From hedley Fri Jul 27 18:43:03 1990
Received: from WCHEST.DECnet MAIL11D_V3 
	by cbmvax.cbm.commodore.com (5.57/UUCP-Project/Commodore Jan 13 1990)
	id AA04140; Fri, 27 Jul 90 18:42:59 EDT
Date: Fri, 27 Jul 90 18:42:58 EDT
Message-Id: <9007272242.AA04140@cbmvax.cbm.commodore.com>
From: wches3::davis
To: cbmvax::perry, cbmvax::daveh
Status: R

	
	Perry,
		Here is a first cut at a document that is getting
	requested throughout the company. Please review it and provide
	your comments to me. Please do not distribute this as I do not
	want to have to hassle with dealing with inaccurate copies in
	circulation.

	Thanks

	Hedley


	A3000 PCB REV LEVELS	V0.0	( first draft )
	-----------------------------------------------


	A variety of A3000 motherboards and daughtercards have been
	produced. This note outlines the changes made on the
	various prodution versions of the A3000. Boards are identitified
	by a numeric rev level. Increasing the ones digit denotes new
	artwork, while increasing the tenths digit denotes levels of
	rework.


	Note that there are TWO types of boards bearing rev 6.1 markings.
	The first is a board marked with the silkscreen as rev 6 which has
	been reworked to the rev 6.1 level. The second is a board that
	was actually silkscreened as a rev 6.1 board. These boards are
	identical to boards marked rev 7.0, only the silkscreen was 
	corrected.

	Many intermediate revs which never left the factory are seen in
	this list. They are listed here because many internal commodore
	machines may be of that type. Units shipped to end customers 
	are marked.

	Motherboard:
	------------

	Rev 9.0 	****	Shipped to end customers.    ****
		Current production rev.

		No rework required.

	Rev 8.9		****	Shipped to end customers.    ****
		This rev is just like the rev 9.0 artwork, only some
		small changes were made. This rev is actually the
		rev 8 inner layers combined with the rev 9 outer
		layers. This allowed rom towers to be phased out 
		sooner than otherwise possible.

		No rework required.

	Rev 8.0
		No boards of this type were produced. This was intended
		to be a cosmetic change.

		No rework required.

	Rev 7.3		****	Shipped to end customers.    ****
		Indicates that the ROM tower is fastened with wire ties.

		No rework required.

	Rev 7.2	
		indicates that this board has had a rom tower 
		as opposed to EPROMs.

		No rework required.

	Rev 7.1
		These boards had a pull-up wired to the SCSI select line.
		Without this pullup, the system might not boot if no 
		SCSI devices were connected. All A3000s are shipped with 
		a SCSI device built-in ( providing termination ). The only 
		reason to add this jumper was to facilitate production 
		processes that did not want a hard drive attached.

		No rework required.

	Rev 7.0 ( and boards with rev 6.1 silkscreened on them ).

		These boards corrected all known problems with the
		rev 6 boards.

		The SCSI terminators were changed to the defacto standard
 		of 3 8-pin resistor packs. Only sockets were installed
		in the PCB, SCSI termination was not installed on the board.

		Important User Note:

			These boards will not boot without at least one
			SCSI device attached ( such as the internal hard
			drive ). If desired, this can be alleviated 
			by jumpering U800 pin 6 to RP350 pin 4. Adding
			such a jumper would make this board a rev 7.1.
			Note that the this level works great provided
			that a terminated SCSI hard drive is attached.

		No rework required.

	Rev 6.1		****	Shipped to end customers.    ****

		( Silkscreen says rev 6.0 in middle of board, label
		  says rev 6.1 . Note that some rev 7 boards were
		produced that had 6.1 silkscreened on them. These
		are really rev 7 boards. )

		First production boards.

		These can be easily identitfied by a rework wire
		running to the FPU from near the fastram section.

		Important User Note:

			On these units, SCSI termination is mounted directly 
			on the motherboard. Therefore no termination should 
			be attached to the internal drive. All other revs 
			of A3000 have no termination on the motherboard and 
			require one and only one internal SCSI device to 
			be terminated.

		No rework required.

	Rev 6.0
		First production candidate. Included obselete gate arrays,
		bogus system software in EPROMS, illegal sockets for
		84 pin PLCCs, etc. etc....

		The rework required to make these boards functional can
		only be performed at the factory. ( See ECR/ECO WC0101 
		for details ).


	Daughter Card
	-------------

	Rev 7.1		**** 	Shipped to End Customers   ****
		Current production rev. Soon to be replaced with
		rev 8 pcb which will, alledgedly, require no rework.

	Rev 7.0	
		Rev 7 boards where created to eliminate the need for
		+12V jumper to the XT slots. A mistake was made in the
		PCB creation process causeing an inner layer short between
		the +12V & -5V power lines. All of these boards were 
		reworked at the factory.

	Rev 6.1		****	Shipped to end customers.    ****
		No rework required. These are reworked rev 6.0 pcbas.

	Rev 6.0		****	Shipped to end customers.    ****

		This version was created to add components to support
		an alternate product. It was noticed while these boards
		were being manufactured that on this and all previous revs
		of the daughter card, +12V was errantly not connected to 
		the XT expansion slots.

		Required rework:

				+ 12 volts is missing from the XT slots.
				Pin b9 of the XT slot should be connected
				to a source of +12 on the daughter card.

				Mark board rev 6.1


	Rev 5.1		****	Shipped to end customers.    ****

		This is a fully corrected rev 5 pcba.

		No rework required.


	Rev 5.0		****	Shipped to end customers.    ****

		This rev is functionaly identical to rev 4.1. 

		Required rework:

				+ 12 volts is missing from the XT slots.
				Pin b9 of the XT slot should be connected
				to a source of +12 on the daughter card.

				Mark board rev 5.1


	Rev 4.2		****	Shipped to end customers.    ****

		This is a fully corrected rev 4 or rev 3 pcba.

		No rework required.


	Rev 4.1		****	Shipped to end customers.    ****
		This is a correct rev 3 or rev 4 pcb.
		
		Required rework:

				Jumper +12V ( on the daughter card ) to 
				pin B9 on a XT slot.

		Mark the board 4.2

	Rev 4.0	& rev 3.0
		****	Shipped to end customers.    ****

		The only difference between rev 3 & 4 daughter cards is
		the silkscreen. There are no functional differences.

		Required rework:
				Jumper RP603 pin 5 to CN603 pin 51.

				Jumper RP608 pin 2 to CN602 pin 86.
	
				+ 12 volts is missing from the XT slots.
				Pin b9 of the XT slot should be connected
				to a source of +12 on the daughter card.

				Mark board rev 4.2


	Note that no end-user A3000 motherboards require rework. The 
	daughter card may require up to 3 jumpers, depending on the
	vintage. There are also some user issues, things the owner
	should be aware of, if he or she owns a rev 6.x or 7.0 
	motherboard.


	

