DUMPER tape format - Revision history

Larsbrinkhoff: /* TAPE HEADER */ Format 5-6 has seven more fields.

2025-01-22T11:57:23Z

TAPE HEADER: Format 5-6 has seven more fields.

@@ Line 124: / Line 124: @@
 |-
 | 7
-| "BFMSG" - offset from header to start of saveset name?
+| "BFMSG" - offset from header to start of saveset name.
 |-
 | 8
 | [[Timestamp]] for saveset.
 |-
 | 6+BFMSG

2022-04-27T10:29:37Z

DATA RECORD: It's all file data.

← Older revision		Revision as of 10:29, 27 April 2022
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	===DATA RECORD===		===DATA RECORD===

			All 512 words after the header is file data.

	===TAPE HEADER===		===TAPE HEADER===

2022-04-27T10:16:37Z

FILE HEADER: More info.

← Older revision		Revision as of 10:16, 27 April 2022
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	===FILE HEADER===		===FILE HEADER===

	In format 0, the only file header data is an ASCIZ string in the format ~~DEV~~:<DIRECTORY>NAME.TYPE;VERSION;~~P123456~~;~~AUSER~~.		In format 0, the only file header data is an ASCIZ string in the format ''DEVICE''''':<'''''DIRECTORY'''''>'''''NAME'''''.'''''TYPE''''';'''''VERSION''''';P'''''PROTECTION''''';A'''''ACCOUNT''.

			The ''DEVICE''''':''' part is optional. The ''NAME'' and ''TYPE'' strings can be up to 39 characters. ''VERSION'' is the generation number. ''PROTECTION'' is six octal digits. ''ACCOUNT'' is not the user name, but for accounting purposes.

	Other formats use a period instead of semicolon before the version, and have an FDB (file descriptor block) at offset 0200 (octal) from the record header.		Other formats use a period instead of semicolon before the version, and have an FDB (file descriptor block) at offset 0200 (octal) from the record header.

2022-04-27T07:25:11Z

RECORD HEADER: Update MINI-DUMPER sequence numbering.

← Older revision		Revision as of 07:25, 27 April 2022
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	The [[checksum]] is computed over all 518 words in the record, with the checksum set to 0. For formats 0-4, it's a [[one's complement]] sum. For format 5-6, it the sum is first rotated one step to the left and then adding in the data. The finished checksum is bit-wise inversed before being stored in the header.		The [[checksum]] is computed over all 518 words in the record, with the checksum set to 0. For formats 0-4, it's a [[one's complement]] sum. For format 5-6, it the sum is first rotated one step to the left and then adding in the data. The finished checksum is bit-wise inversed before being stored in the header.

	MINI-DUMPER expects the sequence number to start with 2, whereas later versions begin with 1. ~~Normally each~~ record increments the sequence number by 1~~, but a~~ MINI-DUMPER tape ~~header increments~~ it ~~by 2~~.		MINI-DUMPER expects the sequence number to start with 2, whereas later versions begin with 1. Each record increments the sequence number by 1; MINI-DUMPER also have tape marks increment it.

	{\| class="wikitable"		{\| class="wikitable"

2022-04-15T06:56:48Z

FILE HEADER

← Older revision		Revision as of 06:56, 15 April 2022
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	In format 0, the only file header data is an ASCIZ string in the format DEV:<DIRECTORY>NAME.TYPE;VERSION;P123456;AUSER.		In format 0, the only file header data is an ASCIZ string in the format DEV:<DIRECTORY>NAME.TYPE;VERSION;P123456;AUSER.

	Other formats have an FDB, file descriptor block at offset 0200 (octal) from the record header.		Other formats use a period instead of semicolon before the version, and have an FDB (file descriptor block) at offset 0200 (octal) from the record header.

	===FILE TRAILER===		===FILE TRAILER===

2022-04-15T06:54:21Z

TAPE TRAILER: I see no data here.

← Older revision		Revision as of 06:54, 15 April 2022
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	===TAPE TRAILER===		===TAPE TRAILER===

			This record only marks the end of the saveset and has no data. After this record there should be a tape mark to end the file.

	===USER DIRECTORY===		===USER DIRECTORY===

2022-04-15T06:50:41Z

FILE TRAILER

← Older revision		Revision as of 06:50, 15 April 2022
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	===FILE TRAILER===		===FILE TRAILER===

			The data is the FDB, file descriptor block. In format 0, this is 25 (octal) words. Newer format has 30 (or more?) words.

	===TAPE TRAILER===		===TAPE TRAILER===

2022-04-15T06:44:43Z

TAPE HEADER

← Older revision		Revision as of 06:44, 15 April 2022
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	===TAPE HEADER===		===TAPE HEADER===

	In format 0, the data is just an [[ASCIZ]] saveset name.		In format 0, the data is just an [[ASCIZ]] saveset name at record offset 6.

	If format 4, the data is:		If format 4, the data is:

2022-04-14T14:16:52Z

TAPE FORMATS

← Older revision		Revision as of 14:16, 14 April 2022
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	===TAPE FORMATS===		===TAPE FORMATS===

	There is a tape format number stored in the tape header. It ~~more or less~~ corresponds to the TOPS-20 release. MINI-DUMPER is retroactively assigned format number 0, and doesn't have the format number stored in the tape header.		There is a tape format number stored in the tape header. It corresponds roughly to the TOPS-20 release. MINI-DUMPER is retroactively assigned format number 0, and doesn't have the format number stored in the tape header.

	{\| class="wikitable"		{\| class="wikitable"

2022-04-14T14:16:05Z

TAPE FORMATS: Match format number to operating system releases.

← Older revision		Revision as of 14:16, 14 April 2022
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	\| Format		\| Format
	\| Description		\| Description
			\| Used by
	\|-		\|-
	\| 0		\| 0
	\| [[Bolt, Beranek, and Newman\|BBN]] original MINI-DUMPER format.		\| [[Bolt, Beranek, and Newman\|BBN]] original MINI-DUMPER format.
			\| TENEX
	\|-		\|-
	\| 3		\| 3
	\| FDB changes, structures, "full dir spec".		\| FDB changes, structures, "full dir spec".
			\| TOPS-20 V2, V3A
	\|-		\|-
	\| 4		\| 4
	\| New GTDIR blocks. Lowest legal format for latest DUMPER.		\| New GTDIR blocks. Lowest legal format for latest DUMPER.
			\|
	\|-		\|-
	\| 5		\| 5
	\| Encrypted passwords and other "CRDIR%iods".		\| Encrypted passwords and other "CRDIR%iods".
			\|
	\|-		\|-
	\| 6		\| 6
	\| "TONEXT" record type.		\| "TONEXT" record type.
			\| TOPS-20 V6, V7
	\|}		\|}