Chuck(G)
25k Member
On the RX50 disks used in both the DECMate II and III there appears to be a substantial difference in recording format.
The DM II WPS records 12 bits out of 16, but DM III WPS appears to not clear 4 bits in the second byte. For example:
DM II WPS:
Am I reading this correctly? Note that the block header bytes are the same in both cases and, in particular note the byte stream at offset 70h:
Is this due to a missing instruction in the write loop of the DM III?
The DM II WPS records 12 bits out of 16, but DM III WPS appears to not clear 4 bits in the second byte. For example:
DM II WPS:
Code:
00001400 00 00 02 00 08 08 08 e7 00 01 00 00 00 00 00 00 |................|
00001410 00 00 ff 09 ff 09 ff 09 ff 00 28 00 31 00 21 0a |..........(.1.!.|
00001420 2b 04 2b 0b 0e 07 2b 08 14 0a 07 04 3a 0a 44 0b |+.+...+.....:.D.|
00001430 32 00 ed 0d 2c 0a c0 0e ec 0d 11 0a 08 0f 11 06 |2...,...........|
00001440 1a 0b 10 02 0f 06 29 06 29 0a 2b 08 0e 07 23 0a |......).).+...#.|
00001450 c5 0e 31 02 49 06 20 0e 07 06 01 0e 06 06 44 0b |..1.I. .......D.|
00001460 c7 0e 49 02 e9 0d d5 0e 06 02 2b 08 06 06 c1 0e |..I.......+.....|
00001470 2b 08 2b 08 80 00 00 01 49 02 e9 0d 15 0a 12 00 |+.+.....I.......|
00001480 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
[/code}
DM III WPS:
[code]
00001400 00 00 02 00 08 08 08 e7 00 01 00 00 00 00 00 00 |................|
00001410 00 00 ff 79 ff 79 ff 79 ff 70 28 20 31 30 21 2a |...y.y.y.p( 10!*|
00001420 2b 24 2b 2b 0e 07 2b 28 14 1a 07 04 3a 3a 44 4b |+$++..+(....::DK|
00001430 32 30 ed 6d 2c 2a c0 4e ec 6d 11 1a 08 0f 11 16 |20.m,*.N.m......|
00001440 1a 1b 10 12 0f 06 29 26 29 2a 2b 28 0e 07 23 2a |......)&)*+(..#*|
00001450 c5 4e 31 32 49 46 20 2e 07 06 01 0e 06 06 44 4b |.N12IF .......DK|
00001460 c7 4e 49 42 e9 6d d5 5e 06 02 2b 28 06 06 c1 4e |.NIB.m.^..+(...N|
00001470 2b 28 2b 28 80 00 00 01 49 42 e9 6d 15 1a 12 10 |+(+(....IB.m....|
00001480 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
Am I reading this correctly? Note that the block header bytes are the same in both cases and, in particular note the byte stream at offset 70h:
Code:
DM II:
2b 08 2b 08 80 00 00 01
DM III:
2b 28 2b 28 80 00 00 01