mikela@tekig3.LEN.TEK.COM (Mike Larson) (08/18/89)
[] I recently connected my A1000 to an Intec multiscan moniter (this moniter is also marketed under the brand name Samsung) using an appropriate cable (i.e. analog R,G,B, HSYNC, VSYNC, and 4 GND lines.) The Intec is a VGA-compatible moniter that accepts analog or TTL-level input. This multiscan performed flawlessly when the Amiga was displaying a non-interlaced screen. An interlaced screen, however, showed an incredible amount of flicker, much worse than my 1080. Upon closer inspection of the CRT I realized that the odd and even frames were being SUPERIMPOSED on each other rather than being displaced by half of a scan line. Question: do any multiscan moniters correctly handle interlace, or is it just this particular brand that fails? Or am I doing something else wrong? The reason I'd like to get a multiscan is that I have to let go of my 1080, and I want a moniter that will work with my A1000 now and with any future Amiga I get that may have a higher-scanrate output (like a flicker-fixer or the enhanced chipset.) Thanks, Mike Larson mikela@tekig3.LEN.TEK.COM
aduncan@rhea.trl.oz (Allan Duncan) (08/18/89)
From article by mikela@tekig3.LEN.TEK.COM (Mike Larson): > I recently connected my A1000 to an Intec multiscan moniter (this moniter > This multiscan performed flawlessly when the Amiga was displaying a > non-interlaced screen. > An interlaced screen, however, showed an incredible amount of flicker, much > worse than my 1080. Upon closer inspection of the CRT I realized that > the odd and even frames were being SUPERIMPOSED on each other rather > than being displaced by half of a scan line. If the scan-lines were over the corresponding ones from the previous field, you would not expect to get worse flicker, rather you have an approximation of non-interlace. If, however, there was a substantial vertical offset between the odd and even fields, severe flicker would appear. If you had been feeding composite sync to the monitor (as used by the 1080) there could have been interaction with the complicated vertical sync region (designed for cheap valve sync circuits when I was but a lad). All I can offer is that the unit is iffy, OR it has significantly brighter output. Flicker is strongly brightness dependant. -- Allan Duncan ACSnet aduncan@rhea.trl.oz ARPA aduncan%rhea.trl.oz@uunet.uu.net UUCP {uunet,hplabs,ukc}!munnari!rhea.trl.oz!aduncan Telecom Research Labs, PO Box 249, Clayton, Victoria, 3168, Australia.
thomas@cbmvax.UUCP (Linda Thomas - QA) (08/21/89)
In article <654@rhea.trl.oz> aduncan@rhea.trl.oz (Allan Duncan) writes: > From article by mikela@tekig3.LEN.TEK.COM (Mike Larson): > > I recently connected my A1000 to an Intec multiscan moniter (this moniter > > > This multiscan performed flawlessly when the Amiga was displaying a > > non-interlaced screen. > > An interlaced screen, however, showed an incredible amount of flicker, much > > worse than my 1080. Upon closer inspection of the CRT I realized that > > the odd and even frames were being SUPERIMPOSED on each other rather > > than being displaced by half of a scan line. > > If the scan-lines were over the corresponding ones from the previous > field, you would not expect to get worse flicker, rather you have an > approximation of non-interlace. If, however, there was a substantial > vertical offset between the odd and even fields, severe flicker would > appear. If you had been feeding composite sync to the monitor (as used > by the 1080) there could have been interaction with the complicated > vertical sync region (designed for cheap valve sync circuits when I was > but a lad). All I can offer is that the unit is iffy, OR it has > significantly brighter output. Flicker is strongly brightness > dependant. > Some multi-sync monitors don't know how to interpret an interlaced signal. They don't know which frame (or field, I always get the two mixed up) is even and which is odd. What happens is that the scan lines may not get drawn in the same place from frame to frame (it's odd once, then even). This does cause an incredible amount of flicker and often makes text nearly illegible. -- Linda Thomas, Commodore Amiga Test Engineering UUCP ...{allegra,rutgers}!cbmvax!thomas
jms@tardis.Tymnet.COM (Joe Smith) (08/22/89)
In article <654@rhea.trl.oz> aduncan@rhea.trl.oz (Allan Duncan) writes: >.... If you had been feeding composite sync to the monitor (as used >by the 1080) there could have been interaction with the complicated >vertical sync region (designed for cheap valve sync circuits when I was >but a lad). All I can offer is that the unit is iffy, OR it has >significantly brighter output. Flicker is strongly brightness dependant. The problem as originally reported is probably a design in the monitor. Some multisync monitors with RGB input can handle 262 lines in 1/60 second yet refuse to do 262.5 lines per frame. The place where Augnet meets has the opposite problem. The large screen monitor there has a composite input that gets all upset if the incoming signal is not interlaced. They have to use SetLace (or LaceTogl) to force the interlace signal when showing 640x200 or 320x200 screens. -- Joe Smith (408)922-6220 | SMTP: JMS@F74.TYMNET.COM or jms@tymix.tymnet.com McDonnell Douglas FSCO | UUCP: ...!{ames,pyramid}!oliveb!tymix!tardis!jms PO Box 49019, MS-D21 | PDP-10 support: My car's license plate is "POPJ P," San Jose, CA 95161-9019 | narrator.device: "I didn't say that, my Amiga did!"
esker@abaa.uucp (Lawrence Esker) (08/22/89)
In article <7718@cbmvax.UUCP> thomas@cbmvax.UUCP (Linda Thomas - QA) writes: >In article <654@rhea.trl.oz> aduncan@rhea.trl.oz (Allan Duncan) writes: >> From article by mikela@tekig3.LEN.TEK.COM (Mike Larson): >>> An interlaced screen, however, showed an incredible amount of flicker, much > >Some multi-sync monitors don't know how to interpret an interlaced signal... This seems to be a common thread, oft repeated. Anyone out there have muti-sync monitors that do work with interlace? I will collect a summary and post it for the monthly introduction. Please send email. Since ECS is about to happen, we all need to know so we don't get burned. -- ---------- Lawrence W. Esker ---------- Modern Amish: Thou shalt not need any computer that is not IBM compatible. UseNet Smart: esker@abaa.uucp or abaa!esker@itivax.iti.org UseNet Other: __!uunet!mimsy!rutgers!citi!itivax!abaa!esker Nothing left to do but :-) ;-) ;-D