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Q.  Can SIMCHECK or SIMCHECK PLUS support the new 
SDRAM DIMM modules?

A.  NO, SIMCHECK or SIMCHECK PLUS were developed long before the 
emergence of the new SDRAM DIMMs and they lack the computational power
and 1nS technology to support SDRAM.  SIMCHECK PLUS is our entry level
memory tester for testing standard DRAM only.  Customers who wish
to test SDRAM DIMMs should use our RAMCHECK or SIMCHECK II Plus units.

Q.  How long does it take SIMCHECK to test a SIMM module?

A.  It depends on the size and quality of the module, and which tests
are performed.

SIMCHECK's setup can be modified to skip certain Extensive test phases, 
which shorten the overall test time.  Higher quality modules with higher
refresh rates will take longer to test than lower quality chips.
Module Test Times
Size BASIC EXTENSIVE (all tests)
1 MB (256Kx36) 10 sec. 1.5 - 2.0 min.
4 MB (1Mx36) 15 sec. 2.0 - 3.0 min.
16MB (4Mx36) 30 sec. 8.0 - 10.0 min.

Q.  What are the benefits of the new EPROM versions?

A.  Version changes may include support for new modules that may
have not been supported previously or support for adapters that have 
recently been released.  Please refer to the SIMCHECK Development Log 
for a detailed explanation of each version.

Q.  Can SIMCHECK or SIMCHECK PLUS support EDO modules?

A.  Yes, SIMCHECK's program version 2.34 and above readily identify EDO

Q.  Why does the red LED turn on before I start the test?

A.  Because the module has a small voltage leak (4-7mA). If these modules
test ok otherwise, while they may be of lower quality, they are usually
ok to use in Alternating Current (AC) powered PCs.  The modules may not 
be appropriate in some laptop PCs.

Q.  What are the two binding posts at the back of SIMCHECK used for?

A.  The current of the module under test can be directly measured 
by connecting a voltmeter to these posts (red is positive).  One Volt
on your meter indicates one Amp consumed by the module under test.
NOTE: The black post is NOT grounded!  We use red and black posts only to
indicate the correct polarity for the voltmeter.

Q.  Why does SIMCHECK show my x9 SIMMS as x8?

A.  This may happen on the PS/2 model-30 adapter, because of the module 

  1.  It may be a single -CAS module, and needs to be tested with the 
Single -CAS Adapter.

  2.  It may be a logic parity module, also supported on the Single -CAS 

  3.  It may have a defective 9th bit, and therefore can only work as a x8.

Q.  Why do modules test good on the SIMCHECK, but fail in a PC?

A.  The PC may require true parity 9-bit SIMMS, and the tested
module is a 8-bit SIMM that uses logic parity.  

Simcheck may not explicitly fail a chip, but an interpretation of
the readings may indicate a suspect or bad chip.

Q.  What are Soft Errors?

A.  Soft errors in memory products are those transient errors which 
appear randomly, and cannot be verified.  They may stem from alpha particle
radiation or other faults in the memory.  When SIMCHECK encounters an 
error, it immediately tries to verify  it.  If the error is not repeated,
the soft error counter is incremented.  Soft errors are more common in 
larger or more complex memory products.

ELIMINATING SOFT ERRORS:  In some rare instances, the soft error may be an 
artifact of the automatic access time algorithm.  This occurs when the 
actual speed of the tested device is just a hair below SIMCHECK's access 
time measurement slots, causing some memory accesses to result in inter-
mittent errors.  While the access time measurement algorithm will 
eventually drift to slow the access time, soft errors may still register.  
To eliminate this artifact, simply run the test again at a setup speed  
which is a notch slower than the automatically measured access time.
For example, if a module tests at 55nS with an abnormally high soft 
error count, retest it with a speed of @60nS or even @70nS (using Speed 
Override or Speed Setup -see Section 4.1 in your SIMCHECK MANUAL).

Q.  Why do modules work in a PC, but fail on SIMCHECK?

A.  The modules may have a violation in timing or JEDEC standards, so that
the SIMCHECK will fail it, but it will work in some PCs.

The modules may be of a new type or configuration that SIMCHECK or its 
current EPROM doesn't support.

Q.  How can I build my own customized adapters?

A.  A wiring diagram for SIMCHECK's 50 pin expansion slot is
in Appendix I in the manual. If the customer knows how his custom module
is wired, he may be able to construct his own adapter. For a custom adapter
for 72-p modules, you may purchase the CUSTOMIZED ADAPTER for the

Q.  What about intermittent errors in the fast page mode test?

A.  If a chip sometimes passes, then sometimes fails the fast page mode 
test, then most likely, the fast page mode function of the module is 

Q.  Why is there a 10ns speed difference between the two SIMCHECKs I have?

A.  The speed determination in SIMCHECK is +/- 5ns, if one SIMCHECK is 5ns
high, and one is 5ns low, the difference would be 10ns, this is normal.

Q.  How can I calibrate my SIMCHECK?

A.  The SIMCHECK is designed not to require periodic calibration.
But, EPROM upgrades are recommended.

To meet ISO 9000 requirements, we have established a calibration
verification routine. Please contact us for more details.

Q.  Why is the latest adapter I just received, not working with 

A.  Check for dirt, corrosion, foreign objects stuck in the SIP (green)
socket.  A simple tech spray solution applied to the adapter's pins will
usually eliminate problems that are due to a bad contact or connection.

  2.  Try reinserting the adapter a few times.

  3.  The EPROM version may not support the adapter.  Verify that the
program version (seen on power up) supports the adapter you are trying 
to use.  Refer to the SIMCHECK Development Log.

Q.  Can the SIMCHECK test Logic Parity or Parity Emulation memory modules?

A.  Yes.  The 30 pin modules using logic parity are identified if tested
with the Single -CAS Adapter.  The 72 pin modules are identified when 
tested with the 40-Bit Port.


Q.  Can I use the power supply from the SIMCHECK to power the 40-BIT PORT?

A.  No.  Although it is possible to do this, you SHOULD NOT because 
SIMCHECK's power source cannot supply the amount of current needed by large 
72-pin modules.  Performing a test with this setup may hang the SIMCHECK
program. For proper use, SIMCHECK's power supply should be disconnected
from the power outlet, and the 40-BIT PORT power supply should be
connected at the auxillary power connector.  UNDER NO CIRCUMSTANCE
should both power supplies be connected at once, this will cause one,
if not both, to be damaged.

Additional Note:  Most SIMCHECK units of today have a detachable power 
supply.  In cases like these, you may remove the SIMCHECK power source
permanently and use the 40-BIT PORT power source in its place.  

Q.  Why do I get inaccurate test results when testing 30 pin 
modules on my SIMCHECK PLUS?

A.  You must disconnect the 40-BIT PORT from the SIMCHECK, and use 
SIMCHECK's power supply when testing 30 pin modules.  You cannot test 
30 pin modules accurately when the 40-BIT PORT is connected to SIMCHECK.

Q.  Why must I disconnect the 40-BIT PORT, when testing 30
pin modules?

A.  The 40-BIT PORT is connected to SIMCHECK's main data bus thus add 
some additional capacitive loading which may skew critical timing signals.  
We have developed a quick disconnect cable to facilitate
easy connection and removal of the 40-BIT PORT as part of the 
SIMCHECK PLUS system.  This quick connect cable will be sent 
no-charge to any user that requests one.

Q.  I just got the 40-BIT PORT, and it works ok with its power
supply, but why does the SIMCHECK power supply not work?

A.  If both the SIMCHECK power supply and the 40-BIT PORT power 
supply are plugged into electrical outlets at the same time, the SIMCHECK 
power supply may burn out.  Only one power supply can be in at one time.  
The user can send the unit in to be  repaired, or we can fax them an 
instruction sheet on how to connect the 40-BIT PORT power supply to the

Q.  Why do I get ERROR: ADDRESS IN ALL MODULE or b5 errors when 
testing x36 72-pin modules in the 40-BIT PORT, the modules work in a PC.

A.  EPROM versions 2.22 and up support the identification of 
Logic Parity or Parity Emulation modules in the 40-Bit Port.  Prior 
versions may give this error when testing these types of modules.

Q.  Does the 40-BIT PORT test for 2K and 4K refresh?

A.   Yes, in fact the testing that is done is more rigorous than that 
of the 2K and 4K standards, but both are covered.

Q.  Can SIMCHECK remember its settings once it is turned off?

A.  No.  But the settings are retained if you have the PC COMMUNICATION
device attached to the Simcheck.


Q.  Can the STATIC TESTER accept 3/10's (.3" or 300 mils) and 4/10's 
(.4" or 400 mils) static chips?

A.  Yes, the tester can accept up to 6/10's (.6" or 600 mils wide) chips.


A.  There is partial support for the STATIC TESTER on version 1.05 and 
above on the PC COMMUNICATION program.  


Q.  Does the DRAM CARD TESTER support the 68 pin PCMCIA memory cards?

A.  No, it supports the 88 pin JEIDA/JEDEC DRAM memory cards.


Q.  Can the AST adapter test the new 16MB modules?

A.  Yes, the adapter may require a hardware modification, and a new EPROM.


Q.  Why do some 256K chips give different errors at different sockets?

A.  These problems are resolved with the new style adapter (w/switches).


Q.  How fast can the Handler test modules?

A.  The Handler is rated at 1,000 modules/hr with zero test time.
This is equal to 3-4 seconds per module.  If a 1MB module takes 10
seconds to do the basic test, then it will take 13-14 seconds 
to test each module.  Larger modules will take longer.
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