About
ATOMIC is the most comprehensive RAM testing program ever created for the Macintosh.Whether you are an experienced professional working on multiple computers a day, or an average user looking to troubleshoot a specific issue, ATOMIC was designed with you in mind.
With just a single click, ATOMIC performs a thorough check of your system's memory.You don't even need to read the manual.More advanced testing options are available for those who wish to delve deeper into potential problems.
Malfunctioning software, a faulty hard drive, or various other peripheral issues can often be resolved with a bit of simple detective work.
The "spinning beach ball" cursor that never goes away.Strangely colored pixels that appear at random, or normal pixels that inexplicably vanish.Even random, unprovoked system restarts that result in the loss of all unsaved work—these issues are often the result of faulty memory.RAM is one of the few computer components that is frequently handled by users, sold in bulk at rock-bottom prices, and in such high demand that many manufacturers do not test their modules as rigorously as they should.A truly defective memory module will often reveal its flaws immediately after installation... That is why Micromat developed ATOMIC—the most advanced memory tester available for the Macintosh.
Testing Algorithms:
Stuck Address — During the first pass, this test writes the address of each memory cell into that very cell.On the second pass, the address is read back and verified to ensure the integrity and uniqueness of the address space.
Checkerboard — This test performs four passes.The first pass writes a specific pattern (which varies with each test run).The second pass reads and verifies that pattern, then writes the inverted version of the original pattern; this process is repeated for the remaining two passes.This test checks for "neighbor-bit sensitivity"—a condition in which changes made to one memory address inadvertently affect adjacent addresses.Extended March C — This test employs a complex algorithm consisting of six passes through memory.It traverses memory in an upward direction during the first three passes, writing and then reading/verifying either a 0 or a 1. The subsequent two passes traverse downward, again reading/writing 1s and 0s (alternately).The final pass may proceed in either direction, verifying that the last write operation was successful.This test detects address errors, coupling errors, stuck-at faults, stuck-open faults, and transition errors.
Random Values — This test first writes a series of random numbers to memory.Then, during a second pass, the initial pattern is verified.Testing with random values can help uncover intermittent problems.This test is also useful for checking for sensitivity to neighboring patterns.When run multiple times, it can help identify temperature sensitivity.
Solid Bits — This test writes a solid bit pattern—for example, all ones—to memory.The original pattern is verified, then complemented—switched to all zeros—and verified again.This ensures that every memory address is accessible for both reading and writing.
Bit Spread — This test shifts a "101" pattern across a field of zeros.The test detects changes in adjacent cells by looking for a 1 where a 0 is expected.
Walking Ones — Starting with the bit pattern 00000001, each memory cell is written to and read back to verify the pattern.The single "1" bit is then shifted to the next address, and the test is repeated for each position.This test ensures that every bit can maintain a value opposite to that of its neighboring bits—a condition known as an intra-word coupling error.It can also detect stuck-at address errors.Walking Zeroes — The inverse of Walking Ones.The initial pattern is 11111110, with a single 0 moving through memory.Useful for detecting intra-word coupling errors and stuck-at address errors.
Bit Flip — Combines Walking Ones and Zeroes with an alternating 10101010 pattern. Each bit (whether 1 or 0) is flipped to its complement as the test traverses memory, verifying that the pattern remains intact.This test is also useful for detecting intra-word coupling errors and stuck-at address errors.
Block Sequence — This test is similar to the "Walking Ones and Zeroes" tests.It shifts an exhaustive series of patterns through a field of either 1s or 0s. In addition to detecting intra-word coupling errors, it is also useful for determining whether the RAM is susceptible to "neighborhood pattern sensitivity."