DQ614 and other Q-Bus questions

From: Pete Turnbull <pete_at_dunnington.u-net.com>
Date: Mon Aug 10 13:12:26 1998

On Aug 10, 6:42, Ethan Dicks wrote:
> Subject: Re: DQ614 and other Q-Bus questions
> On Sun Aug 9, 15:20, Zane H. Healy <healyzh_at_ix.netcom.com> wrote:

> > Hmmmm, now this sounds ponentially very cool! According to the Field
Guide
> > this is a "Dilog ST-506 emulation of four RL01/02".

Yes, it is. I think I might have been responsible for that highly
informative entry ;-)

> > Any one have info on
> > this, and will it work in a system that has actually RL02 drives
attached?
> > It would make it a lot easier to get data on to the Hard Drive if I can
> > just copy it from a RL02 to a fake RL02.
>
> Presuming that it can be strapped at the alternate address (DLB0 on a
uVAX,
> for example. Dunno the CSR), it should work fine.

It needs a different PROM to switch the address/vector. The standard PROM
at U38 is labelled 91265D (according to my old notes) and the
alternate-address PROM is labelled 91578A (old notes again). YMMV :-)

> > What kind of Hard Drives will work with it?
>
> The one I have used to have a Rodime 10 Mb 5.25" full-height MFM drive
> attached to it. I'd love to hear if an ST-251 would work.

Again, it should. It should be capable of using up to two ST-412 interface
drives to emulate up to four RL02s, though I never tried mine with more
than one. IIRC there's a small overhead, so you need slightly more than
20MB to emulate two drives.

> > Is there any kind of setup for it? There is a funky 20-pin connecter
> > marked J3 that might be for jumpers or a ribbon cable though I don't
really
> > want to try to attach a ribbon cable to it, as it's rather wierdly
attached.
>
> It's an ST-506 interface - 20 pin for analog data (one per drive, up to 4
> supported, depending on the exact nature of the controller in question),
> and 34 pin (digital signals) for control (one per controller, including
> up to 4 drive select wires).

Two physical drives, in this case.

> > Does it have any kind of boot ROMs?
>
> Almost certainly not. It is a register-level emulation of the RLV11 or
RLV12
> (don't know which one). It would use the regular DL boot ROM on your
system.

It does have a bootstrap, but I think the emulation is RLV11 (it's to old
to be RLV12, I think). You can switch the bootstrap off, though. The code
will boot either a DY or DL device.

> > Any idea on how well it would co-exist with a DQ606?
>
> No idea.

Me neither. I don't have the full docs, just a pair of layout diagrams,
switch table, and a few bits about formatting. Unfortnately, all the
formatting stuff seems to use a program which I don't think I have handy.

At the back end of the board is either a 34+20 pin connector, or two
individual headers. As Ethan said, the 34-way is the control bus
(daisy-chained like floppies for multiple drives) and the 20-way is the
data. J3 is the second 20-pin data connector (for the second physical
drive). Pin 1 of the 34-way connector is the end nearest the LED, and the
other connectors are fitted in the same orientation.

There are five switches:

S1 ON = ECC used to transparently correct errors where possible
    OFF = ECC ignored; used for diagnostics
S2 ON = bootstrap enabled
    OFF = bootstrap disabled
S3,S4 Identify the last logical RL unit on physical drive 0. So
          the settings are as follows:

     S3 S4 Physical 0 Physical 1
     off off DL0 Dl1, DL2, DL3
     off on DL0, DL1 DL2, DL3
      on off DL0, DL1, DL2 DL3
      on on DL0, DL1, DL2, DL3

S5 ON = use secondary address for bootstrap ROM: 175000
    OFF = use primary address for bootstrap ROM: 173000

Factory setting is all switches off.

There are 10 jumpers:

JP1 (near U22) removed (etch cut) allows data loopback for diagnostics.
JP2 (near U32) removed (etch cut) aborts controller pre-comp logic when
               writing, for diagnostics.
JP3,4,5 (near U70) sets interrupt levels:

               level JP3 JP4 JP5
                 4 B-C B-C B-C
                 5 B-C B-C A-B
                 6 B-C A-B B-C
                 7 A-B A-B B-C

JP6 (near U22) "Must be removed"
JP7 (near U22) "Must be removed"
JP8 (near U5) "Must be removed"
JP9 (near U32) "Must be installed"
JP (near U32) "A-B must be installed, A-C must be removed"

There's also a socket for a special (customer) bootstrap at U38.

That's about all I can tell you, I'm afraid. I'll have a look for a copy
of the formatting program (which came on an RT11 floppy, I think) but I'm
not hopeful... I don't have the controller any longer.

-- 
Pete						Peter Turnbull
						Dept. of Computer Science
						University of York
Received on Mon Aug 10 1998 - 13:12:26 BST

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