Do VMS and ODS-2 really try to figure out a geometry per disk for MSCP
disks???
That just seems extremely stupid. Yes, MSCP disks have spare blocks,
that are not reported in the disk size. However, MSCP in general also do
not have a meaningful geometry. The number of blocks can vary depending
on the track, and with replacement blocks, the physical location of any
block can in fact be almost anywhere on the disk.
I would have expected MSCP disks to just have some fake geometry that
was the same for all disks. After all, you do not address blocks on MSCP
with a cylinder/head/track/block kind of addressing. It's just a block
number.
Johnny
On 2016-03-09 02:47, Timothe Litt wrote:
In the process of debugging the ODS2 utility, it became clear that the
disk geometry really does matter.
And it's not available in simulator images -- or even for physical
devices -- at runtime.
Below is a list of all the disks that have been used with FILES-11
(ODS2) for which I have reliable (I think) data.
The list has blank spots for a lot of disks that I know exist, but for
which I don't have reliable data.
What matters are the sector size (usually 512), sectors/track, tracks
(surfaces)/cylinder, and number of
cylinders. The other columns are computed (and informational).
I have two requests:
1) If you see any errors, please let me know. Gathering this was a
manual process.
2) If you have data for other disks **USED FOR FILES-11 ODS-2**, please
let me know.
I know there were 3rd-party disks that weren't exact clones of the
DEC disks....
FYI: (and to avoid the inevitable questions)
* I do know about the pdp-10 format for Massbus disks shared with the
front end. ODS-1.
* Delta is the distance between HOM blocks for the given geometry
* Capacity is in bytes.
* For this exercise, I need the geometry as presented to the OS, not
the internal organization
E.g. some DSA disks have spare sectors, but (as far as I know),
these aren't accounted for
when a volume is initialized. If you have a physical disk (or image
of one), it's possible
to resolve ambiguities by dumping block 1. (e.g. on VMS,
dump /block=(start=1,count=1) dka100:)
* Most "modern" OSs lie about geometry - to fit into small fields in
the BIOS reports, or
because it just doesn't matter to them. There's no
reliable/portable way to "just ask the
host OS" - or even the hardware.
Thanks.
Name SecSiz Sec/Tk Tk/Cy Cyls Capacity LBNs Delta
RK05 512 12 2 203 2494464 4872 2.379 MB 37
RK06 512 22 3 411 13888512 27126 13.245 MB 89
RK07 512 22 3 815 27540480 53790 26.265 MB 89
RK11 512 12 2 203 2494464 4872 2.379 MB 37
RL01 512 40 2 256 10485760 20480 10.000 MB 121
RL02 512 40 2 512 20971520 40960 20.000 MB 121
RM02 512 32 5 823 67420160 131680 64.297 MB 193
RM03 512 32 5 823 67420160 131680 64.297 MB 193
RP04 512 22 19 411 87960576 171798 83.886 MB 441
RP05 512 22 19 411 87960576 171798 83.886 MB 441
RM80 512 31 14 559 124214272 242606 118.460 MB 466
RP06 512 22 19 815 174423040 340670 166.343 MB 441
RM05 512 32 19 823 256196608 500384 244.328 MB 641
RP07 512 50 32 630 516096000 1008000 492.188 MB 1651
RX50 512 10 1 80 409600 800 0.391 MB 11
RX33 512 15 2 80 1228800 2400 1.172 MB 46
*RD50 ----- ------ ----- ----- ---------- ---------- ----------
RD51 512 18 4 306 11280384 22032 10.758 MB 91
RD31 512 17 4 615 21411840 41820 20.420 MB 86
RD52 512 17 8 512 35651584 69632 34.000 MB 154
RD53 512 17 7 1024 62390272 121856 59.500 MB 137
RD54 512 17 15 1225 159936000 312375 152.527 MB 273
RA82 512 57 15 1423 622932480 1216665 594.075 MB 913
RA72 512 51 20 1921 1003223040 1959420 956.748 MB 1072
*RA80 ----- ------ ----- ----- ---------- ---------- ----------
*RA81 ----- ------ ----- ----- ---------- ---------- ----------
RA82 512 57 15 1435 628185600 1226925 599.084 MB 913
RA90 512 69 13 2649 1216590336 2376153 1160.231 MB 967
RA92 512 73 13 3099 1505766912 2940951 1436.011 MB 1023
RRD40 512 128 1 10400 681574400 1331200 650.000 MB 129
RRD50 512 128 1 10400 681574400 1331200 650.000 MB 129
RX01 128 26 1 77 256256 500 0.244 MB 7
RX02 256 26 1 77 512512 1001 0.489 MB 14
*RX23-SD ----- ------ ----- ----- ---------- ---------- ----------
*RX23-DD ----- ------ ----- ----- ---------- ---------- ----------
RX33-SD 512 10 1 80 409600 800 0.391 MB 11
*RX33-DD ----- ------ ----- ----- ---------- ---------- ----------
RX50 512 10 1 80 409600 800 0.391 MB 11
*RC25 ----- ------ ----- ----- ---------- ---------- ----------
*RF30 ----- ------ ----- ----- ---------- ---------- ----------
*RF31 ----- ------ ----- ----- ---------- ---------- ----------
*RF35 ----- ------ ----- ----- ---------- ---------- ----------
*RF36 ----- ------ ----- ----- ---------- ---------- ----------
*RF71 ----- ------ ----- ----- ---------- ---------- ----------
*RF72 ----- ------ ----- ----- ---------- ---------- ----------
*RF73 ----- ------ ----- ----- ---------- ---------- ----------
*RF74 ----- ------ ----- ----- ---------- ---------- ----------
*RZ22 ----- ------ ----- ----- ---------- ---------- ----------
*RZ23 ----- ------ ----- ----- ---------- ---------- ----------
*RZ24 ----- ------ ----- ----- ---------- ---------- ----------
*RZ25 ----- ------ ----- ----- ---------- ---------- ----------
*RZ26 ----- ------ ----- ----- ---------- ---------- ----------
*RZ27 ----- ------ ----- ----- ---------- ---------- ----------
*RZ28 ----- ------ ----- ----- ---------- ---------- ----------
*RZ29 ----- ------ ----- ----- ---------- ---------- ----------
*RZ31 ----- ------ ----- ----- ---------- ---------- ----------
*RZ33 ----- ------ ----- ----- ---------- ---------- ----------
*RZ35 ----- ------ ----- ----- ---------- ---------- ----------
*RZ55 ----- ------ ----- ----- ---------- ---------- ----------
*RZ56 ----- ------ ----- ----- ---------- ---------- ----------
*RZ57 ----- ------ ----- ----- ---------- ---------- ----------
*RZ58 ----- ------ ----- ----- ---------- ---------- ----------
*RZ59 ----- ------ ----- ----- ---------- ---------- ----------
*RZ72 ----- ------ ----- ----- ---------- ---------- ----------
*RZ73 ----- ------ ----- ----- ---------- ---------- ----------
*RZ74 ----- ------ ----- ----- ---------- ---------- ----------
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--
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|| on a psychedelic trip
email: [email protected] || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
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