RetroObscura SHARP X1

JOHNNY BLANCHARD GETS RIGHT TO THE POINT WITH THE SHARP X1

The X1 is a strange collection of machines.

There are lots of variations for a start, covering machines with disk drives, built-in tape decks and even the Twin, a combination of an X1 and the NEC PC Engine.

The story really begins with Sharp's MZ range of machines. These Z80 based 8-bit computers were part of a long running series, first introduced in 1981. The MZ series was produced by the computer arm and had a fair amount of success, but the TV arm wanted a machine that would fit its own objectives.

And so in 1982 the X1 was born. Instead of the classical computer look of the MZ line, many of the models more closely resembled a high end VCR. It included the ability to mix the computer visuals with an incoming signal and had in-built timers to help schedule video recording through the included TV tuner. All of these functions could also be controlled via software, allowing a degree of video automation. In terms of the hardware, like its predecessor, the X1 was based around the Z80 processor, generally a Sharp clone. This ran at 4Mhz and was paired with 64K of memory. Video RAM was between 4K and 48K, allowing a resolution of 320 x 200 or 640 x 200 on the original models and up to 640 x 400 on later turbo models. It could display 8 colours with later models allowing 64, from a palette of 4096.

The hardware came in a variety of forms and colours, we have photos of the CZ-852CR which is a Turbo Z model. Not only a very pleasing scarlet red colour but it also has two in-built five and a quarter inch floppy disk drives. The machines were also available with built-in tape decks and in other colours, including black and grey. The other X1 we have is the CZ-830C — better known as the X1 Twin. This is the last model of the X1 released before Sharp transitioned to the 16-bit era, with the legendary X68000. You can see the heritage in its design, looking a lot like the classic tower design of some of the better known X68000s. The Twin is so called because it merges two different machines into one. Sharp were not new to this idea, coming up with the Twin Famicom and various TVs with in-built consoles. The Twin took the X1 and added the ability to play games from NEC's PC Engine console.

This was very much just a case of fitting the guts of a PC Engine inside a computer though, the two machines were largely independent, even sporting their own joystick ports. A button on the front of the computer switches the video between the two modes, although it's interesting to note that they do seem to keep running when you switch between them, allowing you to keep your work going when you fancy a

Sharp’s computer arm were responsible for many great computers, including the iconic X68000, but one of the best of its 8-bit line-up was created by its TV unit

game of something. The really useful part of this merging process is that the Twin is usable from a normal composite output, previous X1s required specialised RGB cables and the ability to show 15kHz and 31kHz signals.

Despite adding the PC Engine, the Twin still functions as an X1 computer, sporting a five and a quarter inch disk drive and space to add a second, as well as still having an expansion bay on the back to add card, such as the FM Tuner or 3D glasses controller. The X1 series of computers is a sorely under appreciated collection of retro machines, partly because unlike the MZ range which they helped to end, they didn't release outside of Japan — but also because they were over-shadowed by the X68000, the machine that ended them. It is a shame really, because there are some excellent games available. Their similarity to the previous range of machines means there are a good amount of ports and their advantages in graphics meant Japanese developers took a chance with some titles.

The X1s are starting to rise in price now and the Twin is quite rare. But getting hold of one of the earlier machines at a half decent price is possible, with the caveat that they aren't light machines, so postage will add significantly to the cost. What you'll get though is a fascinating and attractive piece of retro history; they are well-built and robust, with most issues being around capacitors and memory chips. They are considered ‘clean computers', meaning they have no OS built-in, so you'll need software.

They will take a Gotek and with most of the machines being able to use some sort of tape loading, there are cheap ways to get programs running. The biggest issue with the X1 is getting some kind of video signal out. As I mentioned before, many of the models require some way to get both a 15kHz and 31kHz signal. An OSSC on its own isn't going to cut it.

Later models make use of an RGB port, which will let you use SCART for most of the software. Some will still give you problems if your display can't handle the frequencies though. The GBS-8200 board with the GBS-Control add-on will handle most of the cases, but it will require some tweaking for certain titles. The best option is the Twin with its composite output; it seems to handle most of the video issues internally. Unfortunately as the rarest example of X1 it also tends to be the most expensive.

See more of Johnny’s incredible collection of retro systems at

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