re ide vs scsi david c cat uucp dave write are we talking about a scsi device e g hd on a scsi controller or are we talking about a scsi controller that had a chip upgrade using the same chip that is on a scsi controller board we are talking about a scsi device e g hd on a scsi controller here is a rewrite of my mac info sheet scsi section scsi only external device expansion interface common to both mac and ibm allows the use of any device hard drive printer scanner nubus card expansion mac plus only some monitors and cd rom normal asynchronous scsi is mhz fast synchronous scsi is mhz difference between these modes is mainly in the software drivers main problem there are a lot of external devices which are internal terminated which causes problems for more then two devises off the scsi port a scsi chain is supposed to be terminated only at the begining and end any other set up causes problems for either mac or ibm scsi bit devices per scsi controller asynchronous mb s ave and synchronous mb s max transfers bit scsi is often mistaken for a fast version of scsi see scsi for details scsi fully scsi compliant scsi mode devices per scsi controller bit scsi is implimented as a very fast scsi since it can run using scsi hardware and software drivers which limits it to devices which results in it sometimes being mistakenly consitered part of scsi bit and bit scsi require different ports electronics and scsi software drivers from scsi which makes them more expensive than other scsi interfaces bit scsi seems to run only in synchronous mode hence term wide and fast scsi transfer speeds are mb s with mb s burst bit mb s with mb s burst bit and mb s with mb s burst bit bit scsi is the biggest headache due to the fact that it is the only scsi that i know of that can pump scsi speeds through scsi devices and software controlers its main implimentation is on the mac though you do see adds for scsi at mb s maximum throughput for pcs since bit scsi does not need all the hardware including electonics and software of bit and bit scsi it is the cheepest of the scsi interfaces just pop out the scsi electornics and pop in bit scsi electronics some people consider bit where scsi really starts i used to be one of them but mb s average though put with a theoretical burst of mb s is not scsi but is bit scsi rule of thumb if it is scsin and over mb s then it is some type of scsi bit scsi can use part of scsi electronics which further reduces its cost compared to and bit scsi
