Alpha-Top Green753
The Alpha-Top Green753 is a 3-Spindle Pentium 1-based generic/ODM laptop released in 1996. Among ODM laptops, the Green753 is probably in the top 5 in number of brands that sold them (especially if you include the Green753+). Here's a list:
- Maxtech Yesbook X-753
- Jetta Jetbook 6300CD
- Ergo CD PowerBrick II
- Trogon
- Cyberstar
- HyperData
- ARM Computer
- CMO Gold Series
- Packard Bell
- Comtrade
- Rover/Roverbook
- Medion Computer
CPU Support
The G753 uses standard Socket 7 CPUs. It supports as slow as a Pentium 75 and as fast as a Pentium 200, although 200MHz Pentiums will report improperly as 166MHz in BIOS. They will still run at the proper speed. The G753 DOES NOT support any MMX or AMD CPUs. I've heard that these will start up with MMX chips, but the MMX functionality won't work and they won't report properly. They will not POST with AMD CPUs installed.
RAM Support
The G753 has two 72-pin slots that support up to 40MB FPM RAM. EDO RAM will not work. 84-pin FPM memory will work properly if the RAM sticks or sockets are modified so they will fit.
PSU
The G753 uses a proprietary 4-pin power supply. The proper shipping supply is made by Asian Power Devices Inc., model APD-9510-19A. Images of this supply are below in the gallery section. It appears to use the extra pins for battery charge, which was fairly common in the early 90s, but not by 1996. If you don't care about battery charge, you can probably use a standard 19V supply, but there's no source for the plug anymore so you'll have to find your own way around that issue.
HDD Adapter
Avoid buying a Green753 that doesn't come with the HDD caddy and adapter. Like most laptops, while the HDD itself is IDE, it plugs in through a proprietary interposer/adapter that's specific to this laptop and maybe the Green753+. If it doesn't come with the adapter, you won't be able to plug in a hard drive.
Specifications
| Spec | Details |
|---|---|
| CPU | Socket 7 - Intel Pentium @75, 90, 100, 120, 133, 150, 166, or 200MHz supported - MMX not supported - 200MHz does not report properly in BIOS |
| Chipset | Unknown |
| RAM | 2x 72-pin FPM slots - 8MB soldered - 40MB maximum |
| Hard Disk | - 2.5" IDE - 8GB BIOS Limit - Uses proprietary adapter board |
| Display Options | - 11.3" Passive Matrix Color @800x600 - 11.3" Active Matrix Color @800x600 - 12.1" Passive Matrix Color @800x600 - 12.1" Active Matrix Color @800x600 |
| Graphics Chipset | Cirrus Logic GD7543 - 1 or 2MB VRAM - 1MB units can be upgraded to 2MB |
| Audio | ESS AudioDrive 1788 - Stereo Speakers - Microphone |
| Main Battery | NiMH smart battery w/ BMS |
| CMOS Battery | VARTA 3-cell NiMH (Soldered, below CPU) |
| Power Supply | 4-pin proprietary - Asian Power Devices APD-9510-19A or ILAN F1560 - PSUs listed above also shipped with barrel jacks, with the SAME part numbers. Check the connector if ordering one! |
| Disk Drives | 3-spindle - 3.5" 1.44MB Floppy Drive - CD-ROM (TEAC) |
| PC Cards | 2x PCMCIA Slots - 1 slot supports ZoomVideo |
| Networking | None internal |
| Other I/O | - 1x Parallel - 1x Serial - 1x VGA Out - 1x MIDI/Game Port - 1x PS/2 - 1x Dock Connector - 1x Composite Out - 1x Mic In - 1x Line In - 1x Line Out - Infrared |
| BIOS | Phoenix |
| Pointing Device | Trackpad (Alps) |
Jumper Configs
Sourced from orphanlaptops.com
Block 1 (SW1) - CPU Speed
| Speed (MHz) | 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 |
| Also 150(?) | OFF | ON | ON | ON |
| 166 | ON | ON | ON | ON |
| 200 | ON | ON | ON | OFF |
Block 2 (SW2) - Unknown
The following settings are correct for all Green753s. I'm not sure what this one was actually for, but don't mess with it.
| SW2-1 | SW2-2 | SW2-3 | SW2-4 | SW2-5 | SW2-6 | SW2-7 | SW2-8 |
|---|---|---|---|---|---|---|---|
| ON | ON | ON | ON | ON | ON | OFF | OFF |
Block 3 (SW3) - CPU Core Voltage
| Voltage | SW3-1 | SW3-2 | SW3-3 | SW3-4 |
|---|---|---|---|---|
| 2.9v | ON | ON | OFF | OFF |
| 3.1v | ON | OFF | OFF | OFF |
| 3.3v | OFF | OFF | ON | OFF |
Resources
 Drivers |
|---|
Common Faults & Maintenance
CMOS Battery Leaks
The Green753's CMOS battery is a 3-cell VARTA NiMH pack that is soldered directly to the motherboard. It is located smack in the middle, directly below the CPU socket. These batteries are highly prone to leaking in age, and should be removed in any Green753 to prevent damage. The leads are long enough that clipping the battery out is pretty easy.
CMOS Battery somewhat required
The Green753 will act up a bit with a dead or missing CMOS battery. Without one, it will not turn on the internal display on cold boots. A Green753 in this state will still POST beep. Sometimes you will be able to get the internal display to start via waiting for the beep, pressing F2 to enter the BIOS, hitting enter so it sets default settings, then force rebooting it. If this doesn't work, you will need to connect it to an external display, do the same thing, then the internal display should start. If you want to avoid having to do this, install a new CMOS battery.
Brittle Plastic
Like nearly ever 90s laptop, the plastic on the Green753 is quite brittle with age. If the hinges are used, the plastic housing will crack and break around the display hinge mounts at the LCD. To avoid this happening, remove the hinge covers (they just slide off), and loosen the nut on each hinge to the point where the hinges can just barely hold the display up. This will put the least amount of stress on the plastics while still preserving functionality. If you do have cracks, epoxy can be used to fix them. The LCD lid latch and hinge covers are also prone to falling off, and many examples in the wild will have these parts missing. If you have one, handle it with care.
Speaker Problems
The speakers in these sound so utterly awful that I refuse to believe that they were that bad when new. My guess is that they all degrade with time. Using headphones will work, but the audio output is a bit finicky out of the jack. It has a bit of a background hum, but otherwise does sound alright. The main issue is that the volume adjustment is "jumpy". It will have a gradual change, then suddenly JUMP to be way louder from one increase level. Once you get it set at a good volume, it's fine. The speakers are an uncommon size and spec, so I haven't found an exact replacement yet. In the future I plan to try fitting similar ones in to see if they produce a good output. I've heard some people say their speakers were still fine, so I'd assume Alpha-Top used speakers from multiple vendors (this was the case in the Green751), and only one vendor's speakers go bad.
Gallery
These photos were taken of my unit, which was purchased New-Old-Stock as an unconfigured generic unit. These photos were taken right after installing a CPU, RAM, HDD, and getting Windows set up. A rare look at a pristine unit.
Click on a photo to view the full-size version.
Page last updated (MM/DD/YYYY): 10/06/2024
Update Reason: photo updates
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