RLV11/RL02 ->11/73?

From: CLASSICCMP_at_trailing-edge.com <(CLASSICCMP_at_trailing-edge.com)>
Date: Sun Apr 4 11:10:54 1999

>Zane H. Healy wrote:
> >I'e done it with both using the correct backplanes. As I remember the
> >SMS1000 is a bit strange in the boot deperatment.
Jerome Fine replies:
>My box has a single 8" floppy which is DSDD in capacity for a total of
>1976 blocks. The drive is also set up the detect SSDD floppy media
>as well as DSSD and SSSD media. BUT, the device type is for the
>MSCP emulation. AND the DSDD interface switches from side 1 to
>side 2 for each cylinder (or track since there is only one double-sided
>surface) within the firmware. Since this behaviour is outside the control
>of the device driver (MSCP is DU:), the use of DSDD media is quite
>a surprise as compared to the RX03 implementation on a DSD
>880/30 which uses the same floppy media, but uses the whole first
>side of the media followed by the second side of the media as
>programmed within the DY(X).SYS software device driver in
>RT-11.

These block-numbering issues are addressed by Chester Wilson's
"DYC" handler, to an extent. To quote from the documentation:

*This handler is designed for Sigma/Dilog RX03 controllers, with optional
*assembly for DEC, MTI, and DSD ones. It may need minor modification
*(notably to the extended addressing and formatting code) for other
*manufacturers' boards.
*...
*In version 4, support for the SMS flavour of RX03 format has been added
*(courtesy of discs from Billy Youdelman).

Sources to this code are available at

http://metalab.unc.edu/pub/academic/computer-science/history/pdp-11/rt/billy/ducm5d_dsk/

This code also knows how to format completely blank floppy disks into
DEC-compatible RX01 or RX02 on many third-party controllers under RT-11/TSX.

>As soon as I finish my tax returns and clean up a few other
>things

Don't you have till April 30th up there? (I have to get the
Canadian forms for the money I earned in Canada last year, still...)

-- 
 Tim Shoppa                        Email: shoppa_at_trailing-edge.com
 Trailing Edge Technology          WWW:   http://www.trailing-edge.com/
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Received on Sun Apr 04 1999 - 11:10:54 BST

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