fbpx


The MIDI Forum

  Friday, 21 May 2021
  10 Replies
  1.7K Visits
0
Votes
Undo
  Subscribe
I'm new here but I have a problem to discover the hardware. I need some schematics so I can change the input for setting up the system. Can somebody tell me lokking to the photo's what king of hardware here was used?
6 months ago
·
#9056
0
Votes
Undo
The photos are not a lot of help. There's a hint these are bare boards screwed to some wood. Maybe part of an arcade games machine.

More detail needed. Pic 2 has one chip at the bottom that has a label applied, would be a help to know what the label says. This may be an important chip?

Where did you get the boards from. I take it they were not in a box with any labelling?

On the basis of the info provided, could be anything.

Geoff
6 months ago
·
#9063
0
Votes
Undo
These boards are screwed in a wooden box where 3 keyboard are situated. The contacts of the keyboards are connected with the yellow wires to the board on pic-1. The eprom on pic-2 is labeled in this chip the software is situated. I hope I can read it better. The question is: Does somebody recognise these boards and give me then the brandname or typenumber so that I can look for drawings and settings of this system.
6 months ago
·
#9065
0
Votes
Undo
Are you saying that these boards are not connected to the keyboards via MIDI, but direct from the key contacts. So how does MIDI become involved.

On the basis of what I can see of the boards, thy seem quite old. As in 1980s, maybe 90s? The boards may hav.e come from something else.

Does the unit(s) you have actually work? What does it do?

Do any of the boards - check the bottoms as well for further labels - have any sort of date?

Geoff
6 months ago
·
#9067
0
Votes
Undo
The keycontacts are connected to the board on pic-1 the board of pic-1 is connected to the midicontroller of pic-2 so the keydata is sent via this midi interface to an other midicontroller where the sounds are made. Everything is working. This organ has 3 keyboards. The upper manual and the left half of the lower manual is channel 1 the middle manual and the right half is channel 2. I want to change is that the lower manual is complete channel 3. That's why I want some data of these boards. There are no further data on the other site of the boards. I was hoping somebody will recognise these boards so that I can make some contact with the designers.
6 months ago
·
#9070
0
Votes
Undo
Aha - thanks for this.

At last, starting to get some helpful information.

So, this is a single instrument, an organ, with three keyboards (as large organs do have). The system assigns part of the range to one channel, other parts to another channel. This I understand is usual for organs, I've certainly heard of this before in earlier discussions.

So, we need to focus on Organ manufacturers. Maybe even Mfgs of organ kits, aspects of this sound at least slightly 'home-made'. This is not be disparaging in any way, a significant organ would be a large beast and a home-made option would save a massive amount of cost, not least in transportation.

I had a discussion with someone else a year or two back, he was trying to sort some problems with an organ. There was a question there (among other things) regarding channels, but along the way I think I remember his saying something about the inside electronics being Roland sourced, i.e. the maker of his organ bought in the tech bits as OEM supplier from Roland. I think his organ was made by something like Rogers - I'll have to try to track down the previous discussion.

Photo 2 shows a designation on the PCB 'MIDI 8709' - this may be significant. I've checked via the web but this info does not go anywhere. I'm sure however that there must be other info on the boards, maybe hidden by wiring (or dust ?). Even any info, or designations, on the keyboards would be a help.

Geoff
6 months ago
·
#9071
0
Votes
Undo
Is the board where the sounds are made another board (not in the two pics)?

A pic of that would be useful. Chances are all the boards are from the same mfg. The (in effect) synth board is more likely to show something useful.

The chip ate the botton of pic-2 will be critical otherwise. This may not be a standard chip. Could be a PROM or even an EPROM, with unique software set into it. Anything you can read off this chip, incl the label, could be useful. careful with the label, if it's an EPROM, these are 'eraseable' (using UV Light ?) and the label may be covering a sensor..

Anything that might be a date would also be useful, Anything to narrow down when/where/who by made this.

Rodgers (Oregon ?) are the mfg I was thinking of. For a period they were in fact owned by Roland. Pre 1990 they used analog (not digital) sound generation systems. These boards certainly look pre 1990. This is looking like technology akin to the Roland MT-32 unit (I've got a Roland LAPC-I card in an old PC, and we're talking similar sorts of chips).

Geoff
6 months ago
·
#9074
0
Votes
Undo
Hi Geoff, The sounds are coming from a Roland SC-880. So it is possible that the circuitboards of the scanner and the midi interface are also comming from Roland. (Thanks for this hint) I also did some search on the internet ans did not find anything. I will open the organ again and will look under and between the wires if I can find something more. It is an Eprom I'am fore sure, and I will try to make a copy of the contense of this chip. This all can take a few day's because we have a hollyday this week :D

Mat
6 months ago
·
#9083
0
Votes
Undo
Does the Organ system output midi data to the SC-880 (Sound Canvas unit) as an external unit, or is there a SC-880 board within the organ unit?

Can you record the midi data being created?

At some point, the Channel Number is being added to the midi data. Maybe there is some ROM code involved, and you might need to change the ROM code to achieve what you want.

The usual reason for doing the split is that one sample is not enough for the whole range covered. But the SC-880 is basically GM, and I don't know if it may have 2 or more Organ samples. Maybe it does, with extra sounds available.

Plus, there's the possibility of splitting the range over different sounds anyway.

You say there are three keyboards. How does the system handle this regarding the Note Numbers? I would have thought that three keyboards could require more note numbers (key numbers) that midi would normally allow?

I'm wondering that if it's not possible to change the channel setting as you indicate, it might be worth looking at doing something on the basis of note numbers, but this would not be a help if the note numbers delivered from the keyboards overlap and the system is using the channels to differentiate. A midi file saved with played notes from different parts of the keyboard range would help a lot.

Geoff
6 months ago
·
#9091
0
Votes
Undo
Hi Geoff, The SC-880 is an external unit, not build in the organ. The only build in is the midi and a powersupply. I wil try to record the midi data and when done I will sent it ti you. Also I wil make a drawing how the 3rd keyboard is connected to the keyboardcollectorcard so then we can see how the notenumbers are made. When I can record the midi file I will tel you whichs key's were pressed at that time. Please give me some time to do this. I have to go to the owner and I have to test first at home if my midi to usb device will work propperly on my laptop.

Mat
5 months ago
·
#9213
0
Votes
Undo
Hi, Today I visited the owner of the organ. I completely opened this organ and I discovered that there were 2 midi boards installed. That's why there were gowing 2 midi cables to the SC-880. Under the boards there was no reconisable data to discover where the boards came from. I could change some wires from the keycontacts so the the owner his whishes could be made. Thank you for your interests and by reading these posts it helped me to get an idea to help the man. Thank you, Regards, Mat
  • Page :
  • 1
There are no replies made for this post yet.
Be one of the first to reply to this post!