To:	Dave, Mark, Norm, Ron, Brad
From:	Chris
Re:	Distribution Tape Format
________________________________________________________________________________________________________________________________________

This note describes an improved scheme for distributing software, and the proposed format of a release tape.  Currently we have too many tapes:

	DOM:V10Q10.25		Domestic 010 1/4 inch
	DOM:V20Q10.25		Domestic 020 1/4 inch
	DOM:V10Q10.5/1		Domestic 010 1/2 inch part 1 of 2
	DOM:V20Q10.5/1		Domestic 020 1/2 inch part 1 of 2
	DOM:.5/2		Domestic 1/2 inch part 2 of 2
	INT:V10Q10.25		International 010 1/4 inch
	INT:V20Q10.25		International 020 1/4 inch
	INT:V10Q10.5/1		International 010 1/2 inch part 1 of 2
	INT:V20Q10.5/1		International 020 1/2 inch part 1 of 2
	INT:.5/2		International 1/2 inch part 2 of 2

The current order of files on the release tape is:

	0:	V10	copy		V20	copy
	1:	V10	mem		V20	mem
	2:	V10	mmu		V20	mmu
	3:	V10	diskread	V20	diskread
	4:	V10	disktest	V20	disktest
	5:	V10	dma		V20	dma
	6:	V10	bad144		V20	bad144
	7:	V10	diskformat	V20	diskformat
	8:		Q10	copy
	9:		Q10	mem
	10:		Q10	mmu
	11:		Q10	diskread
	12:		Q10	disktest
	13:		Q10	dma
	14:		Q10	bad144
	15:		Q10	diskformat
	16:			mini-root
	17:			dump of root		{DOM/INT}
	18.25:			tar of usr		{DOM/INT}
	19.25:			tar of usr (man, doc, etc...)
	18.5:			tar of usr part 1 	{DOM/INT}
	19.5-0.5/2:		tar of usr part 2 		[on tape 2]
	20.5-1.5/2:		tar of usr (man, doc, etc...)	[on tape 2]
	

I have added the ability in the standalone ts driver to boot out of file systems on tape (even with old QIC2 PROMS, which do not support the skip 
record reverse command correctly).  The allows us to get rid of V10Q10 vs V20Q10 differences in the release tape, and also allows us to add diagnostics 
to the release tape without disturbing the order of files on the tape (no major documentation changes).  Effectively, we can have a "diagnostic root" 
on tape which contains three directories: Q10, V10, V20.  These directories contain all diagnostics and standalone programs for the specified cpu.  
The 'copy' program also can be in the diagnostic root.  The penality for using the file_system_on_tape approach is that there is a lot of repositioning 
done increasing the time it takes to load a diagnostic.  If you are going to run lots of diagnostics however, you can boot standalone copy from the 
diagnostic root and copy the diagnostic root to the disk (similar to copy of mini-root); thereafter booting all diagnostics from the disk.

As an example, to boot copy for the Q10 you had to type:

	: ts(0,8)

Now you would type:

	: ts(0,0)Q10/copy

The number of tapes would be almost cut in half:

	DOM:.25			Domestic 010 1/4 inch
	DOM:.5/1		Domestic 010 1/2 inch part 1 of 2
	DOM:.5/2		Domestic 1/2 inch part 2 of 2
	INT:.25			International 010 1/4 inch
	INT:.5/1		International 010 1/2 inch part 1 of 2
	INT:.5/2		International 1/2 inch part 2 of 2

The order of files on the tape would be simplified considerably:

	0:	diagnostic_root
	1:	mini_root
	2:	dump of root		{DOM/INT}
	3:	tar of usr		{DOM/INT}
	4:	tar of usr (man, doc, etc...)

If, on the half inch, we made sure the the DOM/INT differences were only on the first of the two tapes, we would end up with the following 5 tapes:

	DOM:.25			Domestic 010 1/4 inch
	DOM:.5/1		Domestic 010 1/2 inch part 1 of 2
	INT:.25			International 010 1/4 inch
	INT:.5/1		International 010 1/2 inch part 1 of 2
	.5/2			1/2 inch part 2 of 2
