Overview
 Hardware
 Software

 transAM
 Maxxtrem

"PIOS ONE" - The Creative Concept

After the prototype stadium, it will be sold in two variants of slightly differing configuration, named transAM and Maxxtrem.

The hardware impresses by its modular concept, which drives the performance to new heights thanks to newest RISC technology. But it still allows for a priceworthy entry level, so that everyone can join the PowerPC world without being excluded from being able to upgrade to workstation niveau. And later it allows for easy and efficient upgrade to new generations of processors or to configurations with multiple processors.

Design

The CPU Module is plugged on the motherboard, and it contains besides the CPU chip also the system RAM (in standard DIMM sockets) and cache RAM (optional) as well as the control circuitry for all this and the PCI bus. The PCI bus is the main interface between motherboard and CPU module. By this local arrangement of CPU and RAM, maximum performance is assured also with faster CPUs. Generally, the RAM can always be accessed at maximum speed - as fast as CPU, the control chip, and the RAM parts allow it - because there's no dependancy on other system components. This way the computing performance of the complete system can be increased theoretically and practically unlimited just by upgrading the CPU Module. Currently, CPUs of the PowerPC 603 family are used, they can be shipped with clock frequencies of currently 133 to 200 MHz. In the future, also CPU modules with more CPUs for multiprocessor operation, with other CPUs from the PPC family (like the PPC 604 or in future the "G3/Arthur" or perhaps the 704) and with higher clock rates are possible.

The mechanics of the whole computer is based on the ATX standard, which features among others direct cooling of the processor (no active cooling devices mounted on the processor anymore), short cables to peripheral drives, which increases reliability and reduces cost, soft power-on for more security, enough space in the backplane for a big number of I/O connectors, and mounting of the mainboard on a sort of drawer, which makes service works easier.

We have some picture material of the "PIOS ONE" prototype available:

• an image of the motherboard (JPEG, 40K) or
  
• a functional block diagram of the whole system (GIF, 40K) or
  
• a view of the external interfaces for peripheral connectivity on the backplane (GIF, 12K).

You have questions?

A word about speed

The second important figure is the bus speed for the connection between the CPU and the system RAM. In the very first prototype, where the older control chip MPC105 was used, this speed was 33 MHz. In the current design with the MPC106, this speed has already doubled to 66 MHz, and increasings to 80 or more MHz are possible in the forseeable future.

The third figure is the clock rate of the motherboard PCI bus, where the standard rate of 33 MHz is used.

Components

Generally, RISC processors define the state of art in microprocessor technology. RISC stands for Reduced Instruction Set Computer. These processors don't offer the programmer as many commands as older CISC processors (Complex Instruction Set Computer), but thus the hardware of these processors becomes simpler, more streamlined and thus more efficient. Much more speed and thus computing performance can be achieved with RISC computing compared to a CISC processor at comparable hardware costs. Further typical characteristics of RISC processors are terms like superscalarity and pipelined architecture.

Another basic component is the Hydra chip. Hydra was designed by Apple specifically with the PowerPC Platform in mind and is manufactured by Texas Instruments. It adds some functionality to PowerPC systems (including SCSI-2 host adaptor integration, CHRP compatibility and additional serial interfaces) and is used for several control tasks on the mainboard.

Sources: [Apple] [IBM/PPC] [Motorola/PowerPC] [Texas Instruments]

All technical information subject to change.