Why did Commodore put monochrome video output on A500/A2000?

[Ral-Clan]

Just to be clear: The built in composite output of an A500 is way beyond PC land monochrome.  A500 composite is 64 shades of gray easily displayable at once from a palette of 4096 gray shades.

Well, it's really monochrome (black or white output) but each pixel can be at a different shade of intensity (luma signal amplitude I'm assuming).

[djos]

It's a shame they didnt put S-Video on the a500's and other wedge Amiga's just like the Commodore 64 had.

[bloodline]

Okay, then why didn't they put monochrome composite into the A2000 - the pro-level machine in that year's lineup?

The A500 and the A2000 were designed and build two totally separate teams, they probably didn't even know about each other. The A500 team were looking to cost reduce as much as possible and as Zac had already pointed out, with the video hybrid in the A500 you get monochrome Composite for free, so I guess they just added it as better than nothing

[Ral-Clan]

The A500 and the A2000 were designed and build two totally separate teams, they probably didn't even know about each other. The A500 team were looking to cost reduce as much as possible and as Zac had already pointed out, with the video hybrid in the A500 you get monochrome Composite for free, so I guess they just added it as better than nothing

Are you sure about that?  I know the *original* A2000 (the A2000-A) was designed by a German team, while the A500 was designed by an American team. These two teams didn't really co-operate.

But that A2000 (based more on A1000 architecture) was abandoned. The A2000-B that was actually produced was based on the A500 motherboard. And from my understanding it was developed by the same team that designed the A500. (I would like confirmation of this info).

Here is a history:
http://www.amigahistory.co.uk/a2000.html

[Iggy]

Simple answer.
Monochrome monitors were cheap and you could look at an 80 column display on a monochrome composite monitor (I had one, although I sometime switched to 64 columns for better clarity when doing word processing).
No way were you going to try that with a color composite screen.

$100 monitor vs. several hundred dollar monitor.

A no-brainer if you're primarily concerned with office apps.

[Iggy]

It's a shame they didnt put S-Video on the a500's and other wedge Amiga's just like the Commodore 64 had.

S-video output on a C64?
Where?
I don't even think they had that standard at that time.

[djos]

S-video output on a C64?
Where?
I don't even think they had that standard at that time.

Yeah the 82' model with 5-pin connector doesnt but the 83-84+ models do but there was no mini-din standard plug at the time:

http://en.wikipedia.org/wiki/S-Video#Connector_and_Cable

If you look at the 1084s monitor for example, it has chromina and Lumina inputs which is just S-Video using RCA connectors.

http://www.amiga-hardware.com/showhardware.cgi?HARDID=849

I personally use a c64 S-Video cable to connect to my Sony Bravia and the PQ is awesome.

[Lockon_15]

Indeed, A2000 was developed from German based team which took A1000 as starting point; they deleted monochrome video output (rev4.0 was last one to roll-out from that team).
US based team got involved a bit later to start B52 as a direct involvement of Rattigan's visionary acts supporting cost reduction of Amiga in general, so US -based team took over A2000 from Germans and redesigned it by using A500 components which became available in meanwhile.
As mentioned before, they spared every damn cent wherever they can find one and that literally means they omitted a single RCA socket (monochrome signal was always there at a  pin#19 of video encoder chip). A520 became a part of usual kit (unit, mouse, power supply) in Q2 1989 at the end of Rev5 assembly lifecycle, when they introduced 2 special editions.
A520 used then one of available, off-the-shelf Motorola encoders (MC1377p) which were known to be mediocre compared with true RGB signal quality. Even by modern standards, you can use either Philips SAA chip or Analog Device AD724/AD725 for much better image quality (as DIY design), but you're still lagging behind RGB. S-VIDEO was possible back at times just as A520 were introduced as a hack which involved heavy unit modification.

[Iggy]

Yeah the 82' model with 5-pin connector doesnt but the 83-84+ models do but there was no mini-din standard plug at the time:

http://en.wikipedia.org/wiki/S-Video#Connector_and_Cable

If you look at the 1084s monitor for example, it has chromina and Lumina inputs which is just S-Video using RCA connectors.

http://www.amiga-hardware.com/showhardware.cgi?HARDID=849

I personally use a c64 S-Video cable to connect to my Sony Bravia and the PQ is awesome.

That's too cool.
Much better then composite.
Until component video became common, I had a lot of devices connected with S-video cablles.

[pwermonger]

IIRC, the reason for monochrome was that not all users needed color composite. A lot of Amiga 1000 users were buying monitors. So they could save a bit on the 500 and get the 1084 monitor and be done. Those who needed color composite, were not probably not buying the 1084 and would instead buy the A520 adapter. If the 520 wasn't available immediately whenthe 500 came out, it was available shortly thereafter.

[Britelite]

Sorry, but you won't get 4096 shades of gray out of the composite output

Why not?

Because the way the monochrome composite signal is built, which is (according to the Amiga Hardware Reference Guide) 30% Red, 60% Green and 10% Blue. And with 16 levels of each color component you get 151 unique shades of grey. And considering the quality of composite output in general, I wouldn't count on all of those shades being distinguishable from each other

[gertsy]

It was not to be used... they were looking ahead to the days of jokers on ebay having old amigas that they purportedly could not test because of no RGB monitor.

10 points for the best answer...!

Btw: I just finished counting and I've counted 4094 shades of grey.  Better than any soft porn book.

[LoadWB]

Btw: I just finished counting and I've counted 4094 shades of grey.  Better than any soft porn book.

Or MacPaint gray-scale picture printed on a Commodore MPS-1250 at quad-density.

[pwermonger]

if I had to guess, which most of us can only do in this case, I would have to guess that it was one or more of the following
 
 1. Save money on the composite out, per unit that savings could add up
 2. Push people to buy new monitors instead of hook up to existing Commodore 8 bit composite monitors or TVs which makes more money
 3. those who still want color composite buy the A520 which again makes more money.

[danwood]

We're talking about Commodore, so almost certainly this...

1. It saved a few cents of production cost per machine,

[pwermonger]

The A500 and the A2000 were designed and build two totally separate teams, they probably didn't even know about each other.

They did know about each other, in fact Dave Haynie said he watched what the 500 team did (which he originally was put on) and copied a lot of it for the 2000 in his talk at VCFE 9.1. At least, the American designed one. Not the German designed one that it replaced.