Apple Network Server - Hardware

Hardware

The Apple Network Server's hardware was supposed to be based on a new motherboard design specific to the product. During the development of the hardware, Apple abandoned the original motherboard design for unconfirmed reasons. In order to move forward and ship the product, Apple made modifications to the Power Macintosh 9500 logic board and ROM (locking out all Mac OS calls) and ported AIX to the new hardware. Whether related to the hardware change or by coincidence, Apple also abandoned its NetWare on PowerPC development (codename: Wormhole) at this time. The general motherboard layout seems to suggest a close relationship with PowerPC-based RS/6000 systems by IBM, which also were designed to run AIX. On the other hand, many motherboard components, especially the Open Firmware boot ROM, are similar to the "Tsunami" board used in the Power Macintosh 9500 and some Macintosh clones.

The ANS 500/132 uses a PowerPC 604 CPU clocked at 132 MHz, and the ANS 700/150 has the same family CPU but clocked at 150 MHz. Both had a L1 cache of 32 kB. The ANS 700/200 features the more advanced PowerPC 604e clocked at 200 MHz, with an L1 cache of 64 kB. The L2 cache of the ANS is mounted on a SIMM, with a standard size of 512 kB for the 500 and 1 MB for the 700s. Any ANS may have the 1 MB cache card fitted. The system bus speed is 44 MHz for the 500, and 50 MHz for the 700s or any ANS to which the 200 MHz processor card had been fitted. The ANS motherboard has eight 168-pin DIMM parity RAM slots with four of them free (with a maximum amount of 512 MB of RAM specified, even though up to 1 GB is reported to work ). The ANS 500/132 shipped with 32 MB of RAM installed (4 × 8 MB 60 ns parity DIMMs manufactured by IBM) and the ANS 700/150 and the ANS 700/200 shipped with 48 MB (2 × 16 MB 60 ns + 2 × 8 MB parity DIMMs also manufactured by IBM). For all practical purposes, the maximum RAM configuration is 4 × 128 MB parity DIMMs (512 MB, total) or 8 × 64 MB parity DIMMs (also 512 MB total). The machine will not POST (i.e. will not pass the Power-On System Test) if more than 512 MB is installed. This is an absolute restriction built into the machine's ROM-DIMM. If even one RAM DIMM is non-parity, then parity checking is turned-off for all RAM, in which case 70 ns RAM DIMMs are acceptable. FPM or EDO RAM DIMMs are acceptable, in any order, as the machine treats EDO RAM DIMMs as FPM RAM DIMMs.

All Network Servers feature an internal two-channel Wide SCSI-2 controller, an external 25-pin SCSI-1 connector and a standard 1.44 MB "SuperDrive" floppy. Six free PCI slots are available for expansion - parts supported under AIX include two Ethernet cards and a SCSI RAID card. Other ports include one ADB port, two serial ports and one AAUI port. Unlike all other Apple computers of the era, the ANS uses a VGA connector for the onboard video; an adapter for Apple displays was included.

A unique aspect of the Apple Network Servers is their case: It is fully lockable, extremely accessible, features a small LCD for diagnostics, and its front has seven device slots, with a CD-ROM and one hard drive mounted in them in the standard configuration. Additional hot-swappable SCSI hard drive modules or a DAT tape streamer can be added to the free slots. Optionally, the ANS 700 also supports redundant and hot-swappable power supply units and an internal drive rack for two further fixed hard drives. The case is large and heavy, at a height of 61.5 cm, a width of 41.5 cm, a depth of 45 cm and a weight of more than 40 kg. That means it is about the right width for a 19" rack, but needs at least 14 rack units in height. A third model in a smaller rackmount case without the large disk array, the Network Server 300 (codenamed "Deep Dish", as in a deep dish pizza), never got past the prototype stage. Also in development but never released were CPU cards featuring two CPUs. Power Macintosh 9500 CPU cards, which were available with dual processors, were not compatible with the ANS.

An ANS 500/132 may be upgraded to an ANS 500/200 simply by installing the 200 MHz processor accessory card. It is possible to upgrade an ANS 500 to an ANS 700 or to downgrade an ANS 700 to an ANS 500 simply by exchanging the power backpanel and PSU(s), but it is necessary to completely disassemble the base of the ANS in order to accomplish such an upgrade/downgrade. Alas, an ANS 700 has but one input power connection, even though it has dual, independent PSUs. However, an ANS 700 may be easily converted into a dual primary power configuration (independent primary power, possibly, and desirably, from different power panels, one possibly backed-up by an Uninterruptible Power Supply) by the simple expedient of removing the IEC input power connector and physically and electrically connecting two input power cordsets, one to each of the redundant PSUs. However, this modification probably invalidates the machine's UL Listing. Nevertheless, such a modification would implement a true N+1 redundancy configuration.