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Lenovo Thinkpad T420 (Bobopeep)

Bobopeep Front
ArcaOS license type


The Lenovo Thinkpad T420 is a full sized laptop that has a powerful CPU, graphics and a DVD Writer. The VGA adapter is suited to an external monitor. The 14.1 inch screen has a screen resolution of 1366 x 768, also known as FWXGA.


After you add the computer and optional CPU upgrade to the cart, proceed to the Accessories page to add a hard drive upgrade, a USB floppy drive or a travel router.


Hard drive upgrade

The hard drive can be upgraded to a 2 TB drive. Either a hard disk or an SSD is available to upgrade.

Hard drive upgrade

Bobopeep hard drive upgrade
Storage type

USB Floppy Drive

An external USB Floppy drive can be used to read and write 720K and 1.44M 3 1/2 inch floppy disks.

USB Floppy Drive

USB Floppy Drive

USB Floppy Drive: $50.00 USD

External WiFi

I use the Mango Travel Router with this laptop to access local WiFi or my phone's hot spot. Mango comes with everything you need to connect to an access point.

Mango Travel Router

Mango Thumbnail

Mango Travel Router: $65.00 USD

In the past, I have also used a TP-Link AC750 Wireless Travel Router, an Asus RP-N12 Wireless N300 Range Extender, and a TP-Link Nano Router. I include a folder of URL links to the admin pages of each of these routers to make it easy to set up the first time.

Instructions and details about external WiFi: Travel Routers

Custom Orders

If you want to buy a customized version of this computer, fill out an order form and submit it to Blonde Guy. Blonde Guy will review your order and send you an invoice, payable using PayPal or any major credit card. If you prefer to pay by check, note that in the notes field of the order form, and I will e-mail you an invoice payable by check.

Enter the customizations you want on the computer in the notes portion of the order form.


Model: Thinkpad T420
Model number: 4178-6UU
Year introduced: 2011
CPU: Intel(R) Core(TM) i5-2520M CPU @ 2.50GHz
Screen: 14.1 inch Color LCD, 1366 x 768 pixels
Hard drive: 500 GB SATA
Optical drive: DVD-RW
Intel HD 3000 graphics
USB 2.0 Ports: 3

Physical Dimensions

Height: 1.1 inch
Width: 13.2 inches
Depth: 9.4 inches
Weight: 4.5 lbs

Power Consumption

Power consumption is 43 Watts, measured with the computer booted to the desktop. This computer consumes 1 Watt if it's plugged in, but switched off.


The built-in webcam can be used with WebSee software. WebSee now works with the supplied USB 12.x from Arca Noae.

RAM drive

The laptop can use any memory left over from 32-bit usage as a RAM drive. For the 6 GB RAM model, this RAM drive has 2.5 GB, and is formatted HPFS.


This laptop boots to the desktop in under 60 seconds. That's important, because suspend/resume does not work. To make up for that, the laptop can do a clean power down when the lid is closed.

There is no ArcaOS support for the bluetooth. DOS Window does not function, but DOS Full Screen does. Pressing Alt-Home on the DOS Full Screen session converts it to a working DOS Window.

Disk Layout

The disk is partitioned to provide a bootable operating system volume and a bootable installer. Space is left for addtional bootable volumes. User data is stored on a separate volume.

This is the layout for a 500 GB HD. A bit of free space has been left to make operating system upgrades easier.

Volume NameDisk FormatDrive LetterVolume SizeDisk Name
ArcaOS-HJFS H:10,001 MB500 GB SATA
Data JFS D:436,939 MB500 GB SATA

ArcaOS version

ArcaOS 5.0.7 (Dec 7, 2021) is the version used for this installation.

Performance Benchmarks

This table reports the SysBench 0.9.5 benchmarks for this computer. You can download SysBench 0.9.5 here:

PM-Graphics-marks 152
CPU integer-marks 9725
CPU floating point-marks 527
DIVE-marks 5962
File I/O-marks 47568
Memory-marks 8113
Simultaneous I/O-marks 85
Disk I/O-marks 338


Preloaded Software

Each Blonde Guy ArcaOS preloaded computer comes with a standard load of software. This page lists what is in the current pre-load. This list is updated over time to incorporate new essential OS/2 software as well as to keep up to date versions of existing software. When you receive your ArcaOS preloaded computer, you will have Blonde Guy's best installation of the latest OS/2 software.

Recovery DVD

The recovery DVD supplied is a bootable ArcaOS DVD with a backup of the hard drive as delivered. You can boot the machine from DVD, and perform maintenance functions. The maintenance folder is available on the recovery DVD. The factory backup is stored in the \Factory directory. The backups are simple zip files. You can use 7z or unzip to extract some or all of the files in a backup.

Build Notes

This laptop computer is configured to boot ArcaOS.

This section documents what I did to get this computer to work under ArcaOS. It is intended to show what goes into this computer, and also as a guide to the user who wants to build it himself.

BIOS changes

BIOS update

I made sure the BIOS was updated to the latest version. This may not be necessary, but I did it anyway. The current BIOS revision is 1.52 released on 4 Jun 2018. Firmware is version 1.20. I updated the BIOS to the current level with the BIOS update CD downloaded from the Lenovo support website.

BIOS settings

I made the following changes to the default BIOS settings. Then I powered the Thinkpad down and up.

Hard drive preparation

I had a 320 GB hard drive and installed it according to instructions in the Lenovo Hardware Maintenance Manual. The drive had previously been used and has Windows 10 installed on a partition created by ArcaOS. be prepared using the ArcaOS installer.

ArcaOS Installation

I installed one bootable volume, H:. The H: drive has a Custom installation with Samba Server included to share files. A System Dump partition is now included.


As of ArcaOS 5.0.7, sound is working normally on the laptop. Both UniAud and USB audio are installed and working. ArcaOS now switches between UniAud and USB audio automatically when a USB audio device is attached.

DOS Support

Support for the DOS Window is defective. DOS Full-Screen works normally. Alt-Home from a DOS Full-Screen then allows a DOS Window to work. The VOIP.SYS driver is used to enable DOS Full-Screen support.

Factory image

Using Suntan Special I run sequences ArcaOS50, apps, games, dev and cleanup. This is saved as the Factory image. This is normally what would be supplied on the computer.


These are photos of the prototype Bobopeep laptop. While each laptop will differ slightly, I try to resell laptops in good condition.

Front and Right

Bobopeep Front and Left


Bobopeep Right


Bobopeep Left


Bobopeep Rear


Bobopeep Keyboard