Issue 117April 2000
Under the Covers
Part 1: Get Embed(ded) with Windowa NT 4.0

AN ALTERNATE PATH

Other than getting to hold a 340-MB Microdrive in my hot little hands, there were other good reasons to call on Ampro to help me get some NT Embedded OS code for you. As you have already seen, the Ampro Little Board/P5x SBC has a few tricks up its sleeve.

The Ampro Little Board/P5x SBC uses either a 166- or 266-MHz Intel Mobile Pentium processor with MMX, known as Tillamook. Its onboard peripheral content is equal to the logic contained on six external expansion boards. It’s fully PC/AT compatible, and there’s more level two cache on this tiny board than on most desktops, 512 KB. Memory tops out at 256 MB and can be either a DIMM of EDO DRAM or SDRAM.

All of the required PC-compatible goodies are onboard—15 standard interrupt channels, seven DMA channels, and three programmable counter/timers. That’s equivalent to the standard Intel ICs (8259, 8237, and 8254, respectively) that you saw on PCs of yesteryear.

There are four 16550-equivalent serial ports, with two acting as RS-232 only. The remaining two serial ports can be mixed among RS-232, RS-485, TTL, or IRDA. The parallel port is standard IEEE-1284 with bi-directional data lines. I was surprised but pleased to see SCSI capability in the onboard Adaptec ACI-7860 adapter. The standard complement of IDE drives is also supported. Of course, floppy drives are supported, and there’s even a 10/100
BaseT Ethernet port just for me! I could go on for another couple of pages, but chances are, your favorite peripheral is on the list.

The Florida-room version you see in Photo 1 runs at 266 MHz and is equipped with 64 MB of RAM. All this horsepower is contained on an EBX 1.1 standards-based CPU module.

To differentiate the Ampro Little Board/P5x SBC from its desktop predecessors, Ampro has made some improvements to the architecture and firmware. Things like a watchdog timer and serial console support are essential items for true embedded operation. The watchdog timer monitors the boot process and is accessible via calls to BIOS. Serial console support is exactly that. Just hook up an ASCII dumb terminal and take charge. Ampro also has included some really neat boot options like serial boot loader, batteryless boot, fail-safe boot, and accelerated boot.

The serial boot loader allows boot code to be loaded from another external serial source. Batteryless boot is another way of saying that the system setup information is stored in nonvolatile EEPROM instead of battery-backed RAM. This is used in the event of onboard RTC/setup RAM battery failure. Fail-safe boot does it until it gets it right. Under BIOS configuration control, the fail-safe boot process retries boot devices until a successful boot is achieved. Accelerated boot is simply whizzing past the POST routines. If those boot options aren’t what your app requires, you can use Ampro’s BIOS extensions to customize your boot scenarios.

I fired the Ampro Little Board/P5x SBC up while I was describing the BIOS enhancements to you. Look at this, the guys at Ampro loaded Windows NT Embedded 4.0 on this little fish.