High Treason's Museum

Systems

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High Treason's Museum - Systems - Zawadi \ Quick Overview

Overview

Zawadi on charge - the NiCd batteries still work

By the end of the 1980s more and more companies were beginning to make laptops, but Zenith Data Systems had been in the game for a while. Despite some turbulent goings on in the company, Zenith was usually stills synonymous with quality and this system is a fine example of such. The form factor was far more 'modern' than many of its contemporaries, with its comparatively sleek clamshell design and while color screens might have existed, there was little need for them on a Turbo XT class laptop. Besides, you can get a three hour battery life out of it with this display while running the CPU at the full 8MHz, though this will likely drop if you installed the 8087 Floating Point Unit, or opted to have the hard drive installed.

Our machine did not have such fancy things. Being used by BT engineers, it spent most of its life travelling around and plugging into exchanges via a modem. As such, we instead have the dual floppy drive version, with both being 3.5" 720K and being your only realistic way to load an operating system. Supposedly there should be a header that could be installed, in the back of the system, to essentially externalize the ISA bus and run expansion cards, so technically a huge SCSI drive enclosure isn't out of the question, it just isn't very useful either.

More realistically, we have to ask whether the laptop can do what the manufacturer claimed. Those claims were that the machine was essentially a CGA Turbo XT that you could carry around and, without a doubt, it achieves this nearly flawlessly. It is also a testament to the quality that the machine still does it all these years later without any repairs so far, which is phenomenal when you consider that it hails all the way from 1987.

Is it a powerhouse? Perhaps not, but it's capable and at the time it launched, 8088 systems were selling well, to the point where most software was still being written to work with them. Coupled with how commonplace MDA and Hercules were, despite expensive VGA adapters being over a year old by this point, the Yamaha CGA adapter inside the machine is certainly adequate for most anything you could realistically ask the computer to do. Evidently it was good enough for British Telecom and, also, good enough for the United States Armed Forces, as their mass order was the first of its kind.

Smashed Windows

High Treason's Museum - Systems - Zawadi / Specs

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System Performance

TopBench is the only benchmark completed by this machine - not because it cannot complete other tests, but because there was little point. Like most Turbo XT systems, this one scores identically to just about every other 8MHz 8088 computer with a CGA video system.

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Pictures

The system board takes up most of the base of the chassis. Nonetheless, the level of integration is very high for the late 1980s and it is a 'double sided load', which must have been expensive.

640K of DRAM is available to the system, but cannot be replaced if it fails. The CGA chip has a mere 64K to use, interleaved, which is generally enough.

Yamaha made CGA solutions, but they don't appear to be very common. This one seems reasonably compatible beyond having no composite and being hooked up to a passive matrix LCD.

The CPU is just a plain old 8088-2, the heart of any real Turbo XT. It can run at 4.77MHz for compatibility, or at 8MHz depending on a dipswitch setting. All settings are configured by dipswitches, just like a desktop AT, due to no CMOS RAM or RTC being present. On the bright side, no RTC battery leakages.

You can install an 8087 FPU if you so desire, but if you didn't need it, you didn't buy it. So far as I know, this laptop never needed one, so never had one. You can see the configuration dipswitches nearby.

Zenith distributed the laptop with a slightly modified version of MS-DOS. It largely functions just like regular DOS as far as the user is concerned, which is good because it means most applications will work here.

The 8088MPH demo can be run on the system and functions fine, aside from when you try to use the internal LCD and even then, the demo wants a composite monitor. What we should take away from here is that the system is very software compatible with the IBM original.

A handle is present under the front of the laptop, as was common at the time. This feature should have never gone away. When you look at old laptops, you see little things like that and the contour of the edges and realize: This was designed by people who wanted to use it themselves, and so was made to function.

You get only the bare necessities as far as expansion goes. It hardly matters as there's not much more you'd realistically want to do with it and if there was, you'd probably buy a portable with expansion slots available.

Another shot of the laptop as a whole, with the lid closed. You can clearly see the British Telecom branding. This badge was also placed on some Zenith desktop computers for use by the same.

Inside the battery pack. These batteries could be 'stacked' on the back of the laptop and charged when disconnected from the machine. This is a feature I wish had stuck around.

It is worth noting that the manual is of exceptional quality, where it even goes into programming registers of the CPU and CGA adapter. This was definitely a system aimed at power users and professionals, something that was meant to really be used.

You can click the above pictures to see full size versions in a new window

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System Achievements

Zawadi holds a few records:

• Oldest laptop in my collection - made in 1987

• Most basic 'PC' in my collection

• Longest Battery Life

• Least powerful 486 I own

• Among the cheapest - Approximately £35 cost to complete

Ooh-laa!!!

Videos Available

Zawadi's main overview video, which covers things in far closer detail.

Video for Windows v1.1