Acer V12C Motherboard
Jumper and Connector Layout
Note - The blackened pin of a jumper represents pin 1.
The system board has the following major features:
- CPU: P54C-75/90/100MHZ, 3.3V
- Chipset: 82434NX, 82433NX, 82378ZB
- L2 Cache: 256KB, 3.3V SRAM
- Memory: 4 SIMM Sockets, each supports 4MB ,8MB, 16MB, 32MB SIMMS
- ROM: 128KB memory for system BIOS
- Realtime Clock: System clock/calendar with 128Bytes CMOS RAM. Over 10 Yrs. of nonvolatile operation in the absence of power
- On-Board I/O:
- 2 Serial ports (NS16550 Compliant)
- 1 Parallel port (Supports EPP,ECP)
- 1 Keyboard/PS2 Mouse Port
- FDD: Supports 2FDD'S (including 2.88MB)
- HDD: Supports 2HDDS
- Expansion: First,there is a total of 8 physical slots. Second, only 7 slots can be used sinultaneously because of the 5 ISA slots, one slot would be rendered unuseable id a PCI card is inserted into the #3 PCI slot. Conversly, even though there are 3 PCI slots, one of them would be unuseable (#3 position) if an ISA card is inserted into the ISA slot right next to the #3 PCI slot.
Note - There are three V12C CPU configurations: Pentium 75, 90, and 100. However, these are all different versions of the V12C motherboard. You cannot change the processor on a V12C.
|JP4||1-2*||Enable onboard Super I/0 SMC665|
| ||2-3||Disable onboard Super I/0 SMC665|
| ||2-3||OEM BIOS|
| ||2-3*||Disable password|
|JP8||1-2||Connect DACK3# for ECP of 5MC665|
| ||2-3||Connect DACKl# for ECP of SMC665|
|JP12||1-2||Connect DRQ3 for ECP of SMC665|
| ||2-3||Connect DRQl for ECP of SMC665|
|JP9||ON||Enable PS/2 mouse IRQ12|
| ||OFF||Disable PS/2 mouse IRQ12|
|JP18||1-2*||60 MHz speed|
| ||2-3||50 MHz speed|
|JP21||ON*||Enable P54C pipelined function|
| ||OFF||Disable P54C pipelined function|
| ||OFF||Enable keylock|
|JP24||1-2||CPU speed = 3/2 of the bus speed|
| ||2-3||CPU speed = 2 times the bus speed|
You can upgrade the system memory by adding memory modules (SIMMs) into the SIMM sockets or by changing the SIMMs for a higher memory configuration. The system supports single- and double-density SIMMs: 4-MB, 8-MB, 16-MB and 32-MB upto a maximum of 128MB. Use only 70 ns or faster NON-parity Fast Page Mode SIMMs. The system board has two DRAM banks composed of two SIMM sockets each. Memory modules must be fitted in pairs.
The V12C ships with 256k write-back second-level cache and is not upgradable.