DeltaDon
Veteran Member
The Green 753 was sold by ARM, Brick/Egro, Trogon and Jetta -- perhaps a dozen more brands.
The last version of the factory BIOS could only reported CPU speeds only up to 166 MHz. I have installed a 200 MHz CPU and it operates correctly in the Green but the BIOS does NOT report the correct CPU speed - the CPU does run at 200 MHz per Sandra test program. No AMD CPU's will operate in the Green 753 because of the BIOS - no POST screen. I also tried a Cyrix MII and never got it to POST. Many 753's have only 1MB of video RAM, however a second 1 MB can be plugged into sockets on the bottom side of the motherboard. To fill the sockets you must completely disassemble the 753, so it's not an easy task for the faint at heart.
The 753 power adaptor has a four pin connector power supply and is rated at 22 - 18 volts - a strange rating that means that the voltage goes down as the current goes up.
The 753 uses only 72 pin Fast Page memory modules and has 8 MB of RAM on the motherboard. The maximum that memory can be expanded to is only 40 MB in the machines that I've upgraded. One of the companies that sold the 753 lists in their specifications that they supplied it with up to 72MB, so I need to see how this was possible. (Maybe with some unknown BIOS update?) The 753 has a BIOS that allows customization of boot device.
The hard drive carrier module plugs into the side of the 753 and the largest hard drive that I've installed in a 753, so far, is a 8 GB drive. Above 8GB I believe an overlay program is necessary to override the BIOS. I once heard that if a hard drive larger than 8.3 GB is installed that the CD-ROM drive will not function correctly - some BIOS or circuit problem may exist! I don't recall if I've ever proven or disproved this rumor.
While there isn't any USB ports on the Green 753 all other of the normally expected ports are there including an infrared port. The PCMCIA slots do not support Cardbus devices, but there is a Zoom video PCMCIA slot and a TV out port. The slots are 16 bit only and so your PCMCIA cards must work with 16 bit slots and not just 32 bit slots.
Motherboard Switch settings for Green 753 and always record the old switch settings before changing them - just in case!
SW1 - CPU Speed Settings
Note: It is possible to overclock any Pentium CPU by changing the SW1 settings to a higher speed setting. This may not be a stable condition and the CPU and/or motherboard may be damaged. Data may be lost or corrupted also. Proceed at your own risk when overclocking a CPU.
* The above 200 MHz setting is correct, but the BIOS does not report the 200 MHz speed - it reports the CPU running at 166 MHz with most BIOS versions
SW-2
I believe that this is correct for all 753's - don't mess with your SW2 switch settings!!!!!!
SW3 - CPU Core Voltage Settings
3.3v is the correct Vcc for most Intel non-mmx CPU's
The last version of the factory BIOS could only reported CPU speeds only up to 166 MHz. I have installed a 200 MHz CPU and it operates correctly in the Green but the BIOS does NOT report the correct CPU speed - the CPU does run at 200 MHz per Sandra test program. No AMD CPU's will operate in the Green 753 because of the BIOS - no POST screen. I also tried a Cyrix MII and never got it to POST. Many 753's have only 1MB of video RAM, however a second 1 MB can be plugged into sockets on the bottom side of the motherboard. To fill the sockets you must completely disassemble the 753, so it's not an easy task for the faint at heart.
The 753 power adaptor has a four pin connector power supply and is rated at 22 - 18 volts - a strange rating that means that the voltage goes down as the current goes up.
The 753 uses only 72 pin Fast Page memory modules and has 8 MB of RAM on the motherboard. The maximum that memory can be expanded to is only 40 MB in the machines that I've upgraded. One of the companies that sold the 753 lists in their specifications that they supplied it with up to 72MB, so I need to see how this was possible. (Maybe with some unknown BIOS update?) The 753 has a BIOS that allows customization of boot device.
The hard drive carrier module plugs into the side of the 753 and the largest hard drive that I've installed in a 753, so far, is a 8 GB drive. Above 8GB I believe an overlay program is necessary to override the BIOS. I once heard that if a hard drive larger than 8.3 GB is installed that the CD-ROM drive will not function correctly - some BIOS or circuit problem may exist! I don't recall if I've ever proven or disproved this rumor.
While there isn't any USB ports on the Green 753 all other of the normally expected ports are there including an infrared port. The PCMCIA slots do not support Cardbus devices, but there is a Zoom video PCMCIA slot and a TV out port. The slots are 16 bit only and so your PCMCIA cards must work with 16 bit slots and not just 32 bit slots.
Motherboard Switch settings for Green 753 and always record the old switch settings before changing them - just in case!
SW1 - CPU Speed Settings
Note: It is possible to overclock any Pentium CPU by changing the SW1 settings to a higher speed setting. This may not be a stable condition and the CPU and/or motherboard may be damaged. Data may be lost or corrupted also. Proceed at your own risk when overclocking a CPU.
| Speed | SW1-1 | SW1-2 | SW1-3 | SW1-4 |
| 75 | OFF | OFF | OFF | OFF |
| 90 | OFF | ON | OFF | OFF |
| 100 | ON | ON | OFF | OFF |
| 120 | OFF | ON | OFF | ON |
| 133 | ON | ON | OFF | ON |
| 150 | OFF | OFF | ON | OFF |
| 150 | OFF | ON | ON | ON |
| 166 | ON | ON | ON | ON |
| 200* | ON | ON | ON | OFF |
SW-2
| SW2-1 | SW2-2 | SW2-3 | SW2-4 | SW2-5 | SW2-6 | SW2-7 | SW2-8 |
| ON | ON | ON | ON | ON | ON | OFF | OFF |
SW3 - CPU Core Voltage Settings
| Voltage | SW3-1 | SW3-2 | SW3-3 | SW3-4 |
| 2.9 | ON | ON | OFF | OFF |
| 3.1 | ON | OFF | OFF | OFF |
| 3.3 | OFF | OFF | ON | OFF |
