mercredi 20 janvier 2021

PLC PACK for the Colour Maximite 2

After working for a while on the development of the vintage PAL reader for the Color Maximite II micro-computer, I went on to test the PLC type expansion board.

This expansion is equipped with
  • - 3 opto-isolated logic inputs.
  • - 3 relay outputs
  • - 2 analog inputs 10V
  • - 1 DS18B20 input
  • - 1 TTL serial communication port
  • - 1 RS485 serial communication port (optional)
The tests are almost finished :

In this picture, I have connected two control/command screens of different type.

I connected a Nextion screen whose communication takes place by TTL serial link and thanks to a very simple exchange protocol in the form of ASCII frames.

I also connected a second screen which is used in PLC systems and which communicates in Modbus ASCII through an RS485 link. This screen is used to test the control of the outputs of the PLC board.

The program in Basic uses an interrupt to manage the system timer, another interrupt to manage the triggering by the logic inputs of the board and finally a last IRQ for communication with the industrial screen.

Everything works smoothly and very responsively.

I am very impressed by the efficiency of this system, as well as by the basic interpreter which allows to manage without problem all these different interfaces.

The original Colour Maximite 2, an ARM7 based micro-computer :

Soon a more detailed description on

samedi 9 janvier 2021

Vintage PAL reader.

How to find the equations of old PALs that we find in vintage machines?

With this PAL / GAL reader:

More info here.

mardi 8 décembre 2020

A Drumulator in a FPGA?

After getting back to working with FPGAs for a few weeks, I took a first study of the Drumulator processor core to implement it in a Terasic DE2-70 board:

Obviously, shown like this, it is neither very sexy nor impressive. But, thanks to the keyboard with serial link previously made, I was finally able to observe for the first time the operation of the heart of the machine. 

More informations here :

samedi 5 décembre 2020

uPF--2? In fact, an uPF--1 in FPGA!

The concept of the Z80 development kit based on an FPGA board is validated :

more info here:

lundi 23 novembre 2020

Reader of Vintage PAL (next)

That's it, the reader of vintage PAL is functional. It can read old 20-pin PALs found in vintage synthesizers or computers. This makes it possible to find the equations of these programmable circuits and thus to program more modern components such as replacement GALs, with a GAL programmer like the MiniPro.

The PAL reader.

The Mini Pro programmer.

More info here: Reader of vintage PAL

lundi 2 novembre 2020

Power Supply for what you want....

A few weeks ago, I presented on this blog the development of a power supply mainly intended to replace those of the old machines.

After receiving virtually all components and performing the first tests, this power supply is working properly. The first measurements show that it is also very efficient and hardly heats up.

More info here: Synth Lan