Most Book 8088s seem to come with a NEC v20 processor, a somewhat faster pin-compatible 8088 upgrade from 1984. The CGA video controller, its EEPROM chip (the one with the sticker, to block out its UV window), and several other odds and ends. An OPL3 sound card module is optional, but it’s a good, space-efficient investment if you want to play a lot of DOS games and you don’t just want to hear the beep-boops of the built-in speaker.
There are three kinds of components inside the Book 8088. There are the genuine original parts, most notably the processor itself. There are the newer chips that are consolidating or simulating the behavior of old ones, letting the laptop do the same things as the 5150 in a smaller amount of space. And there are the bits and pieces of newer hardware (relative to 1981) meant to bring a handful of modern niceties to the Book 8088 that original PC owners could never have imagined.
The Intel 8088 processor included in the Book 8088 is genuine vintage equipment (though mine actually shipped with a NEC V20—more on that in a bit), and there’s an open socket available for an Intel 8087 coprocessor for floating-point math operations. FPUs wouldn’t become integrated into the processors themselves until several years later in the 80486 and Pentium generations, and as a result, few apps actually leverage the 8087 when it’s present; the makers of the Book 8088 recommend only installing one if you truly need it for something specific, since it nearly doubles the power draw of the system and tends to run hot.
The Motorola 6845 CGA display controller (not a “GPU” in the modern sense) is also original. And if you opt to get the Book 8088 with a sound card, you get a tiny board with a Yamaha OPL3 on it, the same sound chip at the heart of some (significantly physically larger) Sound Blaster cards.
Most of the chips in the Book 8088 do the same thing as the chips in the original IBM PC, but they take up less space. The 640KB RAM is provided by one 512KB chip and another 128KB chip rather than being added a few kilobytes at a time on the motherboard or via a bulky RAM expansion card. The total of six 8KB ROM chips in the 5150 (8KB used for the BIOS; the others used to store the Basic software that could boot when there was no other OS present on a floppy or hard drive) are replaced by a single 64KB EPROM chip.
Many motherboard and graphics functions are also consolidated into complex programmable logic device chips, or CPLDs. CPLDs are essentially chips that can simulate the functionality of other chips, like simpler versions of the FPGA chips that are used to recreate retro game consoles inside of new hardware.
Finally, we get to the hardware that never could have existed in any form in a vintage IBM PC. Hard disk functionality is provided by an integrated XTIDE controller, which makes it possible to connect 16-bit parallel ATA storage devices to the 8088’s 8-bit data bus; it enables a connector for CompactFlash cards, which are essentially SSDs that use the IDE/ATA interface.
There’s also a CH375S chip that powers the USB port. This isn’t a traditional USB controller, and the USB port in the Book 8088 can’t do most of the things a USB port can do; like the XTIDE controller, the CH375S allows storage devices to interface with the PC’s 8-bit bus. So you can use it for external USB storage drives but not for mice, keyboards, or anything else.
And finally, there’s an LCD screen connected to the Book 8088’s video hardware via another board hidden beneath the device’s thick display bezel. The screen uses a 50-pin ribbon cable, and a Realtek RTD2660 controller chip bridges the ancient display chip and the modern LCD; 7-inch screens like this and RTD2660-based boards are available for Raspberry Pi-based projects, though the Book 8088 comes with no other display outputs, brightness controls, or other basic functions.
The Book 8088 does support 8-bit ISA expansion cards via a dongle that plugs into the back. If you were to add extra ports for mice or gamepads/joysticks, a storage controller for floppy drives, or any other kind of hardware to the Book 8088, this would be the way to do it; we didn’t buy the version with the ISA dongle, so all we’re talking about is the laptop itself.
For all its other flaws, which I’ll enumerate in the next section, the inside of the Book 8088 is remarkably clean and well-labeled, and the AliExpress seller even sent over a wiring diagram, technical reference manual, and the BIOS source files after I bought it (as far as I can tell, these files don’t exist anywhere else on the Internet, so I have uploaded them to Ars’ servers and linked them for posterity). It’s clearly the work of someone who cares about making their work reproducible and moddable, though I can’t find any markings on the motherboard or elsewhere that actually tell me anything about who made the system or why.
