Thanks for your comments! I guess what confused me was that both DX.SYS
and DY.SYS are present on my RX01 distribution disk 1. Maybe the
problem is that whatever is written by COPY/BOOT isn't compatible with
the RX02 drive? As you suggest, I can read the RX01 media fine once
I've booted off of an RX02 disk.
In any case, I've gotten past this problem and now have a bootable RX02
disk with RT-11 V5 and the DECUS C compiler. I'm working on getting
Kermit copied over.
On Dec 2, 2004, at 10:49 AM, Jerome H. Fine wrote:
> >David Betz wrote:
>
>> Oops. I made a mistake in my original post. The command I typed to
>> copy the distribution disk was:
>>
>> SQUEEZE/WAIT/OUTPUT:DY1: DY0:
>>
>> That's what the installation instructions say to do anyway.
>>
>> I've actually gotten a boot disk created now. It seems that the V4
>> version of RT-11 I was originally using didn't really do the
>> COPY/BOOT command correctly. I found another V4 boot disk and was
>> able to use it to create a bootable V5 disk. I now have RT-11 V5 and
>> the DECUS C compiler and linker all on one disk. This is something I
>> could never do with my old PDT-11/150. It only had RX01 floppies and
>> all that won't fit on a single density floppy. It's nice to have a
>> bit more space with RX02 drives!
>
> Jerome Fine replies:
>
> Even though the CSR/VECTOR addresses of RX01 and RX02
> drives are the same, they are VERY different programs
> with regard to the device drivers, DX.SYS and DY.SYS,
> respectively. Thus, an RX01 bootable floppy can't
> boot in an RX02 drive and visa versa.
>
> HOWEVER, although it is NOT possible to read an RX02
> floppy (with double density data or 988 blocks on the
> floppy) on an RX01 drive, it is possible and NORMAL
> to read an RX01 floppy (with single density data or
> 494 blocks on the floppy) on an RX02 drive.
>
> You probably understand this now, but other RT-11 users
> may not.
>
> In addition, the device driver for the PDT is again
> different (as far as I understand) from the RX01 device
> driver even though the media is the same (again as far as
> I understand). NOTE that I have never used a PDT system.
>
> As for more recent distributions of RT-11 up to V05.03
> of RT-11, they are available at:
> http://www.classiccmp.org/PDP-11/RT-11/dists/
>
> If you can manage to have a hard disk drive with
> the PDP-11/23, that makes like even better. While
> a SCSI host adapter is still expensive, SCSI drives
> are not. An RQDXn controller is low in cost, but
> decent compatible hard drives are hard to find.
> Don't try to use an RD53 since they are no longer
> reliable. RD52 drives are still OK, as are RD51
> drives which are just 10 MByte Seagate ST-412 drives.
>
> How you transfer them to your PDP-11/23 is a problem
> I can't help you with. For myself, I use the MSCP
> device driver, DU.SYS, which I have on both a PC
> (under E11 with a Sony SMO S-501 and an Adaptec
> AHA-2904AU) and the real DEC hardware (with a the
> CQD-220/TM host adapter and the same SMO S-501).
>
> In addition, DSD produced an RX03 compatible
> floppy media which is able to use RX02 media
> PLUS double sided RX02 compatible media. While
> DEC never did correct the code in DY.MAC to allow
> for double sided drives (it was present in V04.00
> of RT-11), a DYX.SYS device driver is available
> which handles RX03 media on the DSD which also
> allows the use of memory beyond the 256 KByte
> boundary via a bounce buffer. It is also possible
> to re-wire a DSD drive so that single-sided media
> are used rather than punching the extra holes in
> the floppies when the user wants to use both sides
> of the floppy. A DPDT switch allows the user to
> select how the floppy is used.
>
> If you have any RT-11 questions, please ask!
>
> Sincerely yours,
>
> Jerome Fine
> --
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Received on Thu Dec 02 2004 - 10:09:23 GMT