The latest home computer from Sinclair is the ZX Spectrum+. What sets this computer ahead of the other Spectrums is the larger keyboard with extra dedicated keys. The Spectrum+ looks a lot like the QL small business computer but with a few less keys and no microdrives attached to the side.
The keyboard itself has more of the feel of a “large” keyboard, more so than the 2068 does. Pull-out legs are also provided in the rear to prop up the keyboard at an angle for more comfortable use. A reset button is located on the left side to get out of any crash situation or to start all over.
Dedicated keys include the arrow keys, the period and comma, quotation mark, semicolon, true and inverse video, single key extended mode, caps lock, graphics, edit, delete, break and an extra symbol shift key on the left side. One thing that annoyed me was the placement of the break key which is just to the right of the zero key. Most computers have the delete or backspace key there. Why change it?
The connections on the back are in the same locations as on previous Spectrums. In fact, the circuit board inside is the same as well, so that Spectrum owners’ can now buy upgrade kits to fit old Spectrums into this new case. To carry this a little farther, you could even fit the TS 1500 circuit board inside this case and it would work as well, even with the keyboard! Of course the key words don’t all line up, but the alphanumerics are all correct.
On the circuit board itself, none of the integrated chips are socketed except for one of the two ULA chips. Suprisingly, there are more IC chips than in the 2068, on a much smaller board.
When you get one of these things, you need to supply your own power supply. The power supply that came with the TS-1000 and 1500 works nice as long as you either change the plug at the end of the cord to a coaxial type as found on the 2068 with center negative, or you can mount a new socket in the computer itself to match the plug that already exists on the power supply cord. If you don’t have a power supply sitting around, any of the replacement Atari game power supplies work just fine on this or any of the ZX81/TS-1000 or TS-1500s.
Because the Spectrum is designed to work on the PAL type TV system, you need to supply your own RF cable to connect to a TV with a UHF tuner. The channel for viewing is around 36; be prepared to adjust the vertical hold on your set. My Spectrum gives me a very good picture with little to no interference (squiggly lines, grid pattern) .
There is no monitor jack on the rear of the computer, but one can easily be added. I used a chassis-mount RCA type connector and drilled a hole next to the RF jack so that the new jack will fill in the space between the modulator and the rear leg assembly. Connect the center pin to the nearest wire leading into the modulator (goes into the side center of the modulator). The outer ring goes to the case of the modulator. This alone gives a good picture on most monitors. To get a little brighter, sharper picture, locate the 2.2K (red, red, red) ohm resistor which is second from the rear in a row of twelve resistors just in front of the left side of the modulator and jump a 4.7K (yellow, violet, red) ohm resistor across it. If you get any tearing of the picture, use a higher value resistor.
Color is another story. Probably the biggest difference between the TV standard used here (NTSC) and the one used there (PAL) is the way color is added to the picture. The simplest way around it (if you need color) is to buy an RGB interface for the Spectrum and use it with an RGB monitor. The poor man’s way is to change out the color burst crystal. The computer comes with a 4.43 MHZ crystal which is the frequency used in the PAL TV system. With NTSC, the frequency is 3.579545 MHZ, so run down to your local electronics parts store and pick one up (Radio Shack sells them for around $1) and swap crystals out.
Doing this, I get a beautiful blue and yellow, but other colors are just so-so. On older Spectrums, all you needed to do was change out the resistor and capacitor values in the color circuit to match what is used in the 2068. Unfortunately, this new version of the Spectrum marked issue 6A uses a different video processor (SN94459) and I have yet to get a schematic for it, so we’ll have to live with the colors the way they are for now. The second crystal can be changed out to provide a more stable picture. This crystal is 14MHZ, whereas the 2068 uses a 14.112MHZ crystal. (Good luck finding this other crystal unless you happen to have a junker 2068 laying around to pull parts from.)
I enjoy using this new Spectrum – particularly the keyboard. All Spectrum software runs on it with no problem, giving you access to over 5,000 programs. Even now, Spectrums are one of the leading home computers in England, giving Commodore, Atari, and others fierce competition. The Spectrum+ is available now through English Micro Connection in Newport, Rhode Island.