Packard Bell 450 M/Board

450 board diagram

Specification

Jumpers

JumperFunctionSettingDescription
J8 Color/Mono selectClosed
Open
* Colour
Monochrome
J9 Video IRQ enableClosed
Open
* Enabled
Disabled
J10 Password clearClosed
Open
Clear Password
* Normal Operation
J11Onboard game port selectClosed
Open
* Enabled
Disabled
** J15 / J16ECP DMA select1-2
2-3
* DMA Channel 1
DMA Channel 2
J17 Boot Select1-2
2-3
Boot Block
* Normal
J18 Parity Enable1-2
2-3
Enabled
* Disabled
J19 Onboard VGA Enable1-2
2-3
Disabled
* Enabled
J20 Onboard I/O Controller1-2
2-3
Disabled
* Enabled
J25 CPU Speed select 1-2
2-3
25MHz
33MHz
J26 Cache size selectionOpen
1-2,
3-4
0K
128K
512K
J28 P24T or S-series reset control1-2
2-3
* P24T
S-series CPU Standard CPU
(Do Not Change to add P24)
J29 P24C Clock multiplier1-2
2-3
Open
Other Multiplier
X2 Internal clock
X3 Internal clock
J30 Onboard battery enableOpen
3-4
Use external battery
* Use internal battery
J31 SX processor selection1-2 3-4
5-6
All except (SX)
SX
J32 J(3.3v) (CPU voltage) 1-3 2-4
3-5 4-6
3.3V CPU
* 5.0V CPU
J33 LDEV bypassOpen
Closed
Disabled
Enabled
J36 Onboard speaker enableOpen
3-4
External speaker
* Internal speaker
J37 Onboard memory DisableOpen
Closed
* Enabled
Disabled

* Indicates default value.
** J15 and J16 must match

Battery

Use a 3 volt lithium battery. Remove the jumpers on pins 3-4 of the J30 (Jbte) battery connector. The battery will connect to pins 1 and 4 (pin 1= +3 volts, pin 4= ground)

Cache Upgrade

The Cache and TAG RAM are either 28-pin for 128KB of cache, or 32-pin for 512KB of cache.

 J26
NoneOpen
128kOpen
512kClosed

CPU Upgrades

Jumpers J25J29J31
CPUSpeedMultiplierSX/DX
486SX251-21-25-6
486SX332-31-25-6
486SX/2-501-22-35-6
486DX-332-31-21-2 & 3-4
486DX/2-50
486-25
486DX/4-75
P24T-62MHz
1-22-31-2 & 3-4
486DX/2-66
ODP486-33
P24T-83MHz
2-32-31-2 & 3-4
486DX/4-1002-3none1-2 & 3-4

Memory Upgrades


Speaker

Use an 8 ohm, .5 watt computer speaker. Remove the jumper on pins 3-4 of the J36 (Jspk) connector. The Speaker will connect to pins 1 and 4. (pin 1= =5 volts, pin 4=speaker ground).

Video Memory Upgrade