Introduction

Coremark is a cross-platform CPU benchmark tool. I would like to create a Linux boot floppy disk that would boot on a real Intel 80386 machine and then run the coremark. It should support 80386SX with as little as ~8MB of RAM.

** WARNING **: The method described here is tested and failed to work on real machines / 86box. This project is not considered as done, and may be revisited in the future.

Buildroot

The buildroot is used to compile the gcc 5 that will be used to compile the kernel and the coremark. Linux distribution offered compiler doesn't quite work here because:

1. We are stuck with Linux 3.2.102 if 386 support is necessary. Linux 3.2 can only be built with gcc 3-5 by default.
2. The libc bundled with distribution compiler is unlikely to target i386. This cause issues when trying to link them statically into the build.

Buildroot Config

The last buildroot version that supports 386 is the 2016.02 version. Download, extract and run make menuconfig.

Set target architecture to i386, and target machine to 386. Set gcc version to 5.x. In bootloaders, select syslinux, image to install is mbr.

Buildroot Patch

There are several patches that is required to build the system correctly, apply them to the buildroot.

Introduction

TIM or Alice Mobile IDOL (Internet Device on Linux) is a MID (Mobile Internet Device) that was once produced back in 2007 - 2009 (rough time frame, not confirmed). IDOL is among one of the many OEM varients of the Compal Jax10. Most of the varients have the following spec:

• Intel Atom Z500 processor (45nm, 1C1T, 800MHz)
• Intel US15W chipset (GMA 500 Integrated Graphics)
• 512MB DDR-2 memory
• 2 x Intel Z140 2GB SSD
• Bluetooth
• AirDio AD1111 WiFi (Marvell SD8686 SDIO chip)
• 4.8" 800x480 Touchscreen
• U-blox NEO-5Q GPS
• Dual Camera (3MP AF)

The following is a (maybe incomplete) list of the models produced:

• Aigo P8860
• Aigo P8861 (8GB SSD)
• Aigo P8861H (8GB SSD, HSDPA 3G)
• Aigo P8880 (8GB SSD, HSDPA 3G)
• Aigo P8880E (8GB SSD, EVDO 3G)
• Aigo P8880T (8GB SSD, TD-SCDMA 3G)
• Aigo P8888 (EVDO 3G)
• Aigo P8888W (HSDPA 3G)
• Aigo P8895 (HSDPA 3G)
• Compal Jax10
• Gigabyte M528 (HSDPA 3G)
• SDFR M! PC Pocket (HSDPA 3G, French version)
• Itelco TIM Alice Mobile IDOL (HSDPA 3G, Italian version)

Many of the version comes with Linux pre-installed. However the hardware is capable of running Windows XP. This blog post is about installing Windows XP on to the Alice Mobile / TIM variant. Maybe also applies to Windows 7 or other Windows version as well.

I know this is probably 10 years too late, but if anyone happens to have this machine, hopefully this could be helpful.

Introduction

In case you don't know, nspire CX II is a calculator made by Texas Instruments released in 2018. It has an ARM926EJ-s processor running at 396MHz, 64MB of LPDDR memory, and 128MB of SPI nand flash. Though this is probably already an overkill for a calculator, but, can we get even faster on this calculator? Of course, it would really mean anything. I don't need that additional performance, overclocking a calculator is just like overclocking anything else, it is just purely for fun. If I do need more performance, I would go and pick up a laptop. Let's get started.

Background

To overclock any modern processor, there are two key parts: clock synthesizer, memory controller. The first one boosts up the clock frequency, and the second controls the memory timing to make sure the memory runs at higher frequency (if you are unable to decouple the memory frequency with core frequency). The TI nspire CX II uses a custom SoC which I don't have any documents. The operating system on the nspire CX II is also locked down to disallow any unsigned binary code execution. So to overclock it, there are three steps, 1. Get the "root priviledge" on the nspire OS, 2. Understand how clock generation works on nspire, 3. Write a program to overclock it.

nspire OS

Luckily, the first part has been done by the community. There is a tool called Ndless which exploits some vulnerabilities in the nspire OS to allow unsigned code execution. The version released in September 2019 introduced initial support for nspire CX II. Huge thanks to the ndless team who made this all possible.

Clock synthesizer

The nspire SoC has an internal clock synthesizer (PLL). Since there is no datasheet or manual for the SoC, I have to reverse engineer it to find out how it sets the clock. Luckily, there is a community developed emulator for the nspire CX II, also based on reverse engineering efforts obviously. (Note: CX II suppoort was developed by the same guy who implemented CXII supported for ndless, Vogtinato.)

Introduction

ThinkPad X61 is a classical machine, along with T61 they are the last 4:3 ThinkPads made by Lenovo. I bought my X61s used in 2010 (I simply couldn't afford it back in 2007 when it first came out) and keeps using it as my main laptop (I have a much more powerful desktop PC for most of the stuff though). Many of the components have been upgraded since then, 2GB DDR2 is upgraded to 6GB, 160GB spin drive has been replaced by a 512GB SSD, and the TN screen has been replaced with an AFFS (IPS) screen. The thing that never changed is the processor: the 65nm Core 2 Duo L7500.

X61 comes with various CPU options available when buying new:

X61:

• Core 2 Duo T7100, 1.8 GHz, 2 MB L2, FSB 800, 65 nm, 35 W
• Core 2 Duo T7250, 2.0 GHz, 2 MB L2, FSB 800, 65 nm, 35 W
• Core 2 Duo T7300, 2.0 GHz, 4 MB L2, FSB 800, 65 nm, 35 W
• Core 2 Duo T8100, 2.1 GHz, 3 MB L2, FSB 800, 45 nm, 35 W
• Core 2 Duo T8300, 2.4 GHz, 3 MB L2, FSB 800, 45 nm, 35 W
• Core 2 Duo T9300, 2.5 GHz, 6 MB L2, FSB 800, 45 nm, 35 W

X61s:

• Core 2 Duo L7300, 1.4 GHz, 4 MB L2, FSB 800, 65 nm, 17 W
• Core 2 Duo L7500, 1.6 GHz, 4 MB L2, FSB 800, 65 nm, 17 W
• Core 2 Duo L7700, 1.8 GHz, 4 MB L2, FSB 800, 65 nm, 17 W

However, when buying used, especially in 2020, it is really hard to pick one specific processor. Most of the listings online come with a T7100 or T7300 processor, built with a 65 nm process. If the machine is an X61s, then the 65 nm processor is pretty much the only choice.

Unless the processor can be replaced or upgraded.

It is quite common to replace the processor in T61s, just buy a new processor, install that on to the motherboard, done. Or if one wants to use newer FSB 1066 processors or even quad-core processor, BIOS mod and motherboard mod are available to allow the processor to run on the T61 motherboard.

The X61, on the other hand, has the processor soldered down on to the board, making it harder to replace the processor. And it is much harder to buy BGA processors than just normal PGA processors: pretty much no one would take out the BGA processor from their laptop and just sell that, and it is pretty hard to buy new old stock BGA processors. But the good thing is if the CPU can be indeed bought and installed, all the mods available to the T61 are also available to the X61.

This post is a comprehensive note about how to install probably any Core 2 Duo mobile processors onto X61 if the power supply and cooling allow. And my method uses a PGA processor rather than a BGA processor so the processor is still easily purchasable on eBay or other platforms. Quad-core processors run much hotter and require further ACPI mod which is not described in this post.

I understand that these kinds of mod have been done on X61 many times before. But I just want to document comprehensively how I did it and what each step is.

I am also aware of the existence of the X62/X63 motherboard project. This project only focuses on upgrading the original motherboard.

I used P8600 as an example in this post, but other processors should also work.

All information is provided "as is". I will not be responsible for any damage due to the use or misuse of the information provided. Modding BIOS and hardware is risky and likely to permanently brick the machine if not done properly. Do this at your own risk.

现在如果说起主打便携的笔记本电脑的话，可能很多人都会想到12-13寸屏幕+超低压的处理器这样一个搭配。确实，长久以来，笔记本电脑一直可以分为便携和性能两个流派，前者通常配备了11-13寸的屏幕和低电压的处理器，而后者则通常配备了14-17寸的屏幕和标压的处理器。然而这种划分，在上个世纪，可能并不成立。

ThinkPad的笔记本产品线，在发布之初（1993年）就有3个系列：300系列，500系列和700系列。300系列是廉价系列，500是超便携系列，而700则是高性能系列。首发型号的300、500和700分别配备了8英寸、7英寸和9英寸的屏幕，应该来说都是远小于目前的笔记本的屏幕的，屏幕的尺寸并不能成为笔记本定位的衡量依据。几年发展之后，IBM似乎“忘记”了500系列，使劲出了不少300系列和700系列型号，却不见了500系列的影子。虽然期间IBM推出过一些日本限定的500系列机型，如530CS、535、535E、535X、550BJ和555BJ，但是广大北美和欧洲用户，再一次听到500的声音，则是一直等到了1996年的560。而这次的560，配备了12英寸的屏幕和Intel Pentium 133的处理器。这个配置在当时的产品线中是怎么样一个定位呢？有趣的是，当时主打高端的760E笔记本，也只配备了12英寸的屏幕和Intel Pentium 133的处理器，性能上其实并没有明显的差距；而主打低端的365X笔记本，同样配备了Intel Pentium 133的屏幕，不过屏幕降级成了10英寸的CSTN或TFT屏幕。不难发现这三款笔记本在CPU配置上其实并没有太大的差异，而如果按照现在的标准按照屏幕尺寸去判断定位，那可是犯了大错误了，560是三款里面最轻最薄的，而屏幕最小的365X，用过的都知道，就是个大砖头。所以，大致来讲，这三款笔记本主要就是按照外观设计、功能取舍（如FDD和CD）和价格（而基本没有性能区别，当然性价比包括在了价格因素中），面向三种不同的人群的。

今天要展示的，很抱歉不是560，而是560的小改款560E。因为说白了就是一台IBM PC兼容机，没有更多的值得讲，所以这里也就放几张图给大家看下了。