SUPRA RAM TEST INSTRUCTIONS

Included in the 'c' directory of this SupraBoot disk is the 
SupraRamTest program.  If you have the 2M memory board for your
A500 SCSI interface, a 500XP hard drive system, or a Supra memory
board for the A2000, please read on.

The SupraRamTest program will verify the performance of your new 
RAM board.  This is particularly important if you
have purchased an unpopulated board and want to test your own
chips.  Before you use the program, you must first properly 
configure the board's test jumper.  

2M MEMORY BOARD FOR A500 SCSI INTERFACE:
This jumper is labeled "JPT" on the circuit board.  With the 
jumper on the pair of pins nearest the Amiga, the RAM will 
AutoConfigure.  With the jumper on the outer set of pins 
(closest to the RAM chips), the RAM can be tested.

A500XP:
Locate DIP switch #5, which is used to switch the RAM between
Test Mode and Run Mode.  Push Dip switch #5 DOWN (putting the
RAM in Test Mode).

A2000 MEMORY BOARD:
Locate the three-pronged header marked T R in the center of the
RAM board.  Move the jumper to the T position.


Once the test jumper has been set to the test position, boot
your system.  Open a CLI window and with the SupraRam disk in
DF0: enter the following command:

	DF0:c/SupraRamTest

The SupraRamTest will load and check for a valid RAM module to
test.  If a RAM module is found that has it's jumper in the test
position, the SupraRamTest program will inform you of the fact.
NOTE: The SupraRamTest tests the memory in 4M chunks.  If you have
more than 4M and want to test the upper bank, hit N.  The program
will then ask you if you want to test the upper 4M bank, hit Y.

The actual testing of the RAM is started by pressing the RETURN
key.  Press the Ctrl-C key combination to stop testing.  Each
complete pass of the test program takes approximately five
minutes to complete.  If the test detects an error, the bad
bit is returned to help trace the problem.  

NOTE:  All Supra RAM module boards are extensively tested before
they are shipped.  If you have ordered a zero kilobyte board for
use with your own memory chips and experience problems, it is 
likely that you have one or more bad memory chips.

TROUBLESHOOTING:  Make sure that no pins have been bent under
a RAM chip.  As simple as this sounds, this is the number one 
cause of problems.  Next, try switching the location of one pair of
RAM chips at a time and re-running the SupraRamTest program.  
This can help localize the faulty chip because when the bad chip
is moved to a new position, the error message changes.

If the ram test program displays an error message, it will indicate
which chip of the bank of memory is bad.  The error message will be:

BAD BIT 3 AT ADDRESS 20xxx

The bad bit will indicate which chip is bad, the first 2 numbers
of the address will indicate which bank of memory is bad.


		2M MEMORY BOARD IN A500 SCSI INTERFACE

The address will be 20-3F.  The chips are numbered from U10 to U1F.
The bad bit will correspond with the last part of the chip id.
IE. If the message says BAD DATA BIT 4 AT ADDRESS 20E33.  The bad
bit is 4 so the bad chip is U14. 


			A500XP 

TABLE 1:
256x4	1Mx4	Bank
--------------------
20-27	20-3F	1
28-2F	40-5F	2
30-37	60-7F	3
38-3F	80-9F	4

TABLE 2:
Bank	  |	1	2	3	4
----------|-----------------------------------
bit 0-3	  |	U1	U5	U9	U13
bit 4-7   |	U2	U6	U10	U14
bit 8-11  |	U3	U7	U11	U15
bit 12-15 |	U4	U8	U12	U16

Using TABLE 1, find the address range under the column heading
of the type of memory chips used.  Read accross to find the 
Bank number.  Look at TABLE 2, use the Bank column and find the
bit row.  Where the 2 cross will give you the chip that is bad.
IE. Using 256x4 chips, error message says BAD DATA BIT 9 AT 
ADDRESS 335ED.  Table 1 gives us Bank 3.  Where the row BIT 8-11
meets the colume 3 is the chip, which is U11.


		A2000 MEMORY BOARD

1st bank of memory is address 20-3F chips U10-U1F
2nd bank of memory is address 40-5F chips U20-U2F
3rd bank of memory is address 60-7F chips U30-U3F
4th bank of memory is address 80-9F chips U40-U4F

Using the above table find the correct row with the bad chip.
The bad bit will correspond with the last part of the chip id.
IE. If the message says BAD DATA BIT 7 AT ADDRESS 40E33, first
find that the error is in the 2nd bank.  The bad bit is 7 so the
bad chip is U27.

26 October 1990