Sinclair QL

I can't help adoring the Sinclair QL, despite its flaws. I never saw it back in the day, but having read Spectrum magazines I was vaguely aware of the QL. As a "business machine", it was awe-inspiring to a mere mortal, but also somewhat boring with its lack of games and entertainment.

Although it was marketed as a cheap alternative to other serious computers, it was still so expensive that I was just as likely to own one as I would an Cray X-MP. Now that I have one I can bring one more childhood fantasy to a closure...

Suprematist, constructivist, neo-plasticist... pick one.

The Sinclair QL is a very pretty object. Rick Dickinson's styling is deservedly award-winning. 80s designers were mining influences from early modernism, fundamental stuff like Van Doesburg, Rietveld and Mondrian. I think it also shows here, even if indirectly. The result is straightforward and stylish, yet somehow playfully geometric. None of this rounded-corners nonsense we have to bear today.

The integrated nature of QL strikes as somewhat odd, as Sinclair had previously promoted modularity to make home computing affordable. The cynic might say that was all a marketing ploy anyway, forcing people to build their "cheap" computer in a piecemeal fashion, ending up with an expensive kit with wobbly connectors. The approach also led to an undesirable diversity of peripheral standards.

With QL, pretty much everything that was sold separately for the Spectrum is found inside one casing: Two Microdrives and ports for serial, controllers and network. Happily, a cheap television set could still be used as a monitor.

OK, it might not be as good as a proper keyboard. But it looks so much more interesting this way! 

The execution was marred by the slow speed of the machine and the inclusion of the idiosyncratic storage format. Peripheral connections are mostly non-standard. Instead of a character display, there are only bitmap modes, which makes text display very slow. Also, there are still only 8 colours. The QL no longer suffers from the colour clash, but then again it does not benefit from the rapidness of a coarse character/attribute resolution.

BASIC, not so basic

Much has been written of the above flaws and I will not retread this territory further. I'll instead focus on using the QL with the built-in SuperBASIC, which is one of the more fascinating aspects of the computer. It is unusual to have a BASIC ROM in a machine touted as "serious" as the QL. To me the inclusion of BASIC shows that the QL design philosophy shares still more with the older generation of 8-bit home computers, rather than with the more serious machines and the16-bit generation of home computers that was to come after.

It was common in the early days to include a BASIC programming language in the home computer as the primary operating system. Some might think the BASIC scene of the 80s was one of the more laughable aspects of the home micros, but I'd say a BASIC in ROM is a pretty clever choice considering the limitations of the hardware. The BASIC home computer setup combines calculator, graphic notepad, data storage, text functions and of course, a programming learning environment. 

It's hardly original these days to point out that something may have become lost in the transition to graphical desktop oriented computers. But what was that something lost? Perhaps the example of QL points in this direction. The QL BASIC is not as simplistic as those included in the smaller computers. It has features that make me think this approach might have grown to become something more significant.

QL allows a glimpse to an alternate history that never really came to be: An era where graphical interaction becomes important, not via mouse and icons, but through keyboard, powerful procedural command sets that can be used to access line graphics and windowing in a hierarchical way.

What's so neat about SuperBasic's procedures is the ease and transparency the programmer can add to the existing command set. Let's imagine: The QL is turned on. The computer automatically boots up a BASIC program from the Microdrive, which activates a command set I have prepared earlier. (We'll assume an ideal world where the drives actually work).

The set gives me customized commands for defining objects in three-dimensional space. WALL, ROOM, CHAIR, DOOR procedures have been defined in this way, and can be used for fooling around. Each command draws the corresponding object directly to the screen, rendered from the chosen viewpoint. Should I want the objects to behave differently, I can of course change the contents in the procedure definitions.

Left: Drawing on-screen with the created procedures. Right: A "house" written in BASIC.

A more hierarchical space can be defined by writing a program listing that makes use of these procedures. I create a building out of rooms and corridors, after I have reached some idea how I want to position them. The rooms are adorned with windows and doors, and also contain objects such as chairs and tables. I can use the BASIC program to give the rooms some logic of their own. For example, changing the room dimensions might even re-arrange the furniture within.

If I get tired with the conventional furniture objects, I can redefine the procedures to do something more interesting. Furthermore, all graphical output in the objects is driven through one self-defined procedure which draws the necessary lines. By changing this principal procedure, the outcome of all the other commands also changes. Depending on how the line procedure is written, the view becomes three-dimensional, overhead or an elevation... or the lines and coordinates are randomized and distorted, producing more unconventional outcomes.

Left: Changing the perspective to a side-view. Right: Changed foreshortening and background colour.

In principle, the above could be made to happen with the QL. As a matter of fact, I have tried to demonstrate how this could begin to work, even though this work hardly represents the idealized vision above. But I also specifically did not want to plan too much ahead, as I wanted to experiment with the fluidness of this process. There's something to be said for a mixture of interpreted commands and a program listing, which tends to become lost in a compiled-only language.

The pictures here are a result of about an hours work. It shows to me that the environment is "graphical", despite all the command lines, much like in a good LOGO environment. Without any dedicated drawing package, the QL BASIC could be used to create a rudimentary setting for spatial design exploration. In my mind, here's something more at play than the rather limited idea of a "office desk metaphor" that Apple was peddling to their customers.

With the QL, the graphical component is not presented as a way to make the computing experience easier, but more expansive. Of course, this vision is demanding, as it requires at least some programming skill and some understanding of design exploration.

The video below shows the reality: The lines are extremely slow.

So it might not look much, but this is on a cheap-ish computer from 1984 and pretty much possible out-of-the-box. The BASIC environment becomes a way to access all that the computer does, and it can get pretty interesting with the graphics built-in. In similar vein, the ZX Spectrum already provided a programmable graphics pad. But it is the procedure definitions in a language interpreter setting that bring the QL experience to a whole new level, and at least in principle, the Microdrive allows a rapid retrieval of these command sets. It becomes as easy to type WALL 100,0 as it is to type line drawing commands.

Now, if I were more interested in writing novels or calculating spreadsheets, the QL BASIC might offer less openings out of the box. The truth is, the QL BASIC environment is not enormously flexible towards all kinds of interests. But who knows, what might have happened if this approach had become the mainstream. Instead, we now have computers mostly as platforms for launching applications that achieve fairly limited things. Programming tends to be accessed through counter-intuitive development environments, not very encouraging for direct approaches. (Although it has to be said that projects such as Processing and Python have somewhat helped change that.)

Highlighting different objects with a variety of colours. The TABLEs are made from LEGs and PLANEs,  whereas the PILLAR is a ROOM with a fixed width and depth.

All in all I have liked to play around with the QL Basic, perhaps more so than with other old computers. What I've been here trying to say is that there is an underlying design vision in the QL that continues to intrigue me, and not so much the somewhat flawed computer QL turned out to be. It's of course not fair to criticize a 30-year old piece of electronics, and I know the story of QL did not end with the Sinclair machine. Perhaps I'll be able to get a later version some day, and see how the story continued.

Schneider EuroPC

More of a picture show again, I haven't been able to get this fully working. I've got some beeps out of the BIOS but as I do not have a display, I'm unsure about the performance of this unit.

(Edit: It does work. Check this blog post for more info.)

I would not have guessed that I'd see PCs as being very nostalgic as yet. But it's true, some of the more "family-friendly" brands of PCs have been around for more than 25 years. EuroPC's appearance owes to Amiga and Atari ST, with everything inside the same unit. Compared to these multimedia machines, it's a rather laughable set: 8088 processor, Hercules/CGA display adapter, beeper sound.

I think it has 512 k of memory instead of 640, no hard drive as standard. As an entry-level PC, it would have been nice, I guess. It would run word processors and things like that quite well. Learning how to use a PC and MS-DOS might have been important to many at those times, and why not take this route? I'm still glad I had an Atari ST instead, though.

It's yellowed somewhat...

The motherboard is not that big compared to the case. It goes to show how PC tech was actually quite small at that point. There's no need for ventilation, fans and big internal power supply units which took quite a lot of room in the more serious models.

Looking inside, the layout's not much different to Amstrad CPC or Sinclair 128 machines. It's also tempting to draw some comparisons between the general layout of EuroPC and Sinclair QL (Board at the middle, expansion space to the left, storage to the right.) Of course, here one of the more attractive aspect of PCs is lost: It's not very expandable. There's only one (8-bit) ISA port, no room for hard drive etc.

Squeezing somewhat, the heart of the computer could fit in 50% less width.

Doing some net searches, I've learned that pretty much the same hardware was also packaged as Sinclair PC200 and Amstrad PC20. There seemed to be some kind of minor rush to get these "desktop" PCs into the market, that vaguely looked like Amiga or Atari, to try to ride on their success. This I think was largely a failure, but Schneider EuroPC, I've understood was still a pretty popular and well regarded computer. I don't have the numbers but I'm a afraid it might have been a bit too expensive compared to Amiga 500 and the likes, on face of the lack of features. I do remember this being advertised back in the day and that was at least my impression back then.

At the bottom of the picture, the external hard drive connector.
It has the most pins ever I've seen in an external connector.

The hard drive, I though initially might have something to do with IDE, but not really. It might be possible the computer can be made to work with IDE hard drives with an 8-bit card. I could work with floppies, though, it's not like software back in the day was very big.

For me, the display issue is the biggest turn-off here. There's a 9-pin connector for a display at the back of the computer, and as I've learned a VGA monitor does not easily connect to this computer.

Three options seem to present itself: 

1. Connect to some monitor from that time: CM-8833-II, or Commodore 1084, with 9-pin TTL inputs. 

2. Buy a 8-bit VGA adapter card. 

3. Get a video-adapter box that transforms legacy outputs into VGA.

Options 2 and 3 would somehow miss the point, as lot of the "feel" of using this computer would be lost. But I would also be disappointed to get one of those old, large displays which are not guaranteed to work anyway. So, it looks like I won't be using this computer anytime soon.

Edit: It's possible to make a CGA-Scart RGB conversion box and connect to an RGB display. It's somewhat more complex than a simple RGB cable, though, but probably the best option now.

Case possibilities

This does not preclude from thinking about interesting casemods. What impresses me with the EuroPC is that the case and the chassis that keeps the keyboard together are very well designed for dis-assembling and putting the computer together. Nothing like the Amigas and Ataris which were really painful to tear apart. Also, the keyboard unit lies on a sturdy metal frame, which is simply laid over the plastic bottom. 

Please tell me it was designed by Germans, I'll believe it.
The computer almost looks prettier without the plastic top.

Opening the plastic case requires finding the correct points at the backside of the seam, but after knowing this the process is simplicity itself. These are pushed in and the lid lifts from the backside and then sort of hinges upward from the front. Some force needs to be used, but also some care, as the plastic clips may break. After the backside has been loosened the case top has to be yanked out with some force and it will come loose. 

Opening the case with a flat-head screwdriver.
Starting from the corner, the clip positions are pushed in and out one by one.

Then there's one cable that connects to the metal frame, but this is not screwed in. After taking it loose the metal frame can be pulled out and turned upside down, hinged on the ribbon cable that connects it to the motherboard. If there are screws that keep the case together, I don't think they are required. The screws that keep the floppy drive in position need not be removed. 

Attention to detail.

I'm not too keen to get the EuroPC up and running, but maybe I would not want to ruin it entirely either. Because the insides are so nicely arranged, one could fit many quite interesting things under the frame. The depth of the board is something like 17-18 cm, so possibly, a ZXevolution, or any modern motherboard with mini-ITX form factor might be made to fit inside. (Dunno if the mini-ITX boards are a bit too tall, though, what with the heatsinks and all.)

However, the keyboard is not something one can easily make work with these solutions. So there would have to be either a complete rewiring of the keys (again!) or a modern keyboard, which would be a bit difficult to fit.

The keyboard membrane

I had to have a peep into the keyboard unit, and no, I don't think there will be any "rewiring" of these keys.

Click to zoom in. It's awesome.

Looking inside the keyboard unit reveals what is, apart from a very few exceptions, an one-layer keyboard membrane. I wonder if it is computer-generated, because I can sort of see the human brain getting a bit messed when trying to come up with something like this. Each of the keys complete the circuit, rather than push together two layers. As the connection points for each one key are somewhat apart, other lines, unrelated to that key, can go between the connection points. Nice.

Canon S-90

This is an electronic typewriter from the era when computers and word processors were already going on quite strong. As it is fully electronic, it is really more like a printer with a keyboard. There's not that much to say, because I could not get the case open. There's some knack to opening it other than "pulling really hard". The screws came off easily enough so I don't think it has been intentionally prevented, it's just I don't get it. I'll see about it later.

The S-90 has a card-type connector to the left side which I suppose enables more typefaces. The right side has a 9-pin type connector. This means the typewriter could act as a printer to a home computer. I doubt the printer has any processor or memory as such, but a dedicated controller that manages the LCD display and keyboard input. Only one row of characters can be edited before they are printed.

I would be interested in the innards, as it might be possible to house a computer board inside the case of a typewriter and make use of a rather excellent keyboard. However, I would probably not want to ruin such a cool looking device as this one, but it's an idea I've been toying with. Occasionally, it's possible to come across really cheap typewriters such as this, but most I've seen in net auctions and such are a bit overpriced. I'd also avoid any mechanical and electromechanical typewriters, because rewiring their keyboards is probably a different game entirely.

Spectrum/SVI summary

It looks like a Spectravideo, but inside... the soul of a Spectrum.

Often people try to find ways to cram a big, modern computer into a very small case. This is not one of those times. Here, a small ZX Spectrum motherboard is placed inside a roomy SVI MSX plastic case, and the keyboard has been rewired to suit the Speccy. Although the project is not really finished (None of my projects properly do), it's not likely to change much in appearance.

Someone may notice I have moved the arrow keys to the front, but they are not yet connected. I'm currently looking at a more elegant way of making the extra keys work, but this will have to wait a little.

I've been playing some games with this nice keyboard, and it really is an improvement over the ol' rubber. The SVI keyboard is near "business" quality and all the keys are pretty much in the places you'd nowadays expect. It also feels better than the Spectrum+ keyboard, and as the keys are better positioned than in the later models, it might be even better than +2/+3 keyboard. Make no mistake, though: it's not possible to speed-type with the Spectrum no matter how good the keyboard. There's just simply something a bit strange with the way the Spectrum handles key input. For playing games, it's good.

It's a bit funny feeling, using another retro computer keyboard to play games with another. Some might consider the whole thing a heresy, but to me it feels more "right" than playing Spectrum games on a PC keyboard.

Formerly known as the Spectrumvideo.

I removed the Spectravideo/SVI decal and made this little thing to replace it. The piece is a leftover from that one time when I mutilated a Spectrum +2. As I could not honestly call this a Spectrum +2, I scratched parts of the text away. So I call it the "Spectrum +_".

The image below shows how all ports find their place in the SVI case. I only had to carve the widest hole a little wider to make the 9V DC IN accessible. The Divide 2k11 required some additional cutting, because the NMI button is on the "wrong side". The normal Spectrum peripherals fit quite nicely. 

Power disconnected.

It's possible that I will eventually install a power switch to the case. Now I have just brought in the power cable from a hole in the right side of the computer and again out from the back (the exit is just about visible to the left). This prevents the cable from falling off the table, at least... A power switch might made as an extension to this idea, that at least would not change the Spectrum board in any way.

SVI/Spectrum keyboard, continued

As a continuation of the Spectravideo/Spectrum keyboard modification, I needed to get a bit deeper into how the key combinations work in the later Spectrum models to replicate the effect in my keyboard. Converting the SVI keyboard to function as the normal Spectrum keyboard was simple, if tiresome. The Spectrum 128/Plus has dedicated Delete, Edit and Arrow keys, and these pose additional problems for the hobbyist keyboard builder.

So, once more, from the top:

Similar, yet different... the delete (backspace) in the old Spectrum requires
pressing two keys simultaneously.

With the old Spectrum, it's clear how one keypress is transmitted to the computer's brain. (The ULA chip plays an important role in this but I need not go there) The row and column connectors form a matrix, where each one key produces a unique combination in the table. But, when multiple keys are pressed, such as combination of CAPS SHIFT and any key, multiple connections are also made.

Pressing a single key, a connection is made between
the row and column connectors on the Spectrum  motherboard.

Here I am using DELETE function as the example key, and it is also the first one I am physically building. With the rubber-keyed Spectrum, the typist had to press both CAPS SHIFT and 0 (zero) key together to backspace(!) Using these kind of compromises, designers at Sinclair could reduce the amount of keys to 40, which is exactly 5x8.

Pressing CAPS SHIFT and 0 together on the old Spectrum gives the backspace function. 

The later Spectrum keyboards have a dedicated DELETE key, among a bunch of other new keys. Yet there are no more connections in the Spectrum+/128 keyboard membrane than in the original. In fact, these newer keyboards ought to be perfectly interchangeable with the old Spectrum keyboards. Looking at the keyboard membrane of a 128 reveals a mish-mash of wires:

A Spectrum 128 keyboard. Slightly more complex.
(Click the picture to get a bigger version)

Pressing the Delete key therefore has to produce exactly the same kind of connections to the motherboard as when pressing CAPS SHIFT and 0 on the original Spectrum. So far, this is pretty clear: Even with the Plus keyboard it is possible to get the "delete" in the old fashioned way, by pressing CAPS SHIFT and 0.

The DELETE key is pressed. (Simulating the Caps shift and 0 key)
The elements in the tri-layer membrane are brought together simultaneously.

How the plus/128 membrane works is that it seems to have three membrane layers instead of two. Each combination key press produces the needed connections mechanically. I've not verified physically that the Delete key especially needs all the three layers, but just to be on the safe side I have based my SVI keyboard work on this assumption.

One clear message here is that both of the connections must be activated only for the duration of the key press. For example, it is not possible to have one wire permanently connected as it would mess the entire keyboard functionality.

Building the SVI key

After clarifying the keyboard mechanism visually to myself in the above manner, I could encourage myself to replicate the way the connections work in the extra keys of the plus/128 model. This requires a further modification to the SVI keyboard circuit board. I have cut the normally two-sided keyboard element into a three-part one, mimicking the way the three-layered membrane works.

Simplified view of one key in the Spectravideo keyboard circuit board.
Left: The normal, two-part connector. Right: The modified, tri-part connector.
The dotted circle shows the estimated area covered by the conducting "peg" in the key above. 

I have built the Delete function into the SVI backspace key, and it works. Just about.
This hack is problematic because the conducting peg under the key does not so easily cover all the three parts. So, even if the theory is sound, the key is not very responsive.

Intermission: The Horace trilogy

In all their 16k glory.

I hardly collect games, but this time I wanted to acquire physical copies of the three original Horace games for the Sinclair Spectrum. They are not rarities, on the contrary, one of them is probably available at any one time on eBay for a reasonable price. The cartridge versions fetch good prices, though. Well remembered and surely nostalgic, Horace games hail from around 1982-1983. It makes me think how time has passed: at the time of their release, films such as "Rebel without a cause", "High Noon" and "Forbidden planet" were about as old then as these games are now!

These are pretty nice games given that they fit into 16k. I'll dismiss the fourth Horace game as it is not written by William Tang and thus is not "canonical". Let's see what the trilogy has to offer...

Hungry Horace:

I'm surprised they did not call it Hungry Horace 3D.

"Inspired" by Pac-man, Hungry Horace introduced the Horace character to the masses. The maze is simpler than in the Namco game, except that it has the occasional overlapping portion. In the first maze there is only one opponent, a park guard, chasing Horace. Horace eats flowers, but does not have to eat all of them. Ringing the alarm bell reverses the situation for a while: now the guards can be "thrown out" of the park. The instructions make it pretty clear that no one dies in this game: if the guards catch him three times he will merely not be allowed around the park anymore.

To distinguish himself from his yellow colleague, he has the dignity of having no gaping mouth. Horace is all eyes and feet, a kind of anti-pacman. As a further reversal Horace is also blue, which in video-speak is the opposite of yellow. The lack of mouth also cleverly symbolizes hungriness, as who could be hungrier than a man with no mouth? Then again, who says those two openings are eyes, as I've always assumed? Perhaps he has not one, but two mouths. Or maybe they are nostrils. Is that protrusion a hand, a tail, ponytail or some other appendage? The mystery remains...

Horace goes skiing:

One of the earliest examples of product placement in a video game: MH Hardware.

I always felt this was the quintessential Horace game, with the most rewarding overall gameplay and the best title: Horace goes skiing. These later Horace games were clever in that they "homage" not one, but two arcade hit games. HGS combines elements from both Alpine ski and Frogger. Horace has first to grab a pair of skis, conveniently placed on the other side of a densely trafficked road. The traffic is pretty fast and changes in density. Each type of vehicle has a different speed. Choosing the right moment to cross can be a nerve-wracking exercise, as the choice has to be made with intuition coupled with a grain of luck.

Should Horace suffer a traffic accident, an ambulance will helpfully drive to the rescue. The ambulance also patrols the road while Horace attempts to cross it, and it's not rare to get smackered by it, as it is the fastest of the vehicles.

It's karmic. No, wait, I meant kathartic.

After getting the skis, he has to return to the other side of the road. Then the downhill skiing, the "Hannekon run" (No I don't get it either) may begin. This is the more relaxing part of the game, but it is not wholly without danger. Should Horace break the skis, he has to rent another pair. All the collisions with the cars and the trees make pretty nasty viewing, in contrast to the strictly non-violent nature of the first game. But in fact there's really no ill-will demonstrated, it's more like educating the kids about the dangers of traffic and skiing. Don't go outside, it's a scary world out there. Better sit in front of the computer and play Horace.

The idea of a two-part game is successful as the good gameplay is rewarded with further, different gameplay. The later part is also easier and somewhat more relaxing compared with the hectic streetscape. This further reinforces the idea of the second part as a reward to the first.

Horace & the spiders:

"Hungry Horace and the spiders ... from Mars", one could almost say. By the third game, Horace's stature as a major British cultural export began to equal that of David Bowie. As a final tour de force, Horace & the spiders features three parts, completing the trilogy with a three-parter of its own. Thus the Horace trilogy is structured as an ever more intricate spiral of complexity, beginning from the humble pacman-like beginnings of the first game, and ending up with a metaphorical recapitulation of the trilogy itself: Wheels within wheels.

A spider.

I'm not sure if the first two parts of this game resemble any single game in particular, but I would not be surprised that it has some direct precedent, possibly Jungle hunt. (Another might be Smurf rescue on the Colecovision). Horace runs across a scrolling landscape, jumping over some spiders and trying to avoid getting tripped over by a cliffside. The first dash game, if you will. There is no clear conclusion to the part, the action instead "jump cuts" to the second part.

 Ironically, the spiders' best weapon contributes to their demise. 

The second part has Horace crossing a chasm, hanging from threads that descend from live spiders. Gripping stuff. The third part, however, "references" Space panic: Horace climbs the spiders web and stuffs the spiders into holes he has created by stomping with those two enormous feet of his. I've felt this is one of the best parts in any Horace game ever, but it was damn hard to get here, as the first two parts can be frustratingly annoying. In a way the format established in 'Skiing is also used here: the game rewards good gameplay with a better, more interesting game, which is also less stressful than the lead-in parts.

Although the instructions again stress that Horace does not die, but merely has to give up the hunt after all his "serum" has been lost, the game is hardly non-violent. Horace is set out to kill the spiders, stomping them with glee. So the Horace trilogy also represents an deepening spiral of revenge and retribution. Previously, the world was intent on squashing Horace, now it's payback time. One gazes into the abyss and so on.

The heart of darkness: the web thickens...

Conclusion

I do not think much of Hungry Horace, as the game goes nowhere, but the two later Horace games are pretty cool what with the multi-part structure. The combination of two different genres creates a surprisingly fresh and original atmosphere, almost like playing two different games in quick succession and pretending they belong together. The consistent graphic styling make nice use of the Spectrum platform, using the graphical limitations of the computer to convey a suitable abstraction rather than trying too hard for naturalism. The cohesion of the trilogy, both thematically and in appearance, contributes to a mysterious atmosphere that begins from the naive scenario of Hungry Horace and ultimately descends into the dark violent nightmare that is the final screen of Horace and the Spiders.

Work in progress: Spectrumvideo 48k

The 48K Spectra. Or the Spectrum-Video ZXSVI748

I happen to have a Spectravideo MSX 728 in poor condition and as it is unlikely to have any other future, I wanted to try to use its keyboard for some project. My thoughts went naturally to the ZX Spectrum. First I toyed with the idea of building a new case entirely, but pretty soon I was positioning a rubber-key Spectrum motherboard inside the Spectravideo case. 

The 728 case is huge, so it's not a big challenge to fit the board inside. I was pleasantly surprised to find out that the openings for connectors are already in very useful positions. 

Trying the motherboard for size, before removing the screw holder.

Only one screw holder has to be removed and something needs to be done to the power supply connector. The question at the moment is if all important peripherals work, despite the good fit. An Interface II type flat peripheral poses no problems. The vertical modules may be a bit more difficult, as they collide with the backside of the computer. At least I'd like to connect the Divide 2k11 to the finished computer.

Looking from behind: 9V, Peripheral connector, tape connectors, TV out.

The Spectravideo keyboard unit.

The SVI keyboard is a removable unit with a straightforward matrix-type connectors. The matrix wiring is very convoluted and it's not really possible to salvage any of the existing lines, so the simplest thing to do was to severe all connections between the keys and create new lines.

The existing connections are destroyed by sawing between all the key positions.
As can be seen, this is not yet the full treatment.

Again, I am torturing my woodworking saws: The result is ugly, but it works. It also feels like the most disrespectful thing I've ever done to someone else's design.

Another option might have been to do a new circuit board, which would have been a first for me. As the board is quite big and would have to perform well against wear in a mechanical/electrical role, I did not want to try such a thing as my first board project.

The ZX Spectrum membrane connections are first drawn for reference.

The most gruelling task is putting the new connections in place. The only way for doing this I could come up with was to join each connector with a small wire, trailing from hole to hole. After drilling two small holes next to each of the connectors, the wires could be then be laid underside the board. (I used a 1,5mm metal drill.) The wires are pulled to the topside, where they are soldered to the key connections. Each of the keys is connected twice, for the matrix columns and rows. 

Between the circuit board and the plastic keys there is the rubber mat
that holds the conducting pegs.

I now have the normal Spectrum keys working. The keyboard is connected and in place. The keyboard works very well with the Spectrum, and it is certainly nicer than the rubber keys or the Spectrum+ keyboard. The contacts work well even if I'm not a very experienced in soldering. There is enough leeway in the rubber "domes" underside the keys, so it does not matter that the soldering is a bit lumpy. This in mind I'd say the SVI keyboard is very good for this kind of mod. 

Testing the keyboard connections.

The neat things are yet to come. Now that I have the essentials working, I can start thinking how to wire all the SVI special keys and what they might do in the Spectrum context. To get keys like comma and period working directly on the Spectrum, I have to connect them both to the symbol shift and the relevant key at the same time. 

There's also plenty of room inside the case, so that's another possibility for some creative uses. I'm also thinking that the ZX Evolution board could go very nicely inside the SVI case.

Edit: A word of warning! I have suggested that building keyboard combinations (Backspace, cursor keys, etc.) would be a simple matter of connecting the key to the relevant inputs on the motherboard. However, it does not seem to be quite as straightforward. The Spectrum+ and Spectrum 128 keyboards, which have these kind of combinations, use a three-layered keyboard membrane. The functions of the membrane are not easy to replicate with wires. I may have ruined the ULA chip of my Spectrum by messing around with a poorly built "Delete" key circuit, although the cause is not absolutely certain. I need to learn more before I can suggest a solution, that is, if it is possible at all - the Spectrum+/128 solution is mechanical. I still think it should be pretty safe to create the normal Spectrum keyboard circuit, as I have shown above, without any combination keys. Of course, in any case it makes sense to turn off the machine when inserting the connectors.