Path: csiph.com!x330-a1.tempe.blueboxinc.net!newsfeed.hal-mli.net!feeder1.hal-mli.net!news.glorb.com!dotsrc.org!filter.dotsrc.org!news.dotsrc.org!not-for-mail
From: koehler@eisner.nospam.encompasserve.org (Bob Koehler)
Newsgroups: comp.sys.dec,comp.os.vms
Subject: Re: RB730 Integrated Disk Controller (R80/RL02) usable with VAX-11/750?
Message-ID: <mc8fPCpaWldp@eisner.encompasserve.org>
Date: 4 May 2011 12:22:06 -0500
References: <5a076b79-20b8-461d-93ee-e7ee8b50e249@dn9g2000vbb.googlegroups.com> <2ecc8832-029c-41a9-9f97-e4da0238ca4d@l14g2000pro.googlegroups.com> <ipo238$id3$1@Iltempo.Update.UU.SE> <UwjX65DfHFLe@eisner.encompasserve.org> <slrnis00n9.m6.rivie@stench.no.domain> <fY2UNLTT7uee@eisner.encompasserve.org> <ipqpfi$qvl$1@Iltempo.Update.UU.SE> <9hXyOq0vMb34@eisner.encompasserve.org> <ips1gq$7i2$1@Iltempo.Update.UU.SE>
Organization: Encompasserve
Lines: 17
NNTP-Posting-Host: 67.53.90.116
X-Trace: news.sunsite.dk DXC=4@lm7jG_o7enC^B`UVjTRcYSB=nbEKnkkm<f43^cX74iT1og<J9`okb\J]h`co[Tek?b]2B[Je5dcP_U0^8jMJZa[PS>Ijhe2o`4ULcHhZWA5g
X-Complaints-To: staff@sunsite.dk
Xref: x330-a1.tempe.blueboxinc.net comp.sys.dec:393 comp.os.vms:2677

In article <ips1gq$7i2$1@Iltempo.Update.UU.SE>, Johnny Billquist <bqt@softjar.se> writes:
> On 2011-05-04 06:32, Bob Koehler wrote:
>> In article<ipqpfi$qvl$1@Iltempo.Update.UU.SE>, Johnny Billquist<bqt@softjar.se>  writes:
>>>
>>> Except then of course it isn't the system bus, but just an I/O bus... :-)
>>
>>     If everything except the CPU-memory connection is on the same
>>     bus, and CPU and memory are also on that bus, then which is the
>>     system bus?
> 
> Uh? The memory is not on that bus, or even near it. I thought we had 
> just established that.

   If the memory was not on the UNIBUS, then I/O peripherals could not
   do DMA.  There might have been some PDP somewhere that I haven't
   looked at that couldn't do DMA, but all VAXen certainly can.