Installation manual

IDPROM
The IDPROM address space provides system information including Machine Type, Serial Number,
Ethernet Address, and Manufacturing Date. This information may be stored in an IDPROM,
NVRAM, or EEPROM. The 32 Bytes of IDPROM content are shown below.
BYTE FIELD SIZE
1 Format 1 Byte
2 Machine Type 1 Byte
3 Ethernet Address 6 Bytes
4 Date 4 Bytes
5 Serial Number 3 Bytes
6 Checksum 1 Byte
7 Reserved 16 Bytes
The Machine Type and Serial Number are combined to create the Hostid. Licensed software may use
the Hostid.
Prior to the SPARCstation 10, the Machine Type was used by the operating system to identify the
architecture and the architecture implementation.
Beginning with the SPARCstation 10, systems are not assigned a unique Machine Type. The device
tree in the Open Boot PROM provides the system characteristics to the operating system. The
high-order bit of the Machine Type is set to 1. The lower 7 bits of the Machine Type and Serial
Number fields are used at Sun's discretion.
The alpha-numeric code on the NVRAM barcode label can be used by Sun to create a duplicate
NVRAM. Provide this information when ordering a replacement NVRAM.
IDPROMs, NVRAMs, and EEPROMs are not interchangeable.
Programmed components that have a unique machine type are not interchangeable. For example, a
new NVRAM is required when an SS2 (55xxxxxx) is upgraded to an SS20 (72xxxxxx).
Different component types are not interchangeable between systems. For example, a new NVRAM is
required when an SS4 is upgraded (48T08) to an Ultra 1 Model 140 (48T59).
The 48T08 and 48T18 have the same pin count as the 48T59 but they are not pin compatible with the
48T59.
The NVRAM also contains a Time of Day clock. Accuracy of the clock is typically +/- 1 minute per
month at 25°C. The 32,768Hz oscillator is tested not to exceed +/- 1.53 minutes per month (35PPM)
error rate at 25°C.
Sun4/II: Parts - Board - IDPROM
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