Jetway 386WB motherboard

The Jetway 386WB was an inexpensive clone motherboard with an Opti chipset available in the 1989 /1990 time frame.

I’m familiar with the Jetway board because I own one, but many manufacturers in Taiwan produced boards based on the same Opti reference design. Essentially, Opti did the engineering work, and the Taiwan-based manufacturers handled production. The result was an unassuming board that provided good value for money.

Who sold the Jetway 386 WB

These boards, or something functionally identical, frequently turned up in the back pages of computer magazines, especially Computer Shopper. Additionally, small, locally owned computer shops would frequently mix and match off-the-shelf components to build PCs to meet certain price points using this board, or one just like it.

At one time, these shops were much more common than they are today. When you see a generic looking case with a badge bearing a name like PC House or PC Avenue, that case very likely started by as a complete system built by one of these shops. Undercutting the major national brands in price is much more difficult today than it was in 1990, so these stores are a dying breed. But they thrived in the 90s.

The Jetway 386WB, or one of the many more like it was a favorite of these small establishments, especially when outfitted with a 40 megahertz AMD 386. Intel and the major computer brands at the time were pushing the Intel 486, and they were asking a premium compared to the earlier 386 design. The 486 was more advanced, but the optimizations and the built-in eight kilobyte level 1 cache wasn’t enough to outperform a 386 running at double the clock speed. If you outfitted the 386WB with some external cache, that made it even harder for the 486 to outrun it, especially because many entry level 486s eschewed accommodations for external cache because they were trying to meet a price point.

These boards were a favorite among value-minded enthusiasts for about 4 years.

Intel’s counterpoint

One of the big selling points of the 486 was the availability of upgrade processors. They came in various flavors, like the 487 that ran as the same speed as your 486SX but added a math coprocessor, or the Overdrive processors that had a clock multiplier so the overall CPU ran faster. The reason these upgrade CPUs are scarce today is because they didn’t sell all that well. They were more expensive than the equivalent 486 DX or 486 DX2.

The stores that traded in boards like the Jetway 386WB were always quick to point this out. They could sell you a 486 motherboard with the equivalent CPU for very close to the same price as the chain stores charged for the upgrade CPUs alone. The more aggressive shops would offer a buyback program, where they bought back your old motherboard if you bought a new board from them.

The existence of this market was one reason that 30 pin-SIMMs remained on generic 486 motherboards long after the major brands had switched to 72 pin memory. The 486 DX2-66 was a much more compelling upgrade if you could reuse the memory from your 386.

The side effects of trading up

These trade-up programs are another reason why it can be difficult to find clone 386 systems intact. The store you bought it from incentivized you to bring the system back a couple of years later to upgrade to a 486, and again in a couple of years to upgrade to a Pentium. Of course, you could also purchase the components and do the upgrades yourself. It was entirely possible for the same chassis purchased in the late 1980s or early 1990s to start out as a 286 or 386 system and still be in service a decade or so later, toting an AMD K6-2 processor.

386 WB specifics

The 386 WB is a fairly non-descript 386 DX motherboard. My example has the words 386WB silk screened in the top left corner of the board, but doesn’t have any other identifying marks. I used the BIOS string to determine Jetway was the original brand name. When you originally bought the board, it most likely came in a non-descript box that simply said “Motherboard” or “Main board” with no branding, much like the white-label products you find on the bottom shelf of the grocery store underneath the national brand name equivalents.

The chipset

Opti was a chip manufacturer based in California, founded in 1989 by former Chips & Technologies employees. They produced chipsets for 386 and 486-based motherboards in the days before Intel got into the chipset business themselves. When producing a chipset, they also produced a reference design that its customers could adopt and adapt to their needs. The 386WB used Opti’s 82C391 chipset.

The similarity of 386 WB boards from Jetway and other manufacturers is no coincidence. They used the Opti reference design with only minor changes. Taiwan thrived in the 1980s producing printed circuit boards, and using the reference designs allowed its manufacturers to get product to market quickly and at a very low price point.

ISA slots

My example has a total of eight 16-bit ISA slots, although some boards provided one or two 8-bit slots to accommodate boards that didn’t fit in a 16-bit slot.

Memory

The Jetway 386 WB had 8 30-pin SIMM sockets, each of which could take up to 4 MB SIMMs, installed in groups of four. But most people installed four or eight 1-megabyte SIMMs. The 4-megabyte SIMMs were very expensive.

One of the ISA slots has an extra connector on the end. This is to accommodate a memory board to expand the memory further if you ran out of SIMM sockets. Many 386 and early 486 boards had this type of connector, but the connector wasn’t necessarily standardized. Not a lot of people bought them because they probably outgrew the CPU before they outgrew 8 megabytes of RAM. And if you did, it was probably cheaper to trade in the 386 board and the RAM toward a 486 board that could take 72 pin memory rather than messing around with a dead end memory expansion. Clone shops were still buying these boards back well into the 1990s because they knew they could resell them to someone who just needed a cheap system to run DOS and Wordperfect 5.1.

External cache

My example only came with 64k of external cache, but that was a common configuration. More memory meant faster performance, but you noticed the difference going from 0 to 64 more than you noticed the difference from going to 128 or even 256.

Battery

My example did have a nickel cadmium battery, and the first thing I needed to do after I bought it was to remove it and treat the leakage with vinegar. Mine had done minimal damage, but your mileage will always vary. I’ve seen the same battery occur on boards that were 5 years newer and were more catastrophic, so it’s really the luck of the draw.

My 386 WB has a connector for an external battery, so I just rigged up a battery holder with four AA batteries. You could also use a battery holder with a pair of CR2032 coin cells if you prefer.

There’s not much else on the board. The idea really was to buy a system and then reuse as many parts as possible for a generation or two. VLB and PCI obsoleted some of that, but at the time of this board’s introduction, both of those things were far off in the future.

BIOS

The Jetway 386 WB has the standard-for-its-time AMI BIOS, with its garish color scheme. A MR BIOS image exists for the Opti 82C391, and of course I intend to try it in my 386 WB at some point. It uses a 27512 EPROM or EEPROM. But using the utility AMI Setup, I found it was configured to run at aggressive settings, like zero wait states, which explains why Jetway’s 386 WB is a good performer. Running MR BIOS probably won’t yield additional performance but will provide options to throttle the system for better compatibility if needed.

Building around the 386 WB

I built a system around my 386 WB using mostly era appropriate components. I looked in the Topbench database to see what was typical for a 386 running at 33 or 40 MHz. What I found was that a Trident 8900-based video card was a popular choice. 16-bit IDE is pretty much all the same, so I just used whatever 16-bit card I had that worked. I also installed a cheap NE2000 card.

Installing a sound card and CD-ROM is always controversial in 386 systems, but if you have one, there’s little reason not to. Sound Blaster 16s are overkill in a 386, but everyone in the 386 era wanted an Ad Lib, even if they couldn’t afford it, and a Sound Blaster emulates an Ad Lib perfectly while being much easier to find.

Once you have the motherboard, I/O cards, and floppy drives, it’s just a matter of putting it into an AT case. I would have preferred a generic AT style case with a two-digit seven-segment speed indicator. What I had was a bit later, but if I find a case with early-90s styling, I can always move the components into it. I can also install an XT IDE ROM if I want to use a large IDE hard drive or solid state equivalent in the system. For now I’m just using a 128 MB SD card in an adapter.