tom@iconsys.UUCP (Tom Kimpton) (06/20/88)
I have an opportunity to buy a Toshiba MK50FB ST-506 80 Meg drive
for $400. Considering getting a case, power supply, controller,
driver, and what-not, is this a good deal? And if it is, where
could I get the things I need to get this up and running
with the least amount of hassle? I am a software person, not
really into hardware, so while I would be willing to do some
programming if I could get some kind of sources for a driver,
I would much rather the hardware came out of a box, ready-made.
So... if anyone would know of anything to help make this a good
deal, I would appreciate their help.
Thanks!
--
Tom Kimpton UUCP: {ihnp4,uunet,caeco,nrc-ut}!iconsys!ron
Software Development Engineer ARPANET: icon%byuadam.bitnet@cunyvm.cuny.edu
Icon International, Inc. BITNET: icon%byuadam.bitnet (multi-user acct)
Orem, Utah 84058 PHONE: (801) 225-6888lazarus@athena.mit.edu (Michael Friedman) (06/26/88)
In article <246@iconsys.UUCP> tom@iconsys.UUCP (Tom Kimpton) writes: >I have an opportunity to buy a Toshiba MK50FB ST-506 80 Meg drive >for $400. Considering getting a case, power supply, controller, >driver, and what-not, is this a good deal? And if it is, where >could I get the things I need to get this up and running >with the least amount of hassle? I am a software person, not >really into hardware, so while I would be willing to do some >programming if I could get some kind of sources for a driver, >I would much rather the hardware came out of a box, ready-made. I don't know too much about the hardware side, but the driver will be a nightmare if you have to write your own. Unless you have access to a good oscilloscope, time to burn, and awesome programming skills I suggest that you spend the money for a package deal. The problem you face is that generic SCSI drivers don't exist. You can try ones that go with other drives, but there is no guarantee. As they are intended for use with only one drive they quite possibly have its size built in. That, however, is a minor problem - find it and change it. The real problem is the many differences between the timing characteristics of different drives. Any driver you find will be chock full of little routines whose only purpose is to make the Mac twiddle its thumbs while the drive does something like switch tracks. As your Toshiba is a different drive these routines will be in the wrong places. Therefore, the Mac will sometimes put out data faster than the Toshiba can accept it. (This assumes blind reads and writes. Most drivers do this.) The Mac II is a little different. There is some handshaking going on in the hardware during blind reads and writes. That will probably make things easier for you if you use a Mac II. I happen to know that some drivers that people have written (I think the one in the SCSI Developement package) work on some drives but not others. The problem, of course, is that you won't know that you have to write your own driver until you try every other driver you can get your hands on. If you do write a driver, I strongly suggest that you obtain the SCSI Developement package from APDA. I also recommend SCSI Tool. SCSI Tool is already a fantastic program. The new release is coming out too. (I'm getting a beta test version and boy do I need it!!!). Mac Tutor had a series of articles by someone who did exactly what you are doing. (A different drive, however.) There is also a Tech Note on the subject. In it they say that they will provide minor assistance, but that writing your own driver is not for the faint-hearted. -------- PS. Just be happy you don't have my job - I have to write a routine to acquire data off a board at a CONSTANT RATE and send it to any hard drive. As the SCSI Manager takes a long time when you use a loop, and as drives have unpredictable pauses during which they don't accept data, I am reduced to righting my own program that will include a circular FIFO buffer and direct access to the SCSI chip. When the disk isn't ready for info I keep grabbing data and put it in the buffer. When it is ready I catch up by sending out two values for every one I acquire. As the chip on the MAC II is undocumented I am currently engaged in dissassembling the SCSI Manager and walking through it while keeping track of bus signals with a logic probe. FUN!!! As long as the American Dream is for Americans only |||Mike Friedman it will remain our dream but not our destiny. |||quoting somebody.
psych@watdcsu.waterloo.edu (R.Crispin - Psychology) (06/28/88)
I have 2 points to make on this topic. 1) Western Digital also makes a 506 to SCSI controller. The one we used was WD1003A-SCS. I don't know if they make more. It has poor documentation which caused us many hours of work trying to figure things out. You can optionally purchase several books to go with the controller. You may want to do this. 2) Ephraim Vishniac has written a standard SCSI driver which he has made available. It is available by FTP from the INFO-MAC archives at sumex-aim and by using the TELL command through bitnet from MACSERVE@PUCC. You need to get the file UTILITY-SCSI-FORMATTER-INSTALLER.HQX.2. If you have problems Ephraim can be contacted and is very helpful. Sorry, I don't have his current email address. Richard Crispin Dept. of Psychology Bitnet: psych@watdcs University of Waterloo Unix : psych@watdcsu.UWaterloo.ca Waterloo, Ont. Canada N2L 3G1 (519)885-1211 ext 2879