Séquence nostalgie : Amiga 1200; Solectron Bordeaux

C'était au début des années 90, en fait l'Amiga 1200 est sorti en octobre 1992. Une partie de ces machines était assemblée chez Solectron près de Bordeaux, il y a 25 ans, en 1993.

Je n'ai jamais possédé une telle machine. Tout juste ais-je eu l'occasion d'admirer un Amiga 1000 à l'époque ou un ami plus fortuné que moi s'en était acheté un exemplaire en 1986. Les démos qu'il m'en avait fait m'avaient totalement stupéfait. Il est vrai que dans le monde professionnel, mis à part l'univers Mac hors de prix et donc peu fréquent, le 286 sous DOS 3.30 régnait en maître :

Evidemment, le côté 'sexy' de l'interface ne saute pas vraiment aux yeux. Alors quand on se retrouve confronté à ça : 

Forcément....Mais bon, c'était il y a 25 ans....

And the dream comes true!

I was fascinated by synthesizers as soon as I discovered these instruments. For me it was the Poly 61, described in a specialized journal of the time :

The First Synth I was abble to buy was the JX-3P :

And my first concert (demo) by Francis Rimbert at Auray, a very small city in France, in 1984 I think because the TR909  was present :

For me, it was juste incredible : the TRs, The Jupiter 8, Junos sequencers and others (a small Teddy bear). I thought then, that one day I would make my own synth. But it was also the end of the Curtis era and these CEMs. So it really seemed very difficult to just create a synth. Of course, today the technical resources are considerably democratized. But it's still a big job for a single person to develop a machine.

However, it is again possible to find some CEM clone. And voilà :

My new toys for the next few weeks/months.

SY99

New baby at home : 

Fully functionnal.

Some switchs need top be replaced as well as the backlighting of the display.
Nothing difficult.

Yep!

SRAM select command Ver 1.0

The circuit for the selection of the sixteen SRAM bank is done.

This system is able to select the sixteen 2Kb equivalent space memory of my auto-saved memory :

To reach this goal, I used a totally new microcontroller for me and Chinees brand. This microcontroller is unlike any of those known in Europe or the USA. But I like testing new solutions... To work with this new I.C., there is an emulator that can be used to prototype the concept :

As usual, when the program 'looks' good, it's time to burn the software into the microcontroller. This microcontroller is not in-circuit programmable and does not offer the in-circuit emulation. It's a little limitation to its use, especially for complex systems. But the emulator supports the real-time mode. In the same way, the programmer does not allow to directly burn the type of microcontroller used, it is necessary to make a small assembly :

But, again, it works very well :

Once the program is written into the microcontroller, it remains only to solder it on the final board and to test the final assembly :

The system works perfectly and I was able to test the access to all the banks in the memory, thanks to the use of the test mode of the Mini-Pro 'universal' programmer.

Now, the next step is to install the complete system into the JX-8P, for example...

M.I.D.I. MERGE 'HUB'.

An other project in progress :

M.I.D.I. MERGE HUB

• Easy to use two input merged ports towards six output ports.
• One output replica port for one of the input port. 
• Small form factor with 3,5mm jack connectors.
• Single USB mini power port.

M.I.D.I. to CV/GATE

An other project in progress :

M.I.D.I. to CV/GATE interface

• M.I.D.I. channels : 1 to 8 OR 9 to 16.
• GATE : 5V.
• CV : 4 x (0V to 5V) and 4 x (0V to 10V).
• CONNECTOR : 3,5mm jacks.

SRAM select command.

My system of SRAM bank selection in on the way...

This system selects one of the memory banks installed inside a synthesizer. It will remain outside the synthesizer and will be connected to the internal memory using a connector placed on the instrument case.

In addition, a MIDI connection will allow the automatic selection of the bank, in relation to the desired patch. So it will not be necessary to modify the synthesizer motherboard in any way.

This system makes it possible to manually modify the memory bank, as well as the MIDI channel for receiving the MIDI bank change information. The MIDI channel and the number of the last bank used will be saved.

this system should also be a better bank change solution for my Prophet VS, compared to the previous system :