29 JUNE 2004

NEW ZEALAND GAZETTE, No. 79

1917

Detection of Corrupted Memory

1.15.6

A validity check of the entire contents of gaming machine Critical Memory must be undertaken at least after every restart of the device, transaction of significance (e.g. banknote input, logic door closed, large win, jackpot win, door closed, parameter change or reconfiguration) and before and after a game play. After a device restart (e.g. power off and on), the device must complete its validity check of the Critical Memory area and then perform a comparison check of all good logical copies of critical memory.

1.15.7

Any failure of a validity check is to be considered either a:
a) Recoverable Memory Corruption (optional) if at least one copy of Critical Memory is established to be good, or
b) Unrecoverable Memory Corruption.

Recoverable Memory Corruption and Critical Memory Recovery (optional)

1.15.8

If validity checking of Critical Memory information fails, and data memory remains operational, the software may recover critical memory information in order to continue game play. This option has the following implications:
a) All logical copies of Critical Memory must be re-created using the good logical Critical Memory(s) as a source.
b) The device must verify that the re-creation of the Critical Memory was successful to attempt to identify a permanent physical memory failure. If such is determined the device should enter the Unrecoverable Memory Corruption sequence.

Unrecoverable Critical Memory

1.15.9

An unrecoverable memory corruption must result in a RAM error.

1.15.10 The RAM must not be cleared automatically, and must require a full RAM clear.

1.15.11 If the gaming machine is so designed that after an unrecoverable memory corruption it is possible to view all logical copies of meters, including the customer’s credit meter, the gaming machine must highlight which of these figures are expected to be good as opposed to those that may be corrupted.

Data Partitioning

1.15.12 Gaming machine software should be designed so that machine specific information (e.g. machine address or other configurable parameters) are not stored within the same device (EPROM- or file for disk machines) as game and system software. This will provide for common game and system software devices between like machines “when performing signature calculations”.

Non-critical RAM

1.15.13 All other RAM must be checked for corruption at each power up.

Program Execution from Secondary Storage Media

1.15.14 Program execution from the approved primary storage media (EPROM, FLASH etc) is preferred. However, if program execution occurs from secondary storage media (eg. RAM), then the following conditions will apply:
a) When the program is loaded from the primary media to the secondary media, verification must take place at the end of loading. If the secondary media image is invalid, then an appropriate error message must be displayed and the image either re-created, or execution halted;
b) Once loaded, the secondary media image must be continuously verified against the contents of the primary storage media. Each verification must commence within 2 minutes of the completion of the previous verification and a verification must be completed at least once in every hour;
c) The verification procedure must use secure techniques such as CRC's or similar;
d) If the verification procedure detects an error, the EGM will enter an unrecoverable RAM error requiring a full RAM clear;
e) On each processor restart, the program contents of the secondary storage media must either be re-created or re-verified.