop dead after retensioning DC300 tapes. Length is not the problem, as the 150 ft version of DC600 also works. The Cipher manuals are of no help, only to say to use DC600 tapes. Since I have a large potential supply of DC300 cartridges, I would like to use them if possible. Ken Mitchum Decision Systems Labs University of Pgh
cdold@starfish.Convergent.COM (Clarence Dold) (10/22/88)
From article <1631@cadre.dsl.PITTSBURGH.EDU>, by km@cadre.dsl.PITTSBURGH.EDU (Ken Mitchum): > I hope this is not a ridiculously simple question, but I am interested > in finding out what the differences are between DC300 and DC600A tape > cartridges (besides the length). Specifically, is there a different > pattern of tape holes that can be detected to determine which cartridge > is in the drive? > Quoting from Section 3.3 of the Archive 5945L Product Description: "...DC300XL ...DC600A... Different write currents are required for the two cartridges due to the difference in oxide coating thickness and coercivity. The Model 5945L Intelligent drive determines the cartridge type by measuring the distance between the BOT and load point holes (3 feet for DC300XL and 4 feet for DC600A) and selects the appropriate write current for the cartridge which is inserted." End Quote. The interface from the Archive controller to the Drive (usually colocated) contains a 'high current' signal, put out by the controller, after the DC300 tape is detected. My limited experience shows that the DC300 will work, but not reliably. The older tapes might not be quite good enough to handle the tighter spacing of the 9 tracks found on the 60MB verses a 20MB/4track utilization on the older decks. characters per inch is still the same: 60MB / 9track / 600 feet = 11.1 kB/ft 20MB / 4track / 450 feet = 11.1 kB/ft All of the above means that it works on Archive decks, but maybe the Cipher says "if DC300, then die" -- --- Clarence A Dold - cdold@starfish.Convergent.COM (408) 435-5274 ...pyramid!ctnews!professo!dold MailStop 09-031 P.O.Box 6685, San Jose, CA 95150-6685