Hello all, I've got an interface to an RRD40 in my VAX called a KRQ50 and
it has two "ports". One connects to the RRD40 with a 15 pin or so cable,
the other, I don't know. Then in the box of stuff that went with this is a
terminator (green LED on the back) with the same D-shell connector as the
RRD40. So I'm trying to figure out whether or not they went together. I've
never seen such a terminator before.
--Chuck
>> > I'm contemplating attempting to do this myself,
>> > but in case it's been done already, I'd just as
>> > soon as not re-invent the wheel.
>>
>> It's doable. You need to create a bootable XXDP disk and copy the
>> required formatter to it. not much more than that required.
>I figured as much; I was just probing to see if anyone had already
>done it.
Sure. Do you just want the RQDX3 utilities on it?
Up until a year or two ago, DEC would sell you a subset of XXDP on RX50's
that included the things commonly used on Micro-PDP's. They don't have
any RX50's left in inventory, though.
>BTW-- Are RL02's a maintainance nightmare? Do the advantages
>of these drives outweigh the problems (not to mention their *size*,
>or are they simply not worth it?
RL02's are, IMHO, the most reliable of all the 14" removable cartridge
drives. The embedded servo design means that absolute positioning
alignment does't have to be done. (Though the relative alignment of the
two heads does matter somewhat.) The head flies pretty high over the platter,
so crashes are rare. I know one site that ran a bunch of RL01's (mechanically
very similar) continuously for twenty years before upgrading to RL02's, and
the only problems they had were the spindle bearings wearing out.
And they aren't very big or heavy either. They're less than 70 lbs
each, so they're easy to move around. The big Massbus drives, those
are a different story.
--
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology WWW: http://www.trailing-edge.com/
7328 Bradley Blvd Voice: 301-767-5917
Bethesda, MD, USA 20817 Fax: 301-767-5927
Guys:
Has anybody ever ripped the Low Level formatter
>from the XXDP+ diskpack and put the needed components
onto a floppy (of some sort)?
I'm contemplating attempting to do this myself,
but in case it's been done already, I'd just as
soon as not re-invent the wheel.
I'll need the formatter used with the RQDX3.
BTW-- Anybody have the docs for the DSD-880? Info
on this would be most appreciated.
Jeff
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Speaking of PS/2 memory, can anyone shed any light on the
following MCA memory card:
Made by Quadram. There are various stickers:
[908503] [02790487][REV 1B] [K.B.]
[9080R1] [9081R1] [9079R2]
The [908503] sticker obscures an etch number
17-9085-[908503]R1
There are four 30pin SIMM slots furthest from the back plate,
each containing a 1Mbyte SIMM.
I've searched the web but can't find any info. There are three
3pin jumpers (marked J1, J2, J3) and one toggle switch on
the back plate. I've assumed that the jumpers set the
starting address/size and that the toggle switches it off and
on but can't see any extra memory (even after trying various
combinations) in my PS/2 model 80.
Doug.
>As it happens, the committee did standardize on the one mode bit that makes
>the interface an 8-bitter. How extensively that was adhered to remains to
>be seen, I guess.
Well wishful thinking had me check it out using several 85-130mb drives
(quantum, Seagate, maxtor, WD) and none seem to do that. After all
having that would make the interface a no brainer and save a simple silo
for splitting read and writes. However, it was wishful thinking.
As to doing it on S100, been there done that. the interface logic needed
to do the bus does 3/4s of the work and it only needs a bit more the
close the loop. CPLD/FPGA/PAL could cover most of that but for S100
I like real TTL (244/241/373) like parts and NO cmos where the bis
interface occurs.
Allison
>> I personally like the CMOS much better since it drives harder, and since it
>> pulls and pushes with the same impedance, unlike TTL which sinks 16 and
>> sources 1.6 mA. I've tried replacing all the bus interface buffers on my
>> old S-100 cards with AC logic. In some cases I used HC or AHCT (SAMSUNG)
>I've seen latchup on busses that ring negative using HC and HCT parts.
>I'd like the better drive but they would randomly flame on me due to the
>bus ringing. Obviously loading the bus with terminators would solve this
>but it's still something that worried me and made for a less robust card
>for handling and ESD.
Is the cheapness of IDE drives worth all the heartache of the cable
length and funny line driver limitations? The cable length limitations
are so short that you've almost got to put the hard drive in the same
box as the CPU - this isn't good if you want expandable or flexible systems!
But if "cheap" is the main requirement, I suppose it's OK.
Maybe I'm too used to dealing with systems where the hard drive might
be 60 or 100 feet away from the CPU... (differential SCSI and SMD.)
Tim.
> Is this some sort of rebadged DEC system or a totally custom
>ie: worthless medical gadget....looks promising.
It's a system, with DEC CPU, non-DEC controllers/peripherals and a non-DEC
backplane/chassis/power supply.
Not too unusual - IMHO it's *more* unusual to find an entirely-DEC
system.
Note that it is possible to assemble a brand-new PDP-11 "compatible"
using no DEC parts at all. For instance, I know of one desktop system
using a Mentec M11 CPU (totally custom implementation, not even a J11),
Andromeda SCDC SCSI host adapter, Logical Company async multiplexer, and
a Seagate SCSI hard drive in an Andromeda desktop Q-bus enclosure.
Tim.
My favorite words from a flea market vendor is "I don't know anything
about this stuff... " Just picked up two Timex Sinclairs, Timex 2068
CPU, printer, cassette interface all brand new in the original box's.
$10 for the whole shabang. I wonder if I should send in the
warranties...
Brian.
>Those "special" drives are not what I meant to ask about. I want to know
>more about the 8-bit mode described in the ATA Interface Specification as
>published in 1994 and 1996. This is apparently a "standard" feature.
It was a proposed feature. Not used that I know of and later deleted from
the spec. I've never found a drive that it works on, wish it did though.
Allison