sims@stsci.EDU (Jim Sims) (11/02/87)
Is there anyone working on a controller to allow the use of IBM type
disk drives on the Amiga? I've seen the drives VERY cheap -
10 mb less controller $98
20 mb w/controller $268
Granted, its not much storage and it's not as fast as SCSI, but it would
hold WB, C dev disks, some source, and a few games.
How much (and how big) are the drives for a 2000?
--
Jim Sims
Space Telescope Science Institute
Baltimore, Md. 21218
sims@stsci.edupapa@uscacsc.UUCP (Marco Papa) (11/08/87)
All IBM-type disks used in the XT/AT models are compatible with the A2000. These are ST506 drives. Only problem you need half-height drives, while most IBM clones use full-height. Prices are going down rather sharply. The best deal I have seen is for 42 Meg Miniscribe 3650 5 1/4 half-height for $349 in either PC-Week or PC-magazine. Lots of mail-orders will sell it for $399 with the IBM controller that you need only if you have the bridge card, and throw away if you have the A2090 Commodore hard disk controller. If you want just 20 Meg, bet prices are around $299, so you'll be better off with getting larger models (if you have the extra $100). -- Marco Papa Felsina Software P.S.: The Miniscribe 3650 has an access time of 61 msec with one partition, and 42 msec. if subdivided in two equal partitions.
bakken@tahoma.UUCP (11/09/87)
In article <73@mithras>, sims@stsci.EDU (Jim Sims) writes: > Is there anyone working on a controller to allow the use of IBM type > disk drives on the Amiga? I've seen the drives VERY cheap - > > [etc] > > Granted, its not much storage and it's not as fast as SCSI, but it would > hold WB, C dev disks, some source, and a few games. > How much faster is SCSI compared with ST506? And how cheap (relative term) are 40-80 MB SCSI drives getting? Thanks for any responses. -- Dave Bakken Boeing Commercial Airplane Company uw-beaver!ssc-vax!shuksan!tahoma!bakken Disclaimer: These views are my own, not my employers.
rad@masscomp.UUCP (Bob Doolittle) (11/11/87)
[ Everyone else has a line here - I may as well too ] In article <303@uscacsc.UUCP> papa@pollux.UUCP (Marco Papa) writes: >All IBM-type disks used in the XT/AT models are compatible with the A2000. >These are ST506 drives. Only problem you need half-height drives, while >most IBM clones use full-height. Actually this is only sort of true. If you have one 3.5" floppy and a 5.25" floppy, and you want to mount your new disk internally, you need a 1/2 height drive, because it needs to go where the second 3.5" floppy would otherwise go. On the other hand, if you have both 3.5" spaces used up, OR WANT TO SAVE $$ BY BUYING A FULL HEIGHT DRIVE, you can put the new disk external, which is what I'm doing. I already have a 20 Mb 1/2 height internal (and the 3.5 and 5.25 floppies), and want to add an ST506 85 Mb drive, so I am going to leave it outside the case. I have to get a couple of new cables, and I will route them out the back panel through the unused slots above the serial port. Sure, it'll look kludgy, but I'll just have to suffer for the extra disk space :-). You may have to put a fan by it, or place it near the A2000 exhaust fan, to keep it cool. Good Luck! Bob Doolittle UUCP: {ihnp4,seismo,decvax}!masscomp!rad
peter@dalcsug.UUCP (Peter Philip) (11/11/87)
Now, I do know that when you buy a hard disk, you look for a low seek and access time, but in reality, what is the difference between a drive with 65ns access time and 35ns access time? Would this make a visible difference in normal operation? How can I tell what are reasonable speeds for the various specifications given in the magazines? - Peter Philip
klm@munsell.UUCP (11/13/87)
In article <186@dalcsug.UUCP> peter@dalcsug.UUCP (Peter Philip) writes: >Now, I do know that when you buy a hard disk, you look for a low seek >and access time, but in reality, what is the difference between a >drive with 65ns access time and 35ns access time? Would this make ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >a visible difference in normal operation? How can I tell what are >reasonable speeds for the various specifications given in the magazines? Whoo! Gosh! Where do I sign up for one of these?!! :-) :-) In reality, you wouldn't notice the difference between two drives that went that fast. Access time (like 65 milliseconds (ms) and 35 ms) is the time it takes to move the head from track to track. Another spec. that is important is the transfer rate (i.e. how fast data goes to and comes from the drive.) If your file system (AmigaDOG) does a lot of thrashing, then you will probably notice a difference between a 65ms seek time and a 35ms seek time drive. The 35ms drive will be faster. In real reality, it might not make that much difference, because the Amiga can't advantage of really fast disks anyway. Most of the famous name drives you see advertised are of reasonable speed. That doesn't mean I'd want to use one on a VME bus, though. -- Kevin McBride, the guy in the brace // | Your mind is totally controlled Eikonix - A Kodak Co. // | It has been stuffed into my mold Billerica, MA \\ // Amiga | And you will do as you are told {encore,adelie}!munsell!klm \X/ Rules! | until the rights to you are sold
ewhac@well.UUCP (Leo 'Bols Ewhac' Schwab) (11/13/87)
In article <186@dalcsug.UUCP> peter@dalcsug.UUCP (Peter Philip) writes: >Now, I do know that when you buy a hard disk, you look for a low seek >and access time, but in reality, what is the difference between a >drive with 65ns access time and 35ns access time? Would this make ^^^^ ^^^^ >a visible difference in normal operation? [ ... ] I don't know about you, but if I had a hard drive with 65 nanosecond access time, I'd be flying past everyone. Where'd you get these drives? Mind you, it'd have to be very heavy, to prevent head inertia from physically throwing the drive all over the place. And the head positioner would suck tons of current when active, no doubt...... :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) _-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_ Leo L. Schwab -- The Guy in The Cape ihnp4!ptsfa -\ \_ -_ Recumbent Bikes: dual ---> !{well,unicom}!ewhac O----^o The Only Way To Fly. hplabs / (pronounced "AE-wack") "Work FOR? I don't work FOR anybody! I'm just having fun." -- The Doctor
hah@mipon3.intel.com (Hans Hansen) (11/13/87)
In article <186@dalcsug.UUCP> peter@dalcsug.UUCP (Peter Philip) writes:
$Now, I do know that when you buy a hard disk, you look for a low seek
$and access time, but in reality, what is the difference between a
$drive with 65ns access time and 35ns access time? Would this make
$a visible difference in normal operation? How can I tell what are
$reasonable speeds for the various specifications given in the magazines?
$
The 65ns drive is used to replace all RAM in your system, the 35ns drive
is used to replace all of the RAM in the 25MHz 68020 system. :-) By the
way where can I get either of these drives... boy do I have an application...
Seriously the major difference between the 65ms(milli-second) drive and
the 35 or less ms drives is the seek time overhead. For multiple disk
I/O intensive programs this amounts to much lost/wasted time.
$- Peter Philip
Hans hah@inteloa.intel.comcmcmanis%pepper@Sun.COM (Chuck McManis) (11/13/87)
In article <1367@squeaker.munsell.UUCP> (Kevin McBride) writes: >Access time (like 65 milliseconds (ms) and 35 ms) is the time it takes to >move the head from track to track. Another spec. that is important is >the transfer rate (i.e. how fast data goes to and comes from the drive.) Actually, the second most common spec quoted for hard disks (after capacity) is 'Average Access Time'. This is the average time it takes for the heads to go from where you are, to where you want to be. Seagate drives are pigs and have access times of 85 milleseconds, Maxtor drives are much quicker and have access times in the range of 18 - 28 milleseconds. This is related to the track to track time (usually in the microseconds) however voice coil drives always whip the pants of stepper motor type drives. Why do you care? Because AmigaDOS tends to fragment the drive with the directory in the middle tracks and the data in the outer tracks. The disk heads end up going from here to there quite a bit. The smaller the average access time the faster the disk files are found/read. As of this writing that can be overwhelmed by AmigaDOS overhead, however Andy F. has told us that will be changing. --Chuck McManis uucp: {anywhere}!sun!cmcmanis BIX: cmcmanis ARPAnet: cmcmanis@sun.com These opinions are my own and no one elses, but you knew that didn't you.
mph@rover.UUCP (Mark Huth) (11/16/87)
In article <33847@sun.uucp> cmcmanis@sun.UUCP (Chuck McManis) writes: >to go from where you are, to where you want to be. Seagate drives are pigs >and have access times of 85 milleseconds, Maxtor drives are much quicker Seagate 225 (st506 20MB drives) have average access time of 65 ms. Seagate 251 (st506 40MB drives) have average access time of 40 ms. These are from the spec sheets. Larger drives tend to be faster, as they are made from newer technology. Mark Huth
mph@rover.UUCP (Mark Huth) (11/17/87)
ST506 provides for hard disk data rates of 5Mb per second back to the controller, most SCSI drives run at 10Mb per second. This is the data transfer rate, and has little to do with the perceived performance when driven through the file system. A parameter which is noticed is the average access time, as this generally is related to the seek time of the drive, and the current file system does a lot of seeks. The average access time varies from model to model. Seagate 225 are 65ms, 251s are 40ms. Other vendors have done better than this in their newer hardware. Drives with average access times around 28ms are commonly available in larger capacity drives, both SCSI and ST506. Mark Huth
hue@netcom.UUCP (Jonathan Hue) (10/03/89)
I dropped by Corporate Systems Center in Sunnyvale, CA today at lunchtime and picked up their latest catalog. Here are what I consider to be the good buys: (all equipment is new, SCSI of course) CDC Wren V (94181-702) 638MB 16ms $2495 1yr warranty Maxtor 8760S 700MB 18ms $2395 1yr warranty Seagate ST138N 30MB 28ms $239 90 day warranty Seagate ST157N 44MB 28ms $329 90 day warranty CSC 730 North Pastoria Sunnyvale, CA 94086 (408) 737-7312 If nobody objects, I will post the "best buys" whenever their new catalogs come out (every 2 months or so) as a service to comp.sys.amiga readers who are looking for good prices on SCSI drives. I have no connection with the company except being a satisfied owner of a disk drive I bought there a few months ago. -Jonathan