Zenith Eazy Pc Teardown

Somewhere on the West Coast of Vancouver Island...

I played hookie from Free Geek this week and hung around Vancouver Island. Fortunately I saved up a teardown for just such an occasion.

This one is an ill-advised entry into the world of early home computing and I feel no regret in tearing it to pieces.

Pictured above is the Eazy PC, Zenith's valiant attempt to make the worst PC-compatible computer possible. (This one, the most expensive of the three models they offered, listed for $1699 US according to a very nasty review in September 1987's InfoWorld issue.)

The black-and-white screen and base are a one-piece unit, and the computer itself has almost no capability for expansion whatsoever. Here's the back:

That chunky cartridge is the so-called "Option Connector", where you could attach one of apparently only two custom-made upgrades to the machine. The one pictured here is a 128KB RAM module, extending the built-in 512KB RAM for a grand total of 640KB -- the maximum that this machine could take.

Slightly concealed behind the attached module are the printer (parallel) and mouse (serial-ish) ports. Apparently the mouse port isn't even a full-fledged serial port, but enough of one that a mouse would function.

The only other alternative to the pictured memory expansion is Zenith's memory/modem/serial port option, which included 128KB ram, a 1200 baud Hayes-compatible modem, and an additional serial port. Add another $399 USD.

These option bricks were attached with a ribbon cable:

A terrible, terrible idea

This might just be the worst kind of expansion ever invented. I assume Zenith's motivation for this was a sense that people were afraid of opening up computers and tinkering with the guts; fair enough. So why give them a ribbon cable? These are relatively easy to misalign and aren't at all meant to take a lot of wear and tear. The only answer I can think of is that Zenith was simply too cheap to do a proper job. Putting RAM on the end of a ribbon cable is like leaving your phone at the bottom of a stairwell and conducting a conversation by yelling at it. (Works just fine if you're Bonzo, I guess.)

Another look at a stupid, stupid idea

This model had a built-in 720KB 3.5" floppy drive and a whopping 20MB IDE hard drive. That's right: except for the 1200 baud modem and extra serial port (and of course the stock mouse and keyboard, long since separated from this unit), we're looking at a MAXED OUT Zenith Eazy PC with a list price of almost $1800 USD. And those are 1987 dollars -- today that would be about $3400 CAD.

The rest of the InfoWorld review (available on Google Books) is pretty amusing. Zenith, you blew it. The IBM PCjr sucked for many of the same reasons four years earlier, but at least it sucked for cheaper.

So, a look at its guts, for what it's worth.

Eazy PC, justifiably decapitated

The screen is permanently attached to the base; the screen also seems to contain the power supply for the whole unit, so two connectors come down into the main chassis from there: power, for the motherboard, and video data back up to the screen from the video controller.

(Incidentally: does anyone else remember when power switches used to be on the backs of screens? In this case, the power switch for the whole unit is on the back. I wonder what engineer first did this, thinking to himself "yes, this is where it belongs." Anonymous engineer, we wonder what you were thinking.)

The hard drive is on the upper left of the chassis in the picture below, and just below that is the 720KB floppy drive. The motherboard is underneath metal sheathing -- the only sign that any care at all was put into this design. I would've expected them to line the top of the case with tin foil. You can also see the little PC speaker square in the middle of the chassis. It's mounted on a little custom metal bracket -- a maneuver that screams "Oops, we forgot to find a place for this!"

Under the metal sheathing

Underneath the metal sheathing, you can see the motherboard on the left. This system uses an NEC V40 CPU, which was supposedly PC-compatible and ran at speeds somewhere between a PC and an AT. You can see the square CPU chip at the far left of the motherboard.

On top of the hard drive, there's a white adhesive sticker with a bunch of free space. This is where the manufacturer could document bad sectors on the hard drive -- they often shipped with known defects and the manufacturer would actually print a list of them and stick them to the drive.

Vadem IBM-compatible BIOS

Here's the BIOS chip -- I can't find much information on Vadem, but they appear to be a subcontractor that Zenith used to manufacture some of their computer-related equipment. I suspect most of the compatibility problems that the InfoWorld article described originated here.

Good riddance to this one. If I had a time machine, I'd go back to 1987 and warn the prospective buyer of this ill-facted bit of garbage to spend a little bit more and get one of these instead. (Compaq, why do I love your early portables so much?)

One saving grace for this silicon mistake -- it still boots after almost 25 years. Sort of.