[HECnet] VAX-11/725 with RC25 (was: Re: Reading RT11 files under Windows or Linux)

[Johnny Billquist]

On 2021-04-21 22:34, Paul Koning wrote:
> 
> 
>> On Apr 21, 2021, at 4:25 PM, Dave McGuire <mcguire at neurotica.com> wrote:
>>
>> On 4/21/21 4:05 PM, Mark J. Blair wrote:
>>>>>> Anyone have an RC25 unit?  I have a few of them in need of imaging up before they are lost forever...
>>>>>
>>>>> I do not have one yet, but I would be interested in buying a VAX-11/725 if one came along at the right price and location. I'm in Riverside, California, USA. I keep hearing so much ire directed towards the RC25, that I have a sick fascination with experiencing one for myself, and seeing just how much slower it feels vs. my 11/730.
>>>>
>>>> The VAX itself won't feel any slower; it's the same board set as the
>>>> 11/730.
>>>
>>> For CPU-heavy stuff, but isn't the RC25 subsystem a lot slower than the RL02+R80 subsystem? See, I need a VAX-11/725 so I can be an expert on this stuff! :)
>>
>>   Excellent acquisition rationalization. ;)  But yeah, the RC25 is
>> noticeably slower than the (already pretty slow) IDC controller that
>> handles the R80 and RL02 in an 11/730.  (I had an 11/725+RC25 many years
>> ago, and a standard-config 11/730)  I was just thinking CPU differences,
>> of which there are none.  Context fail. ;)
>>
>>             -Dave
> 
> Is that specific to the RC25 controller used on that machine?  On PDP11s, RC25 is an MSCP device, and I don't remember ever hearing it was particularly slow.  Of course, it was a pain in the neck with its fixed drive section, but that's a different issue.

My recollection is that the drive itself is horribly slow. But I 
wouldn't be surprised to learn that the controller is abysmal as well.

MSCP don't say anything about the speed of the thing.

The RQDX1 is also MSCP. But that thing is slower than molass. And you 
can't blame it all on the drives...

   Johnny

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol