lphillips@lpami.wimsey.bc.ca (Larry Phillips) (09/08/89)
In <19653@gryphon.COM>, jburnes@pnet02.gryphon.com (Jim Burnes) writes: >Does anyone know how many times slower Microbotics SCSI adapter is than >a true DMA adapter? Microbotics claims it is "psuedo-dma", but in my book tere >is only DMA and non-DMA. Also does anyone know of any adverse effects that >said controller has on your basic Amy 1000? Also how good is the software >that Microbotics supplies. Any help would be greatly appreciated. >Thanks in advance. Are you speaking of the Microbotics HardFrame? If so, it is DMA. You may be thinking of one of the GVP products, in which case it is what they call 'psuedo-DMA'. It really means that they DMA to/from a small chuck of memory on the host adapter that is not connected to the Amiga bus during the transfer. The processor then gets access to this buffer and does the transfer in one swell foop, er... fell swoop, er... swell loop. Whatever. -larry -- The Mac? Oh, that's just like a computer, only slower. +-----------------------------------------------------------------------+ | // Larry Phillips | | \X/ lphillips@lpami.wimsey.bc.ca -or- uunet!van-bc!lpami!lphillips | | COMPUSERVE: 76703,4322 -or- 76703.4322@compuserve.com | +-----------------------------------------------------------------------+
jburnes@pnet02.gryphon.com (Jim Burnes) (09/09/89)
Hi!
Does anyone know how many times slower Microbotics SCSI adapter is than
a true DMA adapter? Microbotics claims it is "psuedo-dma", but in my book tere
is only DMA and non-DMA. Also does anyone know of any adverse effects that
said controller has on your basic Amy 1000? Also how good is the software
that Microbotics supplies. Any help would be greatly appreciated.
Thanks in advance.
Jim Burnes
UUCP: {ames!elroy, <routing site>}!gryphon!pnet02!jburnes
INET: jburnes@pnet02.gryphon.comblgardne@esunix.UUCP (Blaine Gardner) (09/11/89)
From article <754@lpami.wimsey.bc.ca>, by lphillips@lpami.wimsey.bc.ca (Larry Phillips): > In <19653@gryphon.COM>, jburnes@pnet02.gryphon.com (Jim Burnes) writes: >>Does anyone know how many times slower Microbotics SCSI adapter is than >>a true DMA adapter? Microbotics claims it is "psuedo-dma", but in my book tere > > Are you speaking of the Microbotics HardFrame? If so, it is DMA. You may be I think he was talking about the Stardrive module for the Starboard. If that's it, forget about the psuedo-DMA drivel, it's even "less" DMA than the GVP or CLtd (Kronos) "psuedo-DMA" controllers. In fact the Stardrive has the distinction of being the slowest SCSI controller available for the Amiga. Of course it's also the cheapest, so it might be worth it. -- Blaine Gardner @ Evans & Sutherland 580 Arapeen Drive, SLC, Utah 84108 Here: utah-cs!esunix!blgardne {ucbvax,allegra,decvax}!decwrl!esunix!blgardne There: uunet!iconsys!caeco!i-core!worsel!blaine (My Amiga running uucp) "Nobody will ever need more than 64K." "Nobody needs multitasking on a PC."
scott@ssgp32.UU.NET (Scott Evernden) (09/15/89)
In article <1515@esunix.UUCP>, blgardne@esunix.UUCP (Blaine Gardner) writes: > > In fact the Stardrive has the distinction of being the slowest SCSI > controller available for the Amiga. Of course it's also the cheapest, so > it might be worth it. The StarDrive must also be the hardest controller to configure, since I keep seeing messages like this that claim there is no speed possibilities with a StarDrive. I regularly achieve large block read speeds of 240-270K/sec and write speeds of almost 200K with my StarDrive. On an empy partition, I was able to attain a 291K diskperf. I think these numbers compare quite well with many other non-DMA controllers. I have't done anything special. I use a 3:1 interleave and something like 17 buffers under FFS on a ST277N. My A1000 has a 68010 which might improve performance in some cases. I did a lot of experimenting when I first got the StarDrive (different interleaves/buffers) and was able to see a broad range of performance results, so I wouldn't give up on this controller too quickly. -scott -- Scott Evernden PRIME Computer Inc. scott@ssgp32.Prime.COM Commercial Systems Group uunet!ssgp32!scott Technology Drive (508) 478-8600 x2984 Milford, MA 01757
erbvax@mars.lerc.nasa.gov (Glenn Christman (Sverdrup)) (05/02/90)
Hello all. I am looking to put a hard disk on my A-1000. I have decided to go the SCSI route, and was wondering if anyone has any experience using the Microbotics SCSI adapter that fits in thier StarBoard RAM expansion unit. This would seem to be my best alternative, since I already have that module with one board populated with 1MB. Any information or comment would be greatly appreciated. Thank you very much! - Glenn +----------------------------------------------------+---------------------+ | "Excuse me a minuet while I whip this out." | - Amiga | | - Sherrif Bart of Rock Ridge | - SparcStations | | | - VAX | +----------------------------------------------------+---------------------+ | Any opinions expressed or implied are my own, and do not necessarily | | reflect those of my employer....no matter how spacy they are. | | '73 WD8OMW | | Glenn J. Christman, NASA Lewis Research Center | +--------------------------------------------------------------------------+