Conference 7.286::atarist

    Note 1020.6 talks about the software solution of overscan.

    Here is some History:

    Overscan started out in Germany by some hackers who were able to
    display pixel graphic in the normally black border outside of the
    640x400 screen.

    A german Mag (STmagazin, Verlag Markt und Technik) had reviews of their
    work and explained how it was done, including assembly listings.
    Later on they wanted to find out what really happend hardware wise and
    traced the signals. This lead to the little hw hack that could give a
    true resoulution of about 800x580 (don't have the exact numbers). This
    hack is somewehre here in this notesfile (around May/June 89).

    The overscan product is actually the same as the old harware hack. But
    the old hack was not very stable (I built it myself and found it worked
    but sometimes I had to reboot several times to get it up.) There were
    other problems, too. The new overscan uses more sophisticated logic to
    generate the neccessary signals and should thus be much more stable.



    ---markus---

    
    Hi me again,
    
    When Overscan came out I actually BOUGHT the ST magazin from GErmany
    and the corresponding Floppy disk containig the OVERSCAN software and a
    few over goodies. 
    
    If anyone wants to try the OVERSCAN drop me a mail, I will LOAN them
    the stuff. (This overscan is exactly as described in -.1 above and
    needs some hacking to the ST hardware, I havnt got round to it yet,
    funny though I revisited the article only a few days ago, and am toying
    with the idea of trying it out.
    
    The reason Is that in the ST user this month was a utility to give you
    a GIANT screen image that you can scroll the screen in. This is a
    purely software hack, installed in auto boot folder. It gives about 3*
    the normal sceeen size. When you want to see whats to one side or
    below, if you position the mouse pointer at the edge the screen scrolls
    across. There are a few GEM progs that run with this. The only draw
    back is the mouse gearing is also upped by a factor of three and
    becomes very coarse. 
    
    This wetted my appetite for a big monitor again! There were some
    adverts in the mags this month for a new video board, that is elcheapo,
    (compared to the existing big screen monitor boards, (this new one is
    199 pounds) however that is still about 190 pounds more than I can
    afford, so his is why I dug the old OVERSCAN article out again!.
    
    Regards
    
    Pat K

    
    Hi,
    
    Since we had a fair bit of snow this weekend, and I couldnt get on with
    building the great wall of Silchester, I decided to play St's.
    
    I took my Xacto knife to the ST PCB, cut the track at the indicated
    place, drilled a hole in the case and wired up a 2SX20 transistor, two
    diodes, a couple of caps and resistors as an emitter follower, combine
    Vsync and Hsync. This feeds the shifter vis a switch - normal -
    hyperscan.
    
    I put the hyperscan prog in the auto folder. Switched to hyper and
    booted -  LO -  after some horrible looking rubbish, as the ST booted, up
    came a FULL screen desktop. I ran GFA DRAFTplus and EASYDRAW with NO
    probs at all. Both programs "expand" to make full use of the screen.
    
    I tried altering the order of boot progs, I have six to play with,
    GPLUS+, two hard disk bios's, TOS1.4 fix, Cache.prg, Shell fix. I
    thought that if Hyperscan came up first, then the start screens would
    look OK, unfortunately, I got bombs that way. It looks as though GPLUS
    always has to be first, and Hyperscan last.
    
    The only drawback to Hyperscan, is since it is using the boarder of my
    SM124 monitor which hasnt been used up to now, and the monitor is three
    years old, there is a difference in the "colour" between the old area
    and the new! I suppose the phosphor in use has "aged".
    
    I tried the Hyperscan on the color monitor. it appears to work OK on
    it as well. However medium res appears to have vanished. GFA draft only
    half works on it, the menu bar disapears off the right hand side of the
    screen, it appears to long compared with the rest of the display.
    
    In conclusion. I have had no trouble with the Hyperscan in MONO. It
    boots every time, and the two GDOS GEM programs I have used work
    reliably.
    
    P.S  Gemini and NEODESK also work on the mono monitor OK.
    
    GET your knives out !!!, The switched Hyperscan costs a few pence, the
    autoswitching software driven autoscan costs 50 pounds. It will
    invalidate your warranty and also the chances of anyone repairing your
    ST commercially tho!. \
    
    PPS it wont work on an STE or  an ST with ROMS pre 1.4. Altough if you
    have tos 1.4 on disk, the Hyperscan prog can work with that.
    
    regards
    
    Pat K.

>    
>    PPS it wont work on an STE or  an ST with ROMS pre 1.4. Altough if you
>    have tos 1.4 on disk, the Hyperscan prog can work with that.

    Pat,

    Any hint that the STE situation may be a temporary one; or are there
    more fundamental problems?

    Carl
>

    
    Hi Carl,
    
    The word is that the signals I butchered on the ST, are inside a PAL on
    the STE, thus inaccessible to physical abuse. There was some jokey mail
    on the USENET about the German Hackers using RF injection to frig the
    scan rates 8>)
    
    Cheers
    
    Pat K.
     

    I installed the Autoswitch Overscan in my Atari 1040STFM lastweekend,
    and it is running without any problems.
    My monitor is an Atari SM144 mono monitor, and the useable screen is
    approx. 25% larger. This means that my desktop has much more space
    (I have the hardware TOS2.06 upgrade installed also) and my main use
    being with Steinberg Cubase, I have more work area on screen,
    especially usefull with the arrange window.
    I have come across only two or three programs that do not run with
    Overscan (e.g. the PD "Revenge" document displayer). In this case,
    it is only necessary to edit the Overscan .INF file, and insert the
    name of any program with which overscan is to be switched off before
    the program runs. Overscan automatically switches off with, for
    example, "Freeze Dried Terminal", which subsequently runs in "normal"
    resolution mode, so that it is only necessary to enter program names
    into the .INF file which do not allow automatic switching.
    The vast majority of my software runs in Overscans full resolution.
    	I am very pleased with the results, and can also confirm that it
    works with the ICD 16MHz CPU hardware upgrade, which I also have installed.
    
    Best Regards,
    Brian
    

    
    Just a note to add that TurboST Mono (software screen accelerator)
    does not run with Overscan (gives a message saying that the resolution
    is not supported), but the ICD licenced version of QUICKST (supplied
    with the ICD 16MHz upgrade) supports overscan O.K.
    
    Best Regards,
    Brian