26 Jan
2013
26 Jan
'13
4:44 p.m.
I am the originator of the thread,
I have some ECL -> TTL chips, when my arcade converter is delivered, I will
connect the chip and let you know the results.
my monitor is monochrome.
The monitors are SUN Model M19P114 part no 365-1051-01.
The pin out on the 3/140 frame buffer is
1-VIDEO+
2-GND
3-HSYNC
4-VSYNC
5-NC
6-VIDEO-
7 GND
8-GND
9-GND
VIDEO+ and VIDEO- are ECL levels , and HSYNC and VSYNC are TTL levels.
On Sat, Jan 26, 2013 at 3:04 PM, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
Why is there a
variation in the video signal? Is this comparable to the
ana=
I may be telling you what you aready know, in which case I apologise.
ECL = Emitter Coupled Logic. It's a type of logic circuitry (in the same
way that DTL and TTL are types of logic circuitry). ECL generally uses a
-ve supply rail (often -5.2V) and is higher speed that TTL, etc.
The high speed feature is probably why it was used for this video signal.
At the time, TTL logic was not fast enough, and generally could not drive
long cables well at high (for TLT) speeds. ECL could.
There were TTL <-> ECL inteface ICs (IIRC 10124 and 10125), bnt of course
the speed they could rubn at was limited by the speed on the TTL side.
You could probably use a 10125 to convert this video signal to TTL, but
whether you could be able see individual pixels clearly I don't know.
log video which varies infinitely to account for
many colors/shades? My
bat=
No, it's a 2-state digital signal. I asusme this is a 1-bit-per-pixel
system, like a lot of earleir workstations.
tery is dying, and I'm tired. No more time to
research tonight. =0A
I've foudn that runnign computers form the mains helps with this :-)
=A0=0A=
=A0I'm curious because I have an old HP color behemoth that a super-tech
wa=
s unable to get to display anything he threw at
it. Now it's a long
shot, I=
I would be _very_ spuprised if a colour monitor had ECL inputs. On the
other hand I have come across an analogue HP colour monitor (that on the
HP9836C) where hte inputs are current, rather than voltage, driven.
Do you know the model number of this HP moniotr? What is the input
connector?
Do you know if it works at all? The fact that it won't dispaly enything
might be due to a fualt i nthe monitor.
-tony