pz@munsell.UUCP (Paul Czarnecki) (05/12/88)
A friend of mine with no net access is looking for a Mac+ device
driver for Xebec 1410A SCSI controller driving a Seagate ST225.
If anybody has one he would appreciate it.
Please email to mail as I do not normally read this group.
pZ
--
Paul Czarnecki -- Spam, spam, spam, Usenet, and spam
{{harvard,ll-xn}!adelie,{decvax,allegra,talcott}!encore}!munsell!pzpz@munsell.UUCP (Paul Czarnecki) (05/20/88)
A little while ago I posted this: >A friend of mine with no net access is looking for a Mac+ device >driver for Xebec 1410A SCSI controller driving a Seagate ST225. What follow are the responses I've gotten. I asked Henk to send me his patches. I'm going to find the Visniac driver locally. Thanks to all who responded. pZ ---------- From: ll-xn!ames!coherent!dplatt (Dave Platt) Organization: Coherent Thought Inc., Palo Alto CA I'd suggest trying out Ephraim Vishniac's SCSI Formatter & Installer; it comes with two functional drivers (one for synchronized I/O and one for blind I/O) and is extremely flexible. It's shareware (one pint of blood, or a cash donation... to the Red Cross in either case). It's available for anonymous FTP on SUMEX, and is on a number of good Mac bulletin-board systems. If you need a copy and can't acquire one locally, drop me a line... I have it in my collection at home (haven't used it, but ya never know...) -- Dave Platt VOICE: (415) 493-8805 USNAIL: Coherent Thought Inc. 3350 West Bayshore #205 Palo Alto CA 94303 UUCP: ...!{ames,sun,uunet}!coherent!dplatt DOMAIN: dplatt@coherent.com INTERNET: coherent!dplatt@ames.arpa, ...@sun.com, ...@uunet.uu.net ---------- From: ll-xn!ames!atari!sun!portal!cup.portal.com!chrisj Message-Id: <8805121349.1.137@cup.portal.com> Paul, The S1410A is a SASI controller. SASI is an ancestor of SCSI, but neither SASI nor SCSI is a subset of the other. As an example of the problems which you run into, you must send an Initialize Drive Characteristics command (opcode hex 0C) to the S1410A, describing the geometry of the drive, etc., before you can read or write the device (or maybe just before you can read/write the higher numbered cylinders). SCSI controllers find out that information some other way, or else they don't need it, so the boot routines in the Mac ROM will not send that command before they try to read the partition table and the driver from the disk. If the ST-225 has the same number of heads as the ST-506 (namely 4), then you _may_ get away with that, since the ST-506 is the default if you don't send the 0C command. However, I'm pretty sure that in that case you cannot seek beyond cylinder 153. As long as your driver gets a chance to send the command before you need to read/write the higher part of the disk, you may be ok. Neither will the ROM fill in a field in the transmitted command block which the S1410 uses to tell it the track-to-track stepping delay. However, I _think_ that the controller will just seek the drive much more slowly than necessary, rather than not working at all, as a result of that difference between SASI and SCSI. Depending on the ROM rev. level of the controller, either the 3 or 4 most sig. bits of byte 5 of the command block are used for that. In SCSI, bits 6 and 7 are vendor- defined, but bits 4 and 5 are reserved for future use. As another example, the least sig. bit of byte 5 of a read command is defined in SCSI as the Link bit (ie., "there is another command coming after this one"), but in the S1410 as "disable the 4 retries in case of error." I don't think that your friend will be successful in using a 1410A with a Mac SCSI port, and I'm 99% certain that he can have no hope of ever booting from it. If he wants to proceed anyway, your friend should compare the Xebec S1410 Owner's Manual and a publication such as the SCSI Guidebook (published by Adaptive Data Systems, Inc.) to see what he's up against. If anyone sold your friend that controller as a SCSI device, the seller is either an ignoramus or a fraud. I hope the friend got it for free from a friend who was upgrading his IBM XT to a better disk controller, rather than actually paying money for it. The reason that you can buy them for about $40 from some surplus shops is that they are not very good controllers by modern standards. (Mine, in use on my Apple //e, was bought in 1982, when it was a pretty reasonable product, like the genuine Seagate ST-506 5-megabyte, 170-millisecond drive which it controls, but the state of the art has advanced quite a bit since then.) I suggest that your friend spring for the $100 to $150 for a real SCSI controller. (ACP controllers have a good reputation). If he didn't buy the drive yet, he might want to simplify things buy spending the extra bucks for the ST-225R (I think that's the suffix anyway), which includes a built-in SCSI controller. He's sure to find someone who has a driver for that hardware, and it makes installing the stuff in a box that much easier, as well. In fact, I'm pretty sure that the so-called non-functional sample driver which you can get in source form from APDA works ok with the ST-225R. Frankly, with commercial HDs for the Mac+ starting at about $525 (street prices), I'm not sure it makes sense to try to roll your own, unless you can scrounge most of the necessary components for free. Or unless you want to specify particular characteristics for your own needs, such as a full-height fast seeking drive, instead of the usual slow half-height one. (ST-4026 instead of ST-225, or ST-4038 instead of the RLL ST-238, or a non-Seagate brand). Christopher Jewell chrisj@cup.portal.com ucbvax!sun!cup.portal.com!chrisj ---------- From: ll-xn!ames!ncar.UCAR.EDU!oddjob!uwvax!harvard!ut-sally!uunet!mcvax!tnosel!hvt (henq) Organisation: TNO-IBBC Postbox 49 2600AA Delft, The Netherlands Organization: Organisation for Applied Scientific Research, IBBC-TNO, The Netherlands Hi, A have an old CMI 19M/15M unf./formatted drive connected to my Mac 512KE via a Xebex 1410 card. A friend of mine did and ugly patch on the Visniac formatters and drivers and it works, for over half a year already. If you want them (no sources available, all binary patches!) reply by mail. Good Luck -Henk vanTijen Have a nice day! ---------- -- Paul Czarnecki -- A Newsfeed is Sometime Thing {{harvard,ll-xn}!adelie,{decvax,allegra,talcott}!encore}!munsell!pz
michael_alan_hauser@cup.portal.com (05/30/88)
A friend of mine helped me patch the Apple SCSI driver to work with the Xebec 1410A. It works fine and several friends have been using this setup for over 18 months. One of them patched SF&I so that it mounts the drive without going through the dialog interaction. By setting this as the startup program on a floppy, the hard disk is automatically mounted at bootup (after the floppy). Due to incompatabilities between SASI and SCSI, the 1410 controller cannote be daisy chained with other Mac SCSI devices and must be the sole SCSI device on the bus. Michael Hauser Hummingbird Software Usenet: sun!cup.portal.com!hummingbird MacNET: HAUSER