Amstrad User Group

Nederlandstalig

CPC add-ons

Often found on CPC's: an external disc-drive. This often is a ready-made disc drive supplied by a more or less known supplier like for instance Vortex (a known supplier in this case). The drive shown here is a do-it-yourself 5.25" disc drive. As the drive is compatible (only the pin-layouts differ) 3.5" drives can be connected without much problems in the same way.

Worth mentioning is the modification made (to a normal connection without additional features) by the builder. The drive itself is a standard double sided 80-tracks Shugart drive with a capacity of approximately 720 kilobytes (depending on the logical format used). But besides a switch on the back (not visible in the picture) allowing you to switch the drive from 80 to 40 tracks there is another switch on the front of the cable which switches drive designation from drive B to A. In this way the drive can emulate the 3" drive A when required by the software or purpose. This is especially useful when software on 3" disc has a copy protection (usually games). This way you can make a 1:1 copy from the expensive 3" format to the cheaper 5.25" discs.

A special 3" drive for the CPC from Schneider (labeled only - it is manufactured by Amstrad). This comes with an interface especially for the first model of CPC, the CPC 464, which only features a data recorder.

A lot of the software released on 3" disc (or on other disc formats) for the 664 or 6128 can be run on the 464. Not all software, though, because the interface itself uses a little memory and this may cause a memory shortage for the software (that would run on a 664 or 6128). Besides the larger collection of software, loading from disc is a lot faster and more reliable than loading from cassettes. The advantages of random access (to a floppy disc) should not be underestimated.

Moreover, using disc drives and floppies, you can also install and run a different operating system, like (for the 464) CP/M 2.2 or a freeware derivative program like ZP/M. I really do not know whether you can do this and boot from a data recorder - I have not heard from this before and do not believe so.

The Vortex interface shown to the left (a do-it-yourself package that you have to assemble yourself) is also related to disc drives and operating systems.

This interface will allow you to run, and select between, the more powerful VDos (Vortex Disk Operating System) or the original AMSDos from Amstrad that has been implemented on all CPC's.

The particular interface shown has been expanded with several switches that determine drive-letter designation on the computer (A or B) plus the number of heads (single or double sided) and the number of tracks (40 or 80). This little device allows for a lot a connectivity and selections. Besides VDos there are competitive systems like Vortex X-DDos, MagicDos, ROMDos, RoDos and ParaDos. The latter is rumoured to be the best operating system.

It is a pity about the inevitable flash reflection in the screen and the pale colours of the picture: in reality this screen looks a lot brighter. I will try to produce a better picture in the future (when lighting conditions are better).

The colour screen is a very popular peripheral: shown here is the Schneider CTM-640 (again a labeled Amstrad). And although the abbreviation CPC (Colour Personal Computer) indicates differently, a colour monitor is not really common in The Netherlands. Here you usually see the monochrome GT-65 used as monitor. Colour screens were considerably more expensive and are therefore not really common.

Especially the gaming experience reaches a completely new dimension: you cannot even play some games (like one of my favourites shown here, QUARTERS) without the element of colour. It is possible, in theory, to connect a CPC to a television set, even using the modern SCART connector. I have tried myself and succeeded only partially. The initial display is in order but when I play a game with movement in it, the display starts scrolling from the top to the bottom. I will investigate in the future and will (try to) get back to it later.

There is not much electronics about this little device but this is nevertheless a useful add-on. The joint-venture between Amstrad and Schneider resulted in two versions of the CPC computer. The English and continental-Europe (excluding Germany) version with pcb-board as connectors and the German version that meets local certification standards with real connectors. The German Schneiders therefore feature standard Centronics connectors which causes problems with a standard Amstrad add-on: it simply will not fit.

The solution is really easy as it is only a mechanical problem: an adaptor connector as displayed in the photograph. Below is the Amstrad pcb-connector, at the top the Centronics male connector as used by Schneider.

Besides functioning as an adapter for different connectors, this device is also useful when it comes to bridging the difference in height between the computer and add-on. Especially the slim and flat CPC 6128 benefits from this as a lot of add-on devices require the 6128 to be raised, in order to connect the add-on directly to the expansion port.

The add-on shown in the picture below (just above the cassette which is, in fact, meant for the 464 not the 6128) clearly demonstrates this phenomenon. When it is fitted to the expansion port of the CPC 6128, it will stick out a few centimetres.

An add-on from dk'Tronics, a well known (in The Netherlands) manufacturer of add-ons for the CPC. This firm almost always provided the same housing with their add-ons. They provided for a solid and stable connection and also featured a break-through connector (for connecting another add-on) but were not ideal for the flat CPC 6128.

Both connections (the connection for to expansion port is, invisible on the photograph, on the bottom) are of the English variety and would require the adaptor when fitted on a German Schneider as well.

This particular expansion involves a memory expansion pack of 64 kilobytes, for the CPC 464 (hence the cassette supplied: the CPC 464 does not features a disc drive in the standard version). I believe this can be used on the later models 664 and 6128 as well, using the software supplied by dk'Tronics.

Three add-ons with peripherals connected to each other in succession, again from dk'Tronics. Going down, from the top: an interface for a light pen (with the pen and accompanying tape to the extreme right), a Silicon Disc Operating System (a bootable DOS built-into ROM, comparable to the Vortex OS already mentioned) and a Silicon Disc, a flash RAM Drive.

The photograph is a neat example of 'backpacking' also known as the Christmas tree. You can easily cause an overload when you connect too many add-ons to the expansion port (and thus the power supply). This kind of damage cannot be repaired easily or inexpensively.

You may want to consider (when you have several add-ons) to house some of the stuff inside the machine itself or to make a separate housing for peripheral equipment, possibly with a separate stabilized power supply. This will prevent power problems and provide for better and more stable connections - it looks better too!

At last, and last but not least, two examples of joysticks. Not unimportant as the CPC is often used as a games console. The model shown on the right in the picture is most commonly found with Dutch CPC's (that is, as far as I have seen). But as the 9-pin connection used on the CPC is a standard (introduced by, I believe, Atari?) there is a large selection of joystick you can choose from.

And you can always convert a joystick suitable for the 15-pins PC-game port to fit a 9-pin connector. This game port is now old fashioned itself and succeeded by the USB-connector. I guess converting a USB-connector would be possible too but have no experience in this field (yet).

To the main CPC-page.