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80COLMON.TXT
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2006-10-19
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PUBLISHED IN LIMA NEWSLETTER MARCH 1989
^^^^^^ COLOR AND MONOCHROME MONITORS FOR USE IN
^^^^^80 COLUMN WORK WITH 99/4a AND GENEVE SYSTEMS
EDITOR'S NOTES: by Charles Good. The following
article and accompanying chart was prepared by DIJIT
SYSTEMS to describe features of the limited number of color
monitors that can be used with the Geneve computer, the
DIJIT APVC card, and the Mechatronics 80 column peripheral
(it doesn't go in the PE box, so I don't call it a card).
All three of these use the same video chip. Although the
article was prepared DIJIT for users of their product, it
seems to me to be a good objective comparison of these
color monitors. To view in color with any of these three
hardware devices you can't use just any RGB monitor. You
must use an "analog RGB monitor" and your choices are
limited. You have to look a long time before you find any
of the below described monitors in Computer Shopper
advertisments. The key words to look for when shopping for
GENEVE/AVPC compatible monitors in stores or in
advertisments are "AMEGA" or "RGB ANALOG". Any monitor
compatible with the Amega should work.
You can, of course, also use an 80 column rated high
resolution monochrome monitor with any of these hardware
devices. Almost any monochrome monitor will work, and they
usually cost well under $100. Based on my personal in
store comparisons, the resolution of almost any 80 column
rated monochrome monitor is BETTER than what you can get
with a .42 dot pitch Amega compatible color monitor. When
I configure FUNNELWEB for color combination F1 (white on
black), the bright green text displayed on my monochrome
monitor with FUNNELWEB's 80 column editor looks really
great. Colors other than black or white show up as various
shades of green. I have found no software that is rendered
not usable because of the way "colors" are displayed on my
monochrome monitor, although sometimes the monitor's
"color" display leaves alot to be desired.
The "list price" for color monitors shown in the chart
below should only be used as a guide, as discounts are
often available. For example, DIJIT sells the Magnavox
8CM515 for $295 plus shipping.
------------------------------------------------------
DIJIT Systems
APPLICATION NOTE #1
Rev. 4/10/88
^^^^^^^^^^^80 COLUMN ANALOG RGB MONITORS
High resolution analog RGB monitors have been used in industry for
a number of years in computer aided design and professional graphics
work stations that make those spectacular animated sequences seen on
television. These monitors generally have 19 inch picture tubes and
are capable of displaying up to 1280 x 1024 pixels. Their costs range
upwards from $2500.
The need for analog RGB monitors in the personal computer field
has emerged in the last couple of years. The Amiga and Atari ST have
brought with them scaled down graphics capabilities not unlike that of
their more expensive cousins. The plethora of graphics cards for the
IBM-PC type computer has given rise to the "multisync" monitors with
both digital and analog RGB inputs. Even in the world of the TI-99/4A,
the DIJIT Systems RGB Conversion Kit requires an analog RGB monitor to
display the shades of color generated. And the AVPC as well as other
V9938 based video cards require analog RGB monitors to display the
palette of 512 colors they are capable of generating.
The accompanying chart was prepared as an aid in selecting an 80
column, analog RGB computer monitor. It omits two of the categories
mentioned above, namely the industrial type, whose cost makes it
inappropriate for the TI market (unless you can find a used or surplus
one at a bargain price), and the "multisync" or "multiscan" types. A
good review of the latter can be found in the February 1988 issue of
Byte Magazine. The chart contains the best information available to us
and will be revised periodically. As you can see, there is not an
extensive selection.
All of the below monitors comform to the EIA RS-343A standard
requiring 0.7 volts p-p of video across 75 ohms input impedance. This
signal level is the same as required by TV monitors and VCRs and is a
worldwide standard. For simplicity we indicate 1 volt. The
synchronizing signals required are combined (composite) horizontal and
vertical sync having a negative sense at 0.3 volts p-p. The sync is on
a line separate from the video.
Two factors effect resolution. They are the dot pitch of the
physical pixels on the face of the picture tube and the video
bandwidth. The coarsest dot pitch with which you can comfortably view
80 column text on a 14 inch diagonal screen is 0.42mm, making the
Thomson 4120 a marginal 80 column performer. Ten Megahertz is the
minimum video bandwidth required to pass the high frequency components
necessary for sharp edges on alpha-numeric characters. High quality
monitors have a bandpass of 18MHz and up.
In general, the higher the resolution, the higher the price. It
all boils down to what you are comfortable with and what you are
willing to pay. You are the final judge. The list prices shown are
over a year old and are given for comparison only. Most monitors can
be bought at substantial discounts by prudent buyers.
ANALOG RGB
________________________________________________________________________________
! ! LIST !SCREEN! DOT !HORIZ.!BAND- !VIDEO ! SYNCHRONIZATION >
! MODEL ! PRICE ! SIZE ! PITCH !PIXELS!WIDTH !INPUT !V !H !V+H! OTHER >
!__________!_______!______!_______!______!______!______!__!__!___!_____________>
! ! ! ! ! ! ! ! ! ! ! >
!AMIGA 1080! 495 ! 13" ! .42mm ! 666 !>10MHz!1V p-p!Y !Y ! Y ! >
! ! ! ! TRIAD ! ! !75 ohm! ! ! ! >
!__________!_______!______!_______!______!______!______!__!__!___!_____________>
! ! ! ! ! ! ! ! ! ! !REQUIRES >
!ATARI ! 400 ! 12" ! .38mm ! 640 ! !1V p-p!Y !Y ! N !SYNC >
!SC 1224 ! ! ! TRIAD ! ! !75 ohm! ! ! !SEPARATOR >
!__________!_______!______!_______!______!______!______!__!__!___!_____________>
! MAGNAVOX ! ! ! ! ! ! ! ! ! ! >
! 8CM515 ! 599 ! 14" ! .42mm ! 666 ! 14MHz!1V P-P!Y !Y ! Y ! >
! 8CM536 ! 749 ! 14" ! .31mm ! 800 ! !75 ohm!Y !Y ! Y ! >
!__________!_______!______!_______!______!______!______!__!__!___!_____________>
! SONY ! ! ! ! ! ! ! ! ! ! >
! CDP-9000 ! 600 ! 10" ! .25mm ! 640 ! 20MHz! !Y !Y ! Y ! >
! CDP-1201 ! 650 ! 13" ! .25mm ! 800 ! 20MHz!1V p-p!Y !Y ! Y ! >
!KV-1311CR ! 630 ! 13" ! .37mm ! 640 ! 10MHz!75 ohm!N !N ! Y ! >
! ! ! ! STRIPE! ! ! ! ! ! ! >
!__________!_______!______!_______!______!______!______!__!__!___!_____________>
! TEKNIKA ! ! ! ! ! ! ! ! ! ! >
! MJ-305 ! 549 ! 13" ! .41mm ! 650 ! 16MHz!1V p-p!Y !Y ! Y ! >
!__________!_______!______!_______!______!______!______!__!__!___!_____________>
! THOMSON ! ! ! ! ! ! ! ! ! ! >
! 4120 ! 399 ! 14" ! .51mm ! 560 ! 12MHz!1V p-p!Y !Y ! Y ! >
! ! ! ! STRIPE! ! ! ! ! ! ! >
! 4160 ! ! 14" ! .38mm ! 640 ! ! ! ! ! ! >
! ! ! ! STRIPE! ! 12MHz!1V p-p!Y !Y ! Y ! >
!__________!_______!______!_______!______!______!______!__!__!___!_____________>
80 COLUMN MONITORS DIJIT Systems 4/88
________________________________________________________________________________
> ! ! !
>AUDIO!OTHER FEATURES! COMMENTS !
>_____!______________!_________________________________________________________!
> ! ! AMIGA MONITOR. TWO VENDORS CURRENTLY SUPPLY COMMODORE - !
> YES ! ! TEKNIKA AND TOSHIBA. !
> ! ! !
>_____!______________!_________________________________________________________!
> ! ! ATARI ST MONITOR. HAS PROPRIETARY 13 PIN PLUG NOT !
> YES ! ! READILY AVAILABLE. REQUIRES A SYNC SEPARATOR TO SUPPLY !
> ! ! SEPARATE VERTICAL SYNC. !
>_____!______________!_________________________________________________________!
> ! ! !
> YES ! RGBI/ANALOG ! CURRENT MODELS. HAVE LOTS OF FEATURES. !
> YES ! RGBI/ANALOG ! !
>_____!______________!_________________________________________________________!
> ! ! !
> NO ! RGBI/ANALOG ! !
> NO ! RGBI/ANALOG ! !
> YES ! TV, COMPOSITE! REQUIRES 34 PIN CONNECTOR AND EXTERNALLY SUPPLIED +5V !
> ! VIDEO, RGBI ! TO ACTIVATE ANALOG VIDEO AND AUDIO INPUT. !
>_____!______________!_________________________________________________________!
> ! ! TEKNIKA IS A SUBSIDIARY OF FUJITSU. THIS MONITOR HAS NO !
> NO ! RGBI/ANALOG ! AUDIO AND REQUIRES AN EXTERNAL SPEAKER-AMPLIFIER !
>_____!______________!_________________________________________________________!
> ! ! THOMSON IS A FRENCH CONGLOMERATE. !
> YES ! COMPOSITE, ! THIS IS A MARGINAL 80 COLUMN MONITOR. !
> ! RGBI ! !
> YES ! COMPOSITE, ! SAME MONITOR, HIGHER RESOLUTION PICTURE TUBE. !
> ! RGBI ! !
>_____!______________!_________________________________________________________!