Subject: Data Systems Design DSD-880 8" floppy and hard drive?

From: Joe <[email-masked]>
Date: Mon Jul 21 15:14:26 2003

Anybody know anything about a DSD-880 8" floppy and hard drive unit made
by Data Systems Design? (Black rack mount box about 6" high and 28" deep.)
I found several of them today. I'm pretty certain that they came off of a
system tester or circuit board tester based on a DEC computer. The units
had a Shugart 800-1 8" SSDD floppy drive and a Quantum Q2040 8" hard drive
in them and a INTERESTING looking front panel that said "Hyper Diagnostics"
or something like that.

   I bought a HUGE lot of 8" floppy disks from the same place. They almost
certainly came from the same systems. The disks contained RT-11 and RSX. I
found that some of the disks had the driver and diagnostics for the
DSD-880. Also found copies of distribution disks for RT-11 and RSX in the
same pile.

    Joe

---

From: Bob Shannon <[email-masked]>
Date: Mon Jul 21 16:19:25 2003

Yep, very common, and once popular 3rd party storage for DEC machines.

I think I have schematics for the controller around here, an 8X300 based 
machine I think.

---

From: "Stuart Johnson" <[email-masked]>
Date: Mon Jul 21 17:01:19 2003

----- Original Message ----- 
From: "Joe" <[email-masked]>
To: <[email-masked]>
Sent: Thursday, July 17, 2003 8:53 PM
Subject: Data Systems Design DSD-880 8" floppy and hard drive?

> DSD-880. Also found copies of distribution disks for RT-11 and RSX in the

Joe,

I had one of these boards connected to a pair of Qume (851) drives back in
the early 80's. They worked GREAT, could read, write, and format RX01, RX02,
and with a modified driver, did DSDD for about 1.2mb per floppy!

I wish I had one of these controllers now (I have a pair of 8" drives).

Regards,
Stuart Johnson

---

From: Joe <[email-masked]>
Date: Mon Jul 21 17:05:01 2003

>I wish I had one of these controllers now (I have a pair of 8" drives).

   Carefull what you wish for, it could come true!

   Seriously I can get the chassis if you want one (or both). But I've
already grabbed the drives out of them. Both had one Shugart floppy drive
and an 8" hard drive in them. One had a WD1004 hard drive and the other had
a Quantum Q2040. I'm not sure if the floppy drive in them was  SS or DS. I
just grabbed the drives and they were mixed up with other similar drives.
But I ended up with one DS drive and about 10 SS ones so they most likely
had SS drives in them. I also don't know if the controller/interface card
that goes in the computer is still around or not. There are (were?) a
couple of chaasis there with DEC cards in them but I have no idea which
card(s) are needed for the drive system or if the necessary card(s) are there.

    Joe

---

From: "Jerome H. Fine" <[email-masked]>
Date: Mon Jul 21 17:24:04 2003

>Stuart Johnson wrote:

> and with a modified driver, did DSDD for about 1.2mb per floppy!

Jerome Fine replies:

Which operating system had the modified drivers?  I use RT-11
and DEC never bothered to write a driver for an RX03.

> I wish I had one of these controllers now (I have a pair of 8" drives).

There are controllers available for the DSD-880 which interface
on the Qbus for both the RX03 and the 8" hard drive.  Unfortunately,
the current hardware set-up handles only ONE  RX03 in addition
to the 8" hard drive.

Sincerely yours,

Jerome Fine
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---

From: "Stuart Johnson" <[email-masked]>
Date: Mon Jul 21 17:27:02 2003

----- Original Message ----- 
From: "Jerome H. Fine" <[email-masked]>
To: "Stuart Johnson" <[email-masked]>; <[email-masked]>
Sent: Sunday, July 20, 2003 7:15 PM
Subject: Re: Data Systems Design DSD-880 8" floppy and hard drive?

> the current hardware set-up handles only ONE  RX03 in addition

Jerome,

The v4.0 distribution of RT-11 comes with source to the DY driver (RX02),
which has "commented out" code for DSDD operation, that as best as I can
remember, almost works. Until about 2 years ago I still had the floppy with
the source, but I determined that I would never need that "stuff" again
and - you guessed it - threw it away. As I recall, it was relatively easy to
make it work and it maintained compatibility with the RX01 and RX02 formats.
As I understand it, the RT-11 v5 code completely removed the DSDD code.

At the time I did this, I had been building multi-terminal RT-11 monitors,
written a driver for a BCU-11 MIL-STD 1553 controller, and installed
TSX-Plus. I was pretty "up" on programming RT-11 at that time. I had also
written a Fortran program to read a UCSD P-system disk and write selected
files to a CP/M disk, helping me to learn about sector interleave.

In case you and any other readers are wondering, yes, I have regretted
throwing away the RT-11 media distribution kit, the working floppies for
RT-11, my "enhanced" drivers and the one I wrote from scratch - about a
thousand times since I did it.

Regards,
Stuart Johnson

---

From: Bob Shannon <[email-masked]>
Date: Tue Jul 22 19:38:46 2003

RT-11, the DSD boxes cannot use stock DEC drivers.

---

From: "Jerome H. Fine" <[email-masked]>
Date: Tue Jul 22 20:04:30 2003

>Bob Shannon wrote:

Jerome Fine replies:

I believe you are incorrect.  The extra detail is as follows:

The DSD boxes can use BOTH the hard drive (emulating
an RL01 for the 8 MByte hard drive or 3 * RL02 for
the 30 MByte hard drive) and the single 8" floppy drive
(emulating an RX02) with stock (distributed) device
drivers.  I have done so with BOTH V4.00 and V5.03
distributions of RT-11.

I agree there needs to be a SYSGEN to be able to use
all 3 * RL02 drives with the DL(X).SYS device drivers
and the hardware handles ONLY 18 bit addresses for
both the DYX.SYS  and DLX.SYS device drivers.

BUT the RLV11 and the RXV12 from DEC also
managed to handle only 18-bit addresses.  So the
DSD box was completely compatible with the stock
(distributed) V4.00 of RT-11.

However, V4.00 code in DY.MAC contained the
extra instructions to use a double-sided media which
would probably have been called an RX03.  And
although those extra instructions had bugs (after all
they had never been tested) and were removed by
V5.00 of RT-11, I did fix the bugs and ran a DYX.SYS
device driver under V5.03 of RT-11 using the DSD
8" floppy as a double-sided drive.  In addition,
I also added a bounce buffer in DYX.SYS so that
a user buffer above 256 KBytes could be used
with the 18-bit hardware addresses in the floppy.

I would appreciate any replies, especially ones which
correct the above information and what I actually
did with the DSD hardware and the RT-11 software.

Sincerely yours,

Jerome Fine

---

From: Joe <[email-masked]>
Date: Tue Jul 22 20:24:02 2003

At 11:25 PM 7/21/03 -0400, you wrote:
>I believe you are incorrect. 

   I can settle this. I have the RT-11 and all the other disks from the
syustem. If anyone is interested they can take the disks and find out how
they were controlling the DSD devices.

    Joe

---

From: Bob Shannon <[email-masked]>
Date: Wed Jul 23 19:19:00 2003

>drivers.  I have done so with BOTH V4.00 and V5.03

The DSD boxes I used do not emulate DEC drives, and made the 45 meg hard 
drive
available as a single device.

I have, err, well, Jay West has a DSD floppy-only (RX-02) emulation in 
his 11/34a out
in my garage, and that does use the standard driver.

I guess DSD had many varients, and we must be talking about different 
products.

But the unibus version of the DSD interface for the floppy-hard drive 
combo's I've
worked with all needed a DSD driver for RT-11.

I ~think~ the DSD driver exists, on a LINC tape (Jay's got a Computer 
Operations LINC
tape drive, which also uses a non-standard driver).  For some time, that 
machine could not
be upgraded to a newer version of RT-11 because the LINC tape driver 
would not assemble
correctly under the newer version (I cannot, for the life of me recall 
which versions these were!).

Something about an interrupt function call....sorry, its been too long, 
and I've forgotten the
details.  Anyway, all the 'funky' drivers and their source was saved on 
a LINC tape, which I loved
using more than the newer version of RT-11.  

That 11/34a system has accumulated a strange set of peripherals saved 
from the decommissioning
of a long series of very choice Unibus hardware, starting with a DEC 
Graphic 11/40, then an 11/T55, and
an 11/60.  I got rid of all of that, keeping only an 11/35 and the 11/34 
due to size.  Now only the 11/34
remains, and thats Jay's.

Maybe once Jay actually gets this stuff, and gets it all put together, 
he will find a stack of odd drivers and
their soruce code on one of the LINC tapes?

---

From: "Jerome H. Fine" <[email-masked]>
Date: Wed Jul 23 19:32:43 2003

Jerome Fine replies:

As far as I know, the DSD 880/8 and the DSD 880/30 all used
only a Qbus controller.  And they accepted the standard DEC
device drivers in RT-11.

There may have been other DSD boxes in addition the the DSD 880
and DSD 440, but I had not heard about them, let alone the details.

> in my garage, and that does use the standard driver.

That was the DSD 440 which emulated the RX02.  For this drive,
I used BOTH a Unibus controller on a PDP-11/34 and a Qbus
controller on an LSI-11 within a VT103.  What I found MOST
amazing at the time (1979) was that the same RX02 floppy would
BOOT on BOTH the Unibus and the Qbus systems even though
the hardware was so different - especially the CPUs.  RT-11
was able to self-configure on the fly to whichever hardware was
present during the boot phase.

> I guess DSD had many varients, and we must be talking about different

Seems like it.  BUT the header stated DSD 880, so I went along
with it.  Any idea what the actual hardware was?

> worked with all needed a DSD driver for RT-11.

Again, was that a DSD 880/8?  If so, DSD did provide a driver
for the RL02 interface which normally used 10 MBytes to allow
for the 8 MByte hard drive.  I don't feel that this was a special
DSD driver that was essential since the standard DL(X).SYS
could be used with the DSD 880/8 to give a 5 MByte usage
of the hard drive as an RL01 drive.  That meant that 3 MBytes
were lost to the user, but it would still work with the standard
distributed DEC  RT-11 device driver.

Sincerely yours,

Jerome Fine

---

From: Joe <[email-masked]>
Date: Wed Jul 23 20:29:54 2003

>and DSD 440, but I had not heard about them, let alone the details.

   FWIW I was looking through my Intel docs last night and found a manual
for a DSD Multibus hard drive controller.

   Joe

---

From: Bob Shannon <[email-masked]>
Date: Wed Jul 23 21:59:57 2003

>only a Qbus controller.  And they accepted the standard DEC
Oh no, there is a unibus DSD controller, I'm absolutley positive about 
this.  I've owned two, and serviced
a great many back in the Eli Heffron days.

>distributed DEC  RT-11 device driver.
All my DSD experiance is unibus based.  Qbus machines have no 
blinkenlights, and are in my eyes,
unworthy.

---

From: Megan <[email-masked]>
Date: Sat Jul 26 20:59:28 2003

>they were controlling the DSD devices.

I can settle this... The RT development group had mostly 11/23-based
systems using DSD880s of various types for a number of years, and we
ran the stock RT-11 system on them just fine.

As Jerome has pointed out, if we needed to use the additional RL of
an 880/30, we had to rebuild the DL handler, and the code was there
in the DY driver, though we typically didn't use it.

In addition, I can say that the P/OS development group used DSD880s
on 11/23-based systems to develop P/OS in the early days -- there was
a qbus board which they used to do the P/OS graphics.  It was
programmed almost identically to what was eventually in the PRO.

                                        Megan Gentry
                                        Former RT-11 Developer

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