herbie@bruce.cs.monash.OZ.AU (Andrew Herbert) (07/18/90)
Here is a summary of the information I received regarding AT bus scsi cards. Many thanks to the people that replied. This summary gives info on the following cards: Adaptec AHA1540B/1542B DTC 3280A Future Domain TMC830 Western Digital WD FAST-ATXT Western Digital WD 7000-FAST I have not included prices, but the above cards are priced in the approximate range of US$150 to US$550. My guess is that the WD ATXT is the cheapest, followed by DTC and Future Domain, then Adaptec and finally the WD 7000 (the most expensive). All things considered, Adaptec seems to be the way to go. However, all of the cards mentioned are most likely very good except for the WD FAST-ATXT. Cheers, Andrew --- Adaptec AHA1540B/1542B ---------------------- * Maximum SCSI->AT transfer rate: 10M bytes/s (motherboard-dependent). (Bus master DMA, => card drives bus directly, not via the PC's DMA controller.) * Synchronous transactions (i.e. scsi-2) supported. * Onboard cpu handles SCSI protocol and allows the card to be used like a standard MFM controller (presumably at the BIOS level) by mapping between physical and virtual disk geometries (e.g. sectors/track, number of cylinders). * Onboard BIOS provides OS compatibility (well, DOS at least :-); SCO Unix, Interactive Unix and Esix support the controller through standard drivers. * The 1542B is the 1540B plus floppy support. DTC 3280A --------- Little is known about this card, except that it works with DOS without any special drivers. It includes floppy support. The installation guide states: "All SCSI devices that conform to the American National Standards Institute (ANSI) X3.131-1986 and Common Command Set (CCS) Rev. 4b specs are supported by the DTC31/3280A". Maximum throughput is >= 800k bytes/s (obtained using Seagate ST4376N with a 20MHz 386). "The only problem I have had is that the floppy disk drives only seem to recognise the first media density type you use after bootup i.e. if you put a high density disk in the drive, it will then not work with low density disks (they both used to work as the floppy drives are dual density). I'll probably have to go back to the dealer on that one. Apart from that I'm quite happy." Future Domain TMC830 -------------------- ISC (e.g. Interactive Unix) supports this controller. Western Digital WD FAST-ATXT ---------------------------- "The WD FAST-ATXT controller is a dog." * No intelligence, device driver required for DOS. Western Digital WD 7000-FAST ---------------------------- From comments on the net, this card is roughly equivalent in performance to the AHA1540B. There is doubt as to whether the driver for Interactive Unix 2.2 actually works.
feustel@well.sf.ca.us (David Alan Feustel) (07/21/90)
What is(are) the difference(s) between the 1542a and the 1542b?
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USMAIL: Dave Feustel, 1930 Curdes Ave, Fort Wayne, IN 46805-2710pauls@inco.UUCP (Paul Stygar) (07/26/90)
In article <2683@bruce.cs.monash.OZ.AU> herbie@bruce.cs.monash.OZ.AU (Andrew Herbert) writes: >Here is a summary of the information I received regarding AT bus scsi cards. >Many thanks to the people that replied. ... >I have not included prices Best price I've seen on the 1542B is at Treasure Chest (see ad in Computer Shopper for phone #) ... about $230 >Adaptec AHA1540B/1542B >---------------------- >* Maximum SCSI->AT transfer rate: 10M bytes/s (motherboard-dependent). > (Bus master DMA, => card drives bus directly, not via the PC's DMA > controller.) Where did this info come from ???? I didn't see any info in the User Manual for the 1542B to directly confirm this ... The board can be jumpered to set the DMA Transfer Speed to 5.0, 5.7, 6.7, or 8.0 MB/s (via PINS 12,13 of the J5 Jumper Block) (p. 2-9 of AHA-1540B/1542B User's Manual, Rev 1.0, April 1990). Not to mention, I don't understand this info, since the 1542B seems to run OK on an ancient (circa 1988) MICRONICS 20 Mhz motherboard which only supports 4 Mhz DMA transfer rate. -- -- | UUCP: {alembic, grebyn}!inco.UUCP!pauls (Paul Stygar) | | MDESC, 8201 Greensboro Drive, McLean, VA 22102 (703) 883-3998 | | BEGIN_DISCLAIMER;_____The_views_expressed_by_me_in_no_way_reflect_the | | views_of_McDonnell_Douglas_or_its_subsidiaries._______END_DISCLAIMER; |
jmerrill@jarthur.Claremont.EDU (Confusion Reigns) (08/02/90)
In article <19159@well.sf.ca.us> feustel@well.sf.ca.us (David Alan Feustel) writes: > >What is(are) the difference(s) between the 1542a and the 1542b? The 1542a is a full-length card; the 1542b uses more integrated electronics to put the same functionality on a shorter card. That's how I understand it, anyway. -- Jason Merrill jmerrill@jarthur.claremont.edu DISCLAIMER: I don't work for Adaptec.