CompuServe Thread

#NEC 84 and Adaptec 1742

8 messages in this thread
#36474From: Daniel BayerdorfferJan 10, 1993 10:31 AM
Clarke, I have used the /D switch with ASPIEDOS.SYS, and it does'nt list the CD-ROM. I have set the SCSI ID to ID 2. You said to check the termination and the cabling. The cabling is seated properly, but I don't know how to change the termination on the NEC 84 or on my Hard drive wich is a Western Digital Pirahna 4200. I don't even know how to check the termination on either of these for that matter. Thanks for any help you can give me. Daniel
#36534From: Clarke FerberJan 10, 1993 10:17 PM
If ASPIEDOS.SYS does not list the drive with the /D switch then it's not seeing the unit at all. In a SCSI bus the devices at each end of the cable _must_ be terminated, while all devices in between the ends of the cables must be free of termination resistors. For example: [HARDRIVE]—————[1742] Terminated Terminated [HARDDRIVE]———[CDROM]——–[1742] Terminated no-term Terminated or [CDROM]———–[HARDRIVE]——-[1742} Terminated no-term terminated or [HARDDRIVE]——-[1742]———–[CDROM] Terminated no-termination terminated Tell me a little about your system, and i'll try and figure out whats going on. If the NEC is an external unit, then you will need to pull the resistors off of the 1742 card (just below the ribbon cable). If your running the CD-ROM between the hard drive and controller in an internal configuration then you should already be working (I dont the NEC comes with internal termination). If you have added the CD-ROM to the end of the same cable as the hard drive is on then you will need to remove the termination of the hard drive (resistor packs underneath by the ribbon cable), and add termination to the CD-ROM. I'm not famililar with the NEC units, but I think they should come with a termination adapter that you plug into the drive and then plug the cable into the adaptor. Hope this helps, but give me some more info on your configuration if it does not. -C
#36569From: Daniel BayerdorfferJan 11, 1993 9:04 AM
Clarke, All my stuff is internal. I have the Adaptec terminated. I don't know if the NEC is terminated. I have put the NEC before the hard drive and after it. Neither position has made a differance. Are you sure there are terminating resistors underneath the cable on the hard drive? Thanks for any help. Daniel
#36634From: Clarke FerberJan 11, 1993 8:33 PM
Yes there _will_ be terminators on the drive itself. You may just have a dead drive. Do you know anyone else with a SCSI controller? Do the access lights on the drive ever come on during boot? How is are your 1742 options configured? Is all the Enhanced options left at normal? Especially the one for ID 2? (might want to double check your jumpers/switchs on the drive). It sounds like you may just have a dead unit. -C
#36654From: Daniel BayerdorfferJan 11, 1993 10:28 PM
Clarke, I have the enhanced options set up for their normal setup. The hard drive and the CD-ROM both light up on start up. Someone else suggested that I needed NEC to send me a new BIOS. I think this is the solution, because like you said it seems to act like a dead unit to the 1742. Thanks for the help. Daniel
#36760From: Clarke FerberJan 12, 1993 8:49 PM
Your welcome, but I would be very surprised if it needed a bios upgrade. Please let me know what you find out. -C
#36781From: Daniel BayerdorfferJan 12, 1993 11:49 PM
Clarke, I tried changing the 1742 out of synchronous mode for the NEC, and now it is working great. Thanks. Daniel
#36862From: Clarke FerberJan 13, 1993 9:33 PM
Daniel, I should have thought to tell you to try that. The NEC unit is SCSI-1 and does not support sync transfer. Other people have had the exact same problem. I'm glad to hear you got it working though. -C