bobl@pro-graphics.UUCP (Bob Lindabury) (07/11/89)
Network Comment: to #405 by pnet01!crash!DOCKMASTER.NCSC.MIL!AELevy Allan wanted the SCSI jumper setting so that CMS drives (an homebrew drives) would work with the Apple SCSI card. The jumper is on the back of the CMS drive and is actually a dip switch. Switch dip 8 to it's non-standard position. I'm not sure if that is closed or open at this point. If you don't have a CMS, you will have to either jumper or unjumper the corresponding jumper on the SCSI drive. I will see if I can get any clearer instructions as I don't use the Apple SCSI myself. At any rate, here is some more miscellany about SCSI cards and drives... SCSI NOTEBOOK Dr. Ken's Notebook of SCSI Miscellany If you are using the Apple SCSI Interface Card you MUST turn your hard drive ON & wait for it to come up to speed and position the heads off their landing (parking) zone BEFORE you turn your computer ON. Using one of the Seagate STxxxN series of drives, this time is generally about 30 seconds. (In contrast, if you are using the CMS SCSI Interface Card, you can turn ON the hard drive and computer simultaneously.) If you fail to do this, the SCSI hard drive will NOT be visible to your computer. This is a major drawback to BBS SYSOPs who wish to have their systems autoboot on power in the event a power failure occurs. If you wish to use the Apple SCSI Interface Card on a CMS drive, you MUST flip dip switch #8 on the back panel to its non-default position before the system will recognize the device. CMS and MacCrate cases have dual DB-25 pin connectors on the back plates, thus the cable you need is a DB-25 to DB-25. The AppleHive (AHive) case from Tulin has dual Centronics-like 50-pin SCSI connectors and thus the cable you need is a DB-25 to Centronics 50-pin (same as used on the Apple hard drives). To prepare a hard drive for use with the Apple SCSI card: 1 - Perform the low-level formatting using SCSI HACKER by Joe Jaworski or HDFORMAT by Tim Grams. 2 - Use the HDSCPARTITION supplied on the Apple SCSI Interface Card utilities disk to create the partitions. HDSCPARTITION was written for a max drive size of 40 megs (Apple's own drive) so you will be setting the partition info on the drive to 2 20 meg partitions. 3 - Use ADU (Advanced Disk Utilities) under GS/OS to alter the size of the 2 20 meg partitions created by HDSCPARTITION to whatever is appropriate for your drive. If you use a Seagate ST277N 65 meg (unformatted size) drive, you can have 2 31 meg partitions. 4 - Use any ProDOS disk formatter to ProDOS-format the partitions. Using the CMS SCSI Interface Card with a Seagate ST277N drive (including CMS' own SD60 A2S drive) you can partition the first volume to 30 megs and the second volume to 32 megs for a total of 62 useable megs - same as if you use the Apple SCSI Interface Card (which allows 2 31 meg volumes). Seagate STxxxN SCSI drives use approximately 12.5 watts power. The fans in most cases use next to nothing in terms of wattage. Thus a 30 watt power supply or more is more than sufficient to power 1 or 2 Seagate drives. The most inexpensive enclosure you can purchase is a dual half-height floppy drive case with power supply, starting at $50. Although not very attractive, you can find these cases which are durable. For example, Computer Shopper contains several vendors selling such cases starting at $55, and a visit to any local Ken Gordon computer faire & flea market can usually turn one or two up. Another alternative is to use a computer case from a small footprint system, such as a Sanyo case - more attractive and allows for greater drive expansion (usually 2-4 drives) but it has a slightly larger footprint. Then again, such a case can usually be placed beneath an Apple //gs & help raise the monitor up closer to eye level (better on the back and neck, as well as the eyes). Apple // SCSI chains allow up to 8 SCSI devices per chain, BUT the SCSI Interface Card counts as one SCSI device. Thus, you can effectively chain up to 7 devices off the SCSI Interface Card. If you are using an Apple //gs and GS/OS, make sure you have the SCSI.DRIVER in the /SYSTEM/DRIVERS folder. Seagate STxxxN SCSI drives have auto-parking heads - turn the power OFF and the heads are moved onto a landing zone. When you turn the hard drive ON, you will hear noises indicating that the heads are being moved onto the active disk surfaces from their parking zones. This is normal, so do not panic... panic if you DON'T hear these noises! What size drive to buy? First, what can you afford? Second, how much storage do you currently need? This is comparatively easy to determine simply by looking at what you currently have & use. (Remember, copy protected games USUALLY won't allow you to move them entirely over to a hard drive. See, I told you NOT to buy copy-protected software, but did you listen? Nooooo!) Usually this will give you a fairly good idea as to what your present needs are. But what about future storage needs? This one is tough. If you look at the Mac & MS-DOS worlds, you can get a fairly good idea as to the future of software: the move is toward much larger & more integrated packages requiring much more disk storage simply for the program software, let alone data. You can see this trend in the //gs world - look at AppleWorksGS & GS/OS and you see what I mean. There are two simple options for immediate expansion capabilities: Buy a larger hard drive than you currently need, or at least purchase a case & power supply which will allow you to add additional drives as needed. The second option is one I prefer since hard drive prices continue to drop, but the first option makes sense if you don't go over-board with it - the price per meg is lower for a 60 meg drive than it is for a 20 or 40 meg drive (all else equal, such as brand, speed, etc.). The last time I ran the calculations, two 60 meg drives were cheaper than a single 120 meg drive, so the price per meg curve is indeed bell-shaped. Bottom line - its up to YOU, but shop around since prices not only change temporarily but also vary among vendors. _______________________________________________________________________________ UUCP: crash!pro-graphics!bobl | ProLine: bobl@pro-graphics InterNet: crash!bobl@pro-graphics.cts.com | CServe: 70347,2344 ARPA/DDN: crash!pro-graphics!bobl@nosc.mil | AppleLink: Graphics3D _______________________________________________________________________________