home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
ftp.whtech.com
/
ftp.whtech.com.tar
/
ftp.whtech.com
/
Geneve
/
9640news
/
CAT01
/
MONITORS.ARK
< prev
next >
Wrap
Text File
|
2006-10-19
|
8KB
|
122 lines
?
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. They are 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 ! !
>_____!______________!_________________________________________________________!
Download complete. Turn off Capture File.