Path: utzoo!mnetor!uunet!mcvax!unido!tub!cabo From: cabo@tub.UUCP (Carsten Bormann) Newsgroups: comp.periphs Subject: Re: DAT-based cartridge tapes (1.2GB!) - any thoughts? Message-ID: <439@tub.UUCP> Date: 29 Mar 88 17:18:52 GMT References: <1833@kontron.UUCP> Reply-To: cabo@tub.UUCP (Carsten Bormann) Organization: Technical University of Berlin, Germany Lines: 108 Summary: Look at the market. In article <1833@kontron.UUCP> brad@kontron.UUCP (Brad Yearwood) writes: () [...] If this tape holds anything, it holds 1.2GB. () It's from Gigatape, located near Munich. They want about $7K () equivalent for the drive, depending on interface. A cartridge () is about $28. (That's an awfully spindly looking little scrap () of tape to be holding 1.2GB!) () () Speed claims are 192KBytes/second [...] () Such a device is very tempting for overnight backup use. [...] Gigabyte tape drives are certainly the wave of the future. Due to the large numbers of systems out there that have Gigabyte disk drives and no comparable backup devices, there is a huge market. Currently there seem to be three contenders in this market: 1) Exabyte (with a product based on 8mm cartridges holding 2.2 GB); 2) Gigatape (R/DAT cartridges, 1.2 GB) 3) several companies in an ANSI committee talking about R/DAT. I'm ignoring VHS cassettes here; these tapes with their exposed oxide coatings do not really qualify for data storage (opposing opinions are welcome). All three systems are based on cartridges that are available in consumer-grade versions, manufacturers usually want to sell their ``certified'' versions of the tape. The 8mm cartridge (better known as Video 8) has been on the market since (I think) 1983. The mechanisms used in camera recorders are used for analog recording; therefore considerable modification by Exabyte was necessary to make 8mm a digital medium. R/DAT will be on the market this year (or next year, maybe) and has been designed for digital recording from the outset. Unfortunately, no standard has been reached yet that describes how to record computer data on them. Gigatape is rolling their own ``standard'' here (just like Exabyte is doing in the 8mm range). However, Gigatape will have to fight with the ANSI people currently discussing R/DAT as soon as agreements have been reached. Since the ANSI standard is not yet available, the only things we can compare right now are the two products (which are/will be sold at comparable prices). My personal assessment of just Exabyte and Gigatape: 1) Data reliability Exabyte uses read after write and re-records bad data in considerable distance to the original recording position. They use lots of redundancy in their error correction codes (one third is redundancy, if I recall correctly). The 8mm tape has not been pushed to its limits yet, Exabyte may have higher-density products in the future. Gigatape also uses error correction, but their published materials do not talk about read after write at all. If they are using consumer grade R/DAT drives, r-a-w would not seem to be possible. I have no idea about how far you can go with R/DAT cartridges with respect to recording density and if 1.2 GB is pushing anything. 2) Cartridge availability You can buy 8mm cartridges of good quality in any supermarket. R/DAT cartridges will only become available in quantity when the audio R/DAT market has resolved the copy protection issues (which is scheduled to happen this year, but may never happen at all). 3) Systems integration Exabyte's drive has the 5 1/4" form factor, which is an important issue when it comes to integration into existing systems. It runs from standard +5/+12 volt power supplies. Exabyte has a working SCSI interface with 1/4 MB buffer storage. I have seen it streaming at more than 200 KByte/s. The interface boards are built in high quality, using surface mount technology for many components. Gigatape's drive looks like a stereo cassette deck, no integration into existing boxes is possible (but they are promising a 5 1/4" version by the end of this year). Gigatape is promising to have ESDI, SCSI and Pertec (half inch tape drive) interfaces. Looking at the interface boards they displayed in Hannover did not thrill me too much (they didn't even have the solder stopping silk screen on them yet). 4) Market positioning Exabyte tries to deliver a high-end product for the PC network, workstation, and minicomputer market. They are a 50+ person company with considerable funding, located in the US of A. They have a second source in Japan. Exabyte's product is available and has proven to work in varying operating conditions. Gigatape is a small German startup company (not that I dislike Germany, but I don't know of many successful peripheral products that originated from here). In Hannover, Gigatape promised to deliver in April (I hear that they repeatedly promised to deliver next month). Disclaimer: I sometimes do some consulting for a systems integrator in Germany, and I recommended Exabyte to them when they asked me. -- Carsten Bormann, Communications and Operating Systems Research Group Technical University of Berlin (West, of course...) Path: ...!pyramid!tub!cabo from the world, ...!unido!tub!cabo from Europe only.