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- ***********************************************************************
- This document was originally posted on the italian Amiga Fidonet areas.
- It is on Internet by written permission of the author. This is one of
- the many contributions the Italian community gives to the Amiga users.
- ***********************************************************************
-
- The following document is Freeware, meaning that you can use it and
- distribute it freely as long as no part of this document is changed.
-
- Orginal document by Francesco Ronchi
- Translation to english by Federico Chiesa
-
- To contact the author or the translator check the addresses at the end
- of this doc.
-
- ***************************************************************************
- Note: remember this document was Made in Italy. Thank the italian Amiga
- community for this nice little trick. Give credit to the ones who earn it.
- ***************************************************************************
-
- NOTE: We are not responsible IN ANY WAY for any damage caused by (improper)
- use of the following document. If you don't know what you are doing,
- don't go on reading. If you do things the wrong way, you have a high
- chance that you will burn your monitor off. We are not responsible
- for that. Usage of this document and the information herein is all
- at your own risk.
-
- Note : we have been successfully using this trick for more than 1 year and
- it has given us no problem whatsoever, even with old monitors.
- However this was tested (directly by us) only on >1991 C= 1084S
- monitors. It should work just the same on older models like the
- 1084 and the Philips CMM8833 (or whatever that monitor is called).
- Many other people tried it and it has given them no problem, but
- in case you burn up your monitor, hey, that's your problem.
-
- ***************************************************************************
-
- What you need is the following:
-
- - Commodore 1084 or similar monitor (see below for details)
- - AGA or ECS chipsets
- - WB3.0 or maybe 2.1
- - No hardware hack/change
- - Your favourite filezapper
-
- Ok. Now:
-
- 1. Copy the Euro36 monitor driver to DEVS:Monitors.
- This monitor handles 73Hz-15Khz screens that *can* *be* *displayed*
- by the above mentioned monitor (at least our do 8) but not very well
- because part of the screen is not visible. So you have to:
-
- 2. Edit the Euro36 tooltypes to bring down the frequency to about 70-71hz.
- Trying some values with MonEd I reached for the optimal value (for my
- monitor) which is:
-
- TOTROWS = 0xdd
-
- (any other tooltypes should be left untouched). This is not enough,
- though, because the screen has the right size, but it's too 'high up'.
- Unfortunately the 'Overscan' program won't lower it, so you have to:
-
- 3. Reset so that the system recognizes the new monitor
-
- 4. Load the overscan prefs and save them the way they are already. (do not
- skip this part!)
-
- 5. Manually edit the overscan.prefs file in the prefs/Env-Archive/sys/
- drawer with your favourite filezapper, and change the value $10 to $15
- at offset $039 (this only if the Euro36 is the first in the list in
- the overscan prefs, otherwise the offset will be a different one).
-
- Now, if everything went right, you should have in your screen mode requester
- the Euro36 mode. Load the Screenmode pref and look at the values of the
- frequencies. They shouldbe 71hz and 15.64khz in a maximum resolution of
- 1280x400. Try to select it and hope...
-
- NOTE: You are risking to melt down your monitor, so if something looks
- wrong, turn the monitor off immediately ! (you are advised)
-
- Advantages of this method:
-
- - A 71hz interlaced screen flickers way less even than an NTSC one
- (try it with Imagine !)
- - Appartently the DMA is not slowed down by it (unlike the DBLPAL 8(,
- and some times it even looks like the refresh is faster)
-
- Disadvantages:
-
- - The screen height is limited to 400 pixels, like in NTSC.
- - Only horizontal overscan is possible.
-
- I have no idea on which monitors this trick will work on, but on my 1084S
- it works great since last year, even if the manual says it is only 50hz.
- This trick *DOES* *NOT* work on TVs (no way, don't even try) but it should
- work on other similar monitors that support NTSC. Let me know about it.
-
- ***********************************************************************
- This document was originally posted on the italian Amiga Fidonet areas.
- It is on Internet by written permission of the author. This is one of
- the many contributions the Italian community gives to the Amiga users.
- ***********************************************************************
-
- All the info you need is here. Please don't send messages unless really
- necessary. Thanx are appreciated though 8') However, if you are successful
- in using this trick, please send us a message specifying your monitor
- bran, model, and year of production, so we can include it in future
- releases of this document.
-
- Fidonet : 2:334/21.45 Francesco Ronchi ( author )
- 2:332/516.7 Federico Chiesa (translator)
-
- Internet : so98@delta0.lica.unimo.it (translator) until summer 95
-