User manual AOPEN AP5T-HW

[. . . ] It may cause your system unstable if you can not meet the heat dissipation requirement from above CPU type. It is recommended to adopt larger fan on these CPU for better air flow in the system. Please refer to AOpen 's web site (http://www. aopen. com. tw) to choose a proper CPU fan. Tip: Normally, for single voltage CPU, Vcpuio (CPU I/O Voltage) is equal to Vcore, but for CPU that needs dual voltage such as PP/MT (P55C) or Cyrix 6x86L, Vcpuio is different from Vcore and must be set to Vio (PBSRAM and Chipset Voltage). [. . . ] The view angle of drawing shown here is from back panel of the housing. Note: The mini DIN PS/2 keyboard connector is optional. PCB KB1 2-19 Hardware Installation 2. 3. 12 IrDA Connector Serial port 2 can be configured to support wireless infrared module, with this module and application software such as Laplink, user can transfer files to or from laptops, notebooks, PDA and printers. This mainboard supports IrDA (115Kbps, 1 meter) as well as ASK-IR (19. 2Kbps). Install infrared module onto IrDA connector and enable infrared function from BIOS setup, make sure to have correct orientation when you plug onto IrDA connector. Pin 1 2 3 4 5 6 Description +5V NC IRRX GND IRTX +3. 3V Note: Onboard serial port 2 (COM2) will not be available after IrDA connector is enabled. 1 2 3 4 5 6 IrDA 2-20 Hardware Installation 2. 4 Configuring the System Memory Pin 1 of DIMM2 Pin 1 of DIMM1 This mainboard has four 72 pin SIMM sockets (Single-in-line Memory Module) and two 168 pin DIMM socket (Dual-in-line Memory Module) that allow you to install system memory from minimum 8MB up to maximum 256MB. Pin 1 of Bank1 Pin 1 of Bank0 The SIMM supported by this mainboard can be identified by 4 kinds of factors: Size: single side, 1Mx32 (4MB), 4Mx32 (16MB), 16Mx32 (64MB), and double side, 1Mx32x2 (8MB), 4Mx32x2 (32MB), 16Mx32x2 (128MB). Speed: 60ns or 70ns access time Type: FPM (Fast page mode) or EDO (Extended data output) Parity: without parity (32 bit wide) or with parity (36 bit wide). The DIMM supported by this motherboard are always 64-bit wide SDRAM, which can be identified by following factors: I. Size: single side, 1Mx64 (8MB), 2Mx64 (16MB), 4Mx64 (32MB), 8Mx64 (64MB), 16Mx64 (128MB), and double side, 1Mx64x2 (16MB), 2Mx64x2 (32MB), 4Mx64x2 (64MB), 8Mx64x2 (128MB). Tip: Here is a trick to check if your DIMM is single-side or double-side -- if there are traces connected to golden finger pin 114 and pin 129 of the DIMM, the DIMM is probably double-side; otherwise, it is single-side. Following figure is for your reference. 168 85 Pin 129 Pin 114 2-21 Hardware Installation II. Speed: normally marked as as -12, which means the clock cycle time is 12ns and maximum clock of this SDRAM is 83MHz. Sometimes you can also find the SDRAM marked as -67, which means maximum clock is 67MHz. Buffered and non-buffered: This motherboard supports non-buffered DIMMs. You can identify non-buffered DIMMs and buffered DIMMs according to the position of the notch, following figure is for your reference: non-buffered Reserved buffered Because the positions are different, only non-buffered DIMMs can be inserted into the DIMM sockets on this motherboard. Although most of DIMMs on current market are non-buffered, we still recommand you to ask your dealer for the correct type. 2-clock and 4-clock signals: Although both of 2-clock and 4-clock signals are supported by AP5T, we strongly recommand you to choose 4-clock SDRAM in consideration of reliability. Tip: To identify 2-clock and 4-clock SDRAM, you may check if there are traces connected to golden finger pin 79 and pin 163 of the SDRAM. If there are traces, the SDRAM is probably 4-clock; Otherewise, it is 2-clock. Parity: This motherboard supports standard 64 bit wide (without parity) SDRAM. Because Pentium processor has 64 bit bus width, the four SIMM sockets are arranged in two banks of two sockets each, they are Bank0 and Bank1. It is allowed to have different speed and type in different bank, for example, 70ns FPM in one bank and 60ns EDO in another bank, in such case, each bank is independently optimized for maximum performance. The memory timing requires at least 70ns fast page mode DRAM chip, but for optimum performance, 60ns EDO DRAM is recommended. Warning: The default memory timing setting is 60ns to obtain the optimal performance. Because of the specification limitation, 70ns SIMM is recommended to be used only for CPU external clock 60MHz. [. . . ] Note that 64MB SIMMs using 16M by 1 bit chip (16M bit technology) have chip count exceed 24 and are strongly not recommended. Tip: 8 bit = 1 byte, 32 bit = 4 byte. The SIMM size is represented by number of data byte (whether with or without parity), for example, the size of single side SIMM 2-27 Hardware Installation using 1M by 4 bit chip is 1Mx32 bit, that is, 1M x 4 byte= 4MB. For double side SIMM, simply multiply it by 2, that is, 8MB. Following table are possible DRAM combinations that is NOT recommended: SIMM Data chip 1M by 1 1M by 1 1M by 4 4M by 1 4M by 1 16M by 1 16M by 1 SIMM Parity chip None 1M by 1 1M by 1 None 4M by 1 None 16M by 1 Bit size per side 1Mx32 1Mx36 1Mx36 4Mx32 4Mx36 16Mx32 16Mx36 Single/ Double side x1 x1 x2 x1 x1 x1 x1 Chip count 32 36 24 32 36 32 36 SIMM size 4MB 4MB 8MB 16MB 16MB 64MB 64MB Recommended No No No No No No No DIMM Data chip 4M by 4 4M by 4 16M by 4 16M by 4 Bit size per side 4Mx64 4Mx64 16Mx64 16Mx64 Single/ Double side x1 x2 x1 x2 Chip count 16 32 16 32 DIMM size 32MB 64MB 128MB 256MB Recommended No No No No Memory error checking is supported by parity check. To use parity check you need 36 bit SIMM (32 bit data + 4 bit parity), which are automatically detected by BIOS. [. . . ]