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: https://sillycony.blogspot.com/

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

The new three output PSU is validated.

VALIDATED! 

More information at : The new three output PSU is validated.

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

PAL READER for the Colour Maximite 2

In the past, I have had to troubleshoot some Drumulator and more recently SP12. During this process it is necessary to understand the logical functioning of the machines. The problem is that among all the logic circuits, there is the presence of old PALs. These pals must be read to determine their logical equations. Unfortunately, there is no cheap pal reader to do this.

MiniPro TL866

Usually, a component programmer/reader like the MiniPro is sufficient to perform the read operation. However, this Minipro cannot read old PALs. The simplest solution is therefore to wire a breadboard connected to an Arduino like the Arduino Mega to perform the operation. 

Arduino Mega.

This is what I did to retrieve the PAL informations from the Drumulators. To do well, it would have been necessary to create a printed circuit board allowing an easy re-use of this system. However, I don't find the Arduino system to be particularly relevant for this type of application, especially for reading / writing files.

As I have just made a Color Maximite 2 computer, and this system includes all the elements to operate in total autonomy, I decided to create a PAL reading interface for this system : 

This board is really very simple. Once completed, it will remain to write the reading procedure program in Basic. What inspired me to use this computer is that with a processor which operates at more than 400MHz, the execution of programs written in Basic is really very fast.

In addition, adapting a program written in basic is very fast. On this system which has an integrated editor, a USB keyboard input and a VGA output, this operation is done without using a PC equipped with a compiler and programming software. It is really much more convenient.

As far as I'm concerned, I made the version of Maximite 2 presented on the picture above. This version is not very 'practical' to make because it requires a processor module available from Waveshare. Other sites offer a version where the processor is soldered directly to the motherboard. I also decided to do by myself some printed circuits board made of this version because it seems that, due to a strong demand for this Color Maximite 2, there are no more available on the 'market'.

Colour Maximite 2 Main board version without the Waveshare module.

You can find more information about the Color Maximite 2 on this site: https://geoffg.net/CMM2

EPS16+ update.

About two years ago, I was able to acquire a basic EPS16 + for around $150 in perfect condition. However, as it stands, the EPS16 + is not very interesting to use. 

The system and instruments are loaded using the floppy disk drive which, apart from being a slow loading system, tends to degrade over time and then break down.

The machine comes with 1MBytes of memory, which is not very important since it allows just 11s of sound at the maximum sampling rate. A little limited for the simultaneous loading of several instruments.

http://www.vintagesynth.com/

The idea, after having acquired this EPS16 +, was to try to upgrade it. However, the ensoniq company has not existed for a long time. So, how to find the necessary expansions, knowing that it is very difficult to find now.

Fortunately, there are people (like me ;-) ) who make such expansions.

Regarding the 'external' of 1MBytes and the SCSI interface, I turned to ZiN Circuits :

These boards are very easy to install and although I have not yet tested the SCSI part, the 1MByte memory is instantly recognized. 

This allowed me to test the multi-timbral capabilities of the machine under good conditions. On this occasion, it was easy for me to realize that loading several instruments using the original floppy disk drive was not a very reliable solution. I have had several reading problems and it took me a long time to do this successfully. 

So, time to switch to the HxC floppy drive emulator :

Once this floppy drive emulator was installed it was much easier not only to load the instruments but also to save my work. In addition, the system was loaded now without any reading problem.

But, all these operations were always done in a slow way since starting from, and towards what remains a floppy drive. 

There was an interesting expansion for the EPS16 + which consisted of a Flash Bank. In fact, a set of non-volatile flash chips providing a total of 1MBytes of storage for the system as well as a few 'favorite' instruments. 

The very big advantage of this Flash Bank is that the loading of the system becomes automatic after switching on the EPS. The loading of the instruments which are saved there is done this time instantly. In short: a must have!

I contacted Tom Virostek from http://www.straylightengineering.com/ which offers this board:

http://www.straylightengineering.com/

I installed this expansionvery recently, in fact, I have some photos taken during the operations.

First, the board must be mounted on the display board. The front panel already has the 'holes' which will receive the mounting elements of the board.

The expansion board holes are a bit too small (3mm it seems to me) and need to be enlarged to 4mm. Once this modification has been made, the installation of the board and the ribbon cable is carried out without problem. You can download the assembly guide directly from Tom's website : Ensoniq-Flashbank-FB-1-FB-2-Install.pdf

The red board under the Flash Bank ribbon cable is the SCSI board. Under this red board, there is therefore the 1MByte memory expansion board. Both of these were installed previously, as noted above. 

Once all the boards are installed inside the EPS, it looks like this :

Some pictures of the display taken after installation :

- 1- Formatting the Flash Bank.

- 2 - Insert the OS disk. In fact, choose the system file from the floppy drive emulator.

- 3 - Transfert the OS to internal RAM.

- 4 - After this opération, the system is copied from RAM to the Flash Bank and it's done.

Once these four operations have been carried out, the System is written in Flash. When the EPS is powered on, and having taken care to have removed any system disk first, the EPS will automatically search if it finds its system in Flash and, as is the case now, loads it directly from the Flash.

Therefore, the loading of the system is almost immediate. It really changes the life and the way to use this EPS16 +. 

Loading and saving instruments with this flash is also very fast. The only constraint is that once the system is written on it, there is approximately 1.5MBytes available. It's not huge, but it allows you to save the few favorite instruments of the moment.

You can download the user manual for this Flash Bank from the TOM website: EPS-16-Flashbank-Manual.pdf.

An absolutely essential feature to install in this machine!

3 output PSU.

Sometimes it happens that the power supplies of some machines need to be replaced. And sometimes I can't find the ones that suit my needs in stores or on specialized sites. So I developed my personal version.

I added some extra features that are not usually found and that can be very useful. Troubleshooting a few Drumulators and other SP12s proved this to me. 

It had been a long time since I decided to create this type of PSU. But between the initial idea and the realization of the concept, it can sometimes pass some time.

This PSU should be able to deliver 2A on each output. This is what I will have to check when the prototype will be made :