Jagot & Leon Interface Cards

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Interface cards from Jagot & Leon.


Review from cpcrulez / RP Spiegel

The best known feature of micro-computers is their interactivity, that is to say, their ability to establish a permanent dialogue between the computer and the user through the communication set-screen keyboard. But, attractive and friendly it is, this feature operates only small part of the very great potential of a micro-computer. The user can find any other interest in his machine if it is not satisfied not to reply by posting messages, but captures some physical phenomena and then managed to order actions dependent on these phenomena. Being able to "talk" to a computer with the outside world, in other words allow him to control reactions to certain events, requires him to have cards authorizing the apprehension of external events and to "make decisions" related to events.

The company and Leon & Jagot manufactures and markets a complete line of cards designed to enable such communication. To perform the tests that follow, the company has taken the following cards:

  • E101 Card Conversion Analog / Digital 8-channel multiplexed.
  • E102 Card Input / Output / Timer.
  • E103 Map Conversion Digital / Analog 2 channels.
  • E105 to four digital outputs and four outlets 220 volts. In addition to these maps, we had the rack and backplane to allow the simultaneous use of multiple extensions.

The Rack Backplane

The rack consists of a wooden box inside which slides are drawn to the different programming interfaces. It contains a backplane on which are fixed connectors are plugged in which the various interfaces. You can still use four interfaces with the same backplane. All will be connected to the CPC through a flexible cable. Let's face it, all, even if practical, which has several cards, is not the most beautiful effect. On an aesthetic level first. The choice of wood as a constituent of the rack is really "do it yourself", and it seems to be straight out of the radius cutting wood from a store. A plastic case would surely have had a different aesthetic, but this choice was made for price reasons.

Regarding all CPC-Rack, it is much better. I hope there connection cables longer than I had. If not, I repeat the same comment I made to the map of M64 PHOENIX CORE "hello visibility. Here's how this all:

  • Your CPC,
  • Connected to the rear of the CPC, the cable between the rack, CPU, and floppy drive,
  • In the middle of the cable, the interface of the unit disk (and possibly other interfaces),
  • At the end of the cable, the rack containing the interfaces and Leon Jagot. So you have between your CPU and monitor your CPC, rack and various interfaces, which will cover the lower part of the screen. It is true that you can see this part you erect in your seat or buying extension cables for connecting the CPU to the screen. But it is also true that this is not always the buyer to make an effort and that hardware designers may from time to time I will look into the practicality of what they offer I, which does not be very complicated.

Interface cards

Before examining each map in more detail, first, here is what is common to all these interfaces.


The realization seems neat maps and driving a hard epoxy, double-sided PCB. The components used are known for their reliability. It should be noted that contacts between the interfaces and connectors of the backplane or cable connection is not the best quality. By that, I want to say that the wear of these contacts is very fast. I do not want to show that the traces of wear visible on the maps I had in my possession, maps, to the extent where they came directly from the manufacturer, had probably not been the subject of intensive use. Regarding the maps with terminals, it will be necessary to make the desired connections on the terminal before boarding the interface in the rack. This is altogether logical, but rather, given what I wrote above regarding the quality of contacts, do not make too many experiments before final assembly.

The address decoding is located on each card, so you can easily change when you use two interfaces of the same nature. However, if you use more than two identical cards, you should apply the change to Jagot and Leon.


The documentation provided with each card is inadequate and poorly designed, even if it is logical to assume that one who acquires such interfaces has minimal knowledge regarding the use of orders BASIC INP and OUT (or IN and OUT for one who works in Z80 assembler).

If the examples and explanations provided make a significant familiarity with the use of interfaces, even when they sin by a lack of specifics and details (eg map EL05). This documentation has been made by the designers of the cards, that is to say by people who owned them thoroughly. Alas, they forgot that some users of their cards might need additional information. (See in particular the E105 card). I regret also the quality of implementation and support of this documentation. It is really too "poly-cop course, that is to say, very traditional and very sloppy. The explanatory diagrams are very poorly made. For the price at which these interfaces are available, it would surely have been possible to make an effort in that direction. So when the French designers of equipment will they have to take seriously their customers and offer them references to the quality of those found on English material? (There are few manufacturers that offer French literature worthy of the name that resembles anything but a rough draft quickly corrected and photocopied).

Using maps

In all cases, it is very simple. It suffices to use the cards to send or receive a byte (whose address you provided is of course the documentation) in the address space of the CPC. Ease of use allows you, while the assembly is preferable for performance reasons, to use these interfaces using Basic programs.

E103 and E101 cards

Able to get the computer processing of natural phenomena that are external, needs to convert binary numbers understood by the machine the values of the treated phenomena (eg temperature). The order of reactions to the values of processed events prompted the reverse conversion. The E101 card, card or digital-analog conversion to convert voltages between 0 and 5 volt digital outputs between 0 and 255 so that you can deal with your CPC. Use this map does not pose any particular problem Qe and operation have tried measuring voltage supplied by electric batteries and a voltage converter) seemed correct. Again, I regret that the documentation is not more complete as regards the calibration of the map. E103 map is a map of analog-digital conversion. It allows you to convert a number between 0 and 255 calculated by your CPC voltage between 0 and 2.56 volts on the map. With this card, no problem. By measuring the voltages obtained a metrix output depending on the value sent by the CPC, I scored quite consistent with what is announced. I also stated (but I did not tried), it is possible to obtain this card output voltages up to 10 volts.

E105 map

It is a card offering:

  • Four digital outputs 0 / 5 volts
  • Four outputs 220 volts.

Power circuits at 220 volts and low voltage circuits of your computer are isolated from each other through the use of optocouplers for isolation of about 2000 volts.

The test conducted on this. Map has asked him either, no particular problem. Lechenillard mounted according to the instruction manual worked well, and voltage measurements made between the logic outputs and the mass have been well the, values announced. Use of this card is very simple. But even if it the user manual provides all the necessary information. This is not the case. So let me point out that the bits of the byte sent to the address & F9F0 control the digital outputs, and significant bits outputs 220 volts.

E102 map

There is a map entrée-sortie/timer. It can manage twenty-four input / output and three programmable timers. This card uses the classic 8255 and 8253 home INTEL. With the E105 card, this should be one of the most used of the lot. It allows to control all kinds of items outside the computer (relays, etc..).


For those who want to try to do more with their AMSTRAD, especially engaging in robotics, and Leon Jagot this, with this set of cards, a complete set of interfaces, opening new horizons to CPCs. The care taken in their implementation, reliability suggest that the components used and the possibility to use it easily from the Basic can consider applications if not strictly professional, at least the high level of personal applications (search for issuers, regulation of heating, etc..) and other than endless managements account or files that are so far the only personal applications (except games and emulations MINITEL) offered to users of microcomputers.

RP Spiegel, Cahiers de l'Amstrad 3, April / May 1986 - http://cpcrulez.fr