aleste 520ex colours

[arnoldemu]

I have been looking at the aleste schematics again.
I see it generates luminance so should be useable with GT64 and MM12.

However, the schematics don't give the resistor values for the conversion of digital to analogue for the colours and also for generating the luminance... so I can't emulate this correctly in Arnold yet.

Anyone help who has a real one or a hi-res photo/scan of the motherboard?

[Cpcmaniaco]

Jaime - Deepfb has one.

I will see him tomorrow and tell him about that.

[Xyphoe]

Photos here - http://aleste520.narod.ru/html/galery.html - but a bit small and probably of no use to you

*edit* its the same pics on the CPC Wiki article, apologies - not what you're looking for is it.

[Bryce]

This foto here is large enough to recognise the resistor values: http://www.cpcwiki.eu/imgs/2/2d/Deepfb-aleste-without-keyboard.jpg

Which resistors are you referring to?

Bryce.

[Bryce]

By the way, I see you added some info to the Wiki, stating that the Lum signal goes from 0 to 5V. If Amstrad adhered to the JVC S-Video Specification, then the Lum signal should be a 0 to 4V signal where <1.3V = Pure black. Although 5V wouldn't damage the monitor, just the surface of your retina

Bryce.

[arnoldemu]

By the way, I see you added some info to the Wiki, stating that the Lum signal goes from 0 to 5V. If Amstrad adhered to the JVC S-Video Specification, then the Lum signal should be a 0 to 4V signal where <1.3V = Pure black. Although 5V wouldn't damage the monitor, just the surface of your retina

Bryce.

The lum is calculated from the r,g,b using resistors, then passed through a transistor (Q102) I think. One input is 5v, other is lum. Does this adjust the signal so that it is in that range?

EDIT: It seems following this there is a resistor, so perhaps that then brings it down to 0 to 4v.

[arnoldemu]

This foto here is large enough to recognise the resistor values: http://www.cpcwiki.eu/imgs/2/2d/Deepfb-aleste-without-keyboard.jpg

Which resistors are you referring to?

Bryce.

oK there are 3 vertically together.
They are near the massive blue capacitor thing on the left side.
Look to the IC next to that (positioned vertically) and look up a cm or so. there are 3 vertically here.
near to the cylinder capacitors (greenish colour), a flat grey looking one, and some kind of orange connector thingy. On e has green on it, next to it is orangy, then another orangy one.

now, the main colour ones, well they are hidden in this picture.
they are under the chip thing that has rectangle of red and blue on it (red is some kind of capacitor).
there is a red square block thing to the left, they are under here.
they are horizontally positioned. damn.
top one seems to be greenish in colour.

The component map identifies their location, they are:

R52-R61 inclusive.

[Bryce]

Wow, I actually understood that description But alas, the resistors aren't "readable" in this picture, especially the redish coloured ones.

The massive blue thing is actually a 3.3 / 3.6V rechargeable battery like the ones used for battery backup of RAM, so obviously a mod, definitely not part of the original product. I suspect the orange block things are some sort of inductor or capacitor. The flat grey thing is probably a 1W resistor. Are the schematics available on the Wiki?

Bryce.

[arnoldemu]

Wow, I actually understood that description But alas, the resistors aren't "readable" in this picture, especially the redish coloured ones.

The massive blue thing is actually a 3.3 / 3.6V rechargeable battery like the ones used for battery backup of RAM, so obviously a mod, definitely not part of the original product. I suspect the orange block things are some sort of inductor or capacitor. The flat grey thing is probably a 1W resistor. Are the schematics available on the Wiki?

Bryce.

Yes the schematics are available.
And also the board layout, but nowhere does it say the values for the resistors

[Bryce]

What a strange schematic??? Who goes to the bother of creating an entire schematic and then doesn't bother to enter the component values???

Bryce.

[robcfg]

Thou shall not fear, my friend. I'll ask Deepfb to bring his Aleste and scan its PCB.

[Gryzor]

If you get him to mail it to me I'll make sure I'll scan and photo everything in super high-rez

[deepfb]

Hi!

Sorry for the late reply, I've been very busy these weeks.

oK there are 3 vertically together.
They are near the massive blue capacitor thing on the left side.
Look to the IC next to that (positioned vertically) and look up a cm or so. there are 3 vertically here.
near to the cylinder capacitors (greenish colour), a flat grey looking one, and some kind of orange connector thingy. On e has green on it, next to it is orangy, then another orangy one.

The green one is brown-red-red-silver, so it's a 1K2 resistor. The one in the middle has no colours on the surface, but I could read the value written under it: 6K8. Finally, the one on the right is labelled 3K3.

I have used the voltmeter on them, and the measures match with this information :-)

now, the main colour ones, well they are hidden in this picture.
they are under the chip thing that has rectangle of red and blue on it (red is some kind of capacitor).
there is a red square block thing to the left, they are under here.
they are horizontally positioned. damn.
top one seems to be greenish in colour.

They are, from top to down:
- Orange-blue-brown-gold (360 Ohms)
- Red-red-brown-gold (220 Ohms)
- Orange-blue-brown-gold (360 Ohms)
  - Red-red-brown-gold (220 Ohms)
  - Orange-blue-brown-gold (360 Ohms)
  - Red-red-brown-gold (220 Ohms)

Again, I've tested them and the measures match with the colours :-D
This is a pic of them:



Thanks for including this awesome computer on Arnold! :-)