P5.1 upgrade instructions

[Jan Isley]

Last summer, I announced that I had the P5.1 upgrade instructions.
To refresh your memory, I got them from someone who worked on the project
at CT.  The agreement was that he would refer all inquiries to me and I
would make them available to interested parties.  His privacy is increased
and we get the goodies...seems okay to me.

After much deliberation and the soon to be released 2nd disk drive upgrade
that will require this modification, I have decided to post the instructions.
The only reason that I can think of why this information should not be posted
is to save people from trying to do this that are not technically capable of
not screwing up their motherboard.  Well, that is not fair to those people
who know how to use a soldering iron.  So, here it is:





!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!

WARNING!  IF YOU TRY THIS ON YOUR MACHINE AND YOU SCREW UP, YOU SCREWED UP!

PROCEED AT *YOUR* RISK.  IF YOU DO NOT UNDERSTAND THESE INSTRUCTIONS THEN
YOU PROBABLY DO NOT HAVE THE REQUIRED SKILL TO DO THIS MODIFICATION WITHOUT
DESTROYING YOUR COMPUTER.  IF *YOU* KILL *YOUR* COMPUTER BECAUSE YOU DID
ANYTHING TO IT THAT I MAY OR MAY NOT HAVE EVER SUGGESTED MIGHT BE A NICE
THING TO DO (LIKE THIS UPGRADE) THEN *YOU* SCREWED UP *YOUR* COMPUTER AND
I AM IN NO WAY NOW OR EVER IN THE FUTURE RESPONSIBLE OR EVEN TERRIBLY SORRY.

!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!*!

I think that about says it.  *I* did this to *MY* computer last summer and
it has been working fine ever since.  What you do to your computer is your
business, and your responsibility.

Do not write or call looking for the PAL required for this.  I do not have
any PALs and no longer have access to producing them.  There are people out
there who read this group who can burn PALs.  Anyone want to come forward?
There are also people who have a better code for the PAL.  Maybe they will
post it, maybe not.

If anyone notices any typos, PLEASE speak up.

enough talk, here it is. Cheers!

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P5.1 Upgrade Rework Instructions:

For a P3 CPU board:

	First cut 18A pin 1 loose from the PCA and install a short
	jumper across the top of 18A to pin 20.

	Proceed with the P4 or P5 instructions.

For a P4 or P5 CPU board:
(a P4 or P5 board will not have an IC at location 18A)

	Install a preprogrammed 16R4 PAL (see listing) at 27P

	Install a 0.01 uf cap above pins 1 and 20 of 27P

	Install the following 9 jumpers (26 - 30 AWG wire)

		From 27P pin  1 to 27P pin 12

		From 27P pin  2 to 26G pin 10

		From 27P pin  4 to 27P pin 19

		From 27P pin  8 to 27G pin 13

		From 27P pin  9 to 21M pin  2

	*	From 27P pin  4 to 22H pin  7

	*	From 27P pin  7 to 22H pin 11

		From 27P pin 11 to 27P pin 10

		From 27P pin 17 to JH1-2

	Boot release 3.5 diagnostics or later and you can now format
	a drive with greater than 8 heads.  A Seagate ST-4096 formats
	to about 75 MB, for instance.

*	These two jumpers can be done to 2 feedthroughs that are not
	labeled on the motherboard but closer to 27P than 22H.
	I have some grude photocopys of the motherboard showing where 
	all of these jumpers go.  If you really want to do this
	modification to your system and you would feel better if you
	had these photocopys, send me a self addressed, stamped envelope
	along with a picture or two of George Washington (preferrably on
	$1 bill(s), or the equivalent in US stamps) to cover my time and
	six pages through the copy machine.

I have checked my typing on the PAL equations several times.  Those of you
who know, PLEASE check me for typos.  My photocopy is not very good.

PAL Equations:

PAL16R4A
S4 P5.1
CONVERGENT TECHNOLOGIES 4/9/86

CLK /PHSTAT NC DID NC NC DHDSEL /MCRSEL /RST GND
/OE /SPCLK /AA IDB NC NC /HDSEL3 /BB D4 VCC
IF(PHSTAT) /D4 = /IDB
/IDB := /DID
IF(VCC) AA = /RST
IF(VCC) BB = AA
HDSEL3 := BB* DHDSEL
IF(VCC) SPCLK = RST + MCRSEL

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Once again:

ANYTHING *YOU* DO TO *YOUR* COMPUTER, *YOU* DO AT *YOUR* RISK.

SOMEONE PLEASE CHECK ME FOR TYPOS.

Jan Isley, follower of Zen, picker of nit
jan at bagend | gatech!bagend!jan | (404) 434-1335