kr@jet.uucp (ken reed) (04/25/91)
We currently have a specialised piece of hardware (a CAMAC Serial Highway Driver) plugged into one of our Sun's VME slots. Now it looks like we may want to connect this device to machines (30 or so of them) that do not have VME slots (for reasons of cost). We don't want to re-design the VME card so the simplest and cheapest solution seems to be to use a SCSI-to-VME converter and connect the SHD in via a SCSI controller. We plan to dedicate a controller for this interface so that we run no risk of disturbing the disks connected to the other. I've written the UNIX device driver for the current VME set-up and am starting to read-up on SCSI to do the new driver. However, at the moment I know next to nothing about it and I thought it might be wise to ask if we're trying to do something silly before expending too much effort on this project. I have two specific question areas (hence this posting to 2 groups) that I would be *most* grateful for any comments on. 1: (for comp.unix.internals) Is there any reason why there shouldn't be a separate SCSI kernel driver operating independently of any existing one driving discs, etc? I can't see any reason why not but, only having written one driver so far, my knowledge is limited. 2: (for comp.periphs.scsi) Are we being silly in trying to use SCSI in this way? What is needed is the ability to transfer data (with firmware help in the SHD) between the UNIX box and the VME SHD card and receive an interrupt from the SHD. From what I've read so far it seems reasonable but I've only ever seen disks and tapes plugged in via SCSI. The real pain is that we don't know (yet) what type the target machines will be, so bus adaptors (eg VME-SBus) are not a current option. As I said, any comments at all would be most appreciated. By the way, this is my first ever posting so, if I've messed up and this turns up in inappropriate groups, please forgive me. Many Thanks Ken Reed JET Joint Undertaking | kr%jet.uucp@ukc.ac.uk (world) Abingdon, Oxon, OX14 3EA, UK | kr@jet.uucp (UK only) -- Ken Reed | tel: +44 235 528822 ext 4995 JET Joint Undertaking, | kr%jet.uucp@ukc.ac.uk (world) Abingdon, Oxon, OX14 3EA, UK | kr@jet.uucp (UK only) - Disclaimer: Please note that the above is a personal view and should not be construed as an official comment from the JET project.