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Cannot change resolution for ao486 on 15khz 1084s monitor

Posted: Thu Aug 24, 2023 9:49 pm
by neuron81

Hi!

I am trying to display ao486 on a 15khz 1084s monitor.

It kind of works but the image is slightly stretched vertically. This results in some doubled lines which is nasty. The image also slightly cropped vertically.

core is at: 320x200 70hz
output is at: 640x240 60hz

But the output should be 320x200, see my config below. This could explain the stretching. Why is my video_mode below not taken? Am I writing the config wrong?

I used chatgpt to generate the line, but other lines taken from the various forum posts on this topic also did not work:
https://chat.openai.com/share/3565cbef- ... dcaaf5462d

Any help appreciated!

Thank you.

Code: Select all

[MiSTer]
key_menu_as_rgui=0 ; set to 1 to make the MENU key map to RGUI in Minimig (e.g. for Right Amiga)
forced_scandoubler=0 ; set to 1 to run scandoubler on VGA output always (depends on core).
ypbpr=0 ; set to 1 for YPbPr on VGA output.
composite_sync=1 ; set to 1 for composite sync on HSync signal of VGA output.
vga_scaler=0 ; set to 1 to connect VGA to scaler output.
hdmi_audio_96k=0 ; set to 1 for 96khz/16bit HDMI audio (48khz/16bit otherwise)
keyrah_mode=0x18d80002 ; VIDPID of keyrah for special code translation (0x23418037 for Arduino Micro)
vscale_mode=0 ; 0 - scale to fit the screen height.
; 1 - use integer scale only.
; 2 - use 0.5 steps of scale.
; 3 - use 0.25 steps of scale.
vscale_border=0 ; set vertical border for TVs cutting the upper/bottom parts of screen (1-399)
;bootscreen=0 ; uncomment to disable boot screen of some cores like Minimig.
mouse_throttle=10 ; 1-100 mouse speed divider. Useful for very sensitive mice
rbf_hide_datecode=0 ; 1 - hides datecodes from rbf file names. Press F2 for quick temporary toggle
menu_pal=0 ; 1 - PAL mode for menu core
hdmi_limited=0 ; 1 - use limited (16..235) color range over HDMI
; 2 - use limited (16..255) color range over HDMI, for VGA converters.
direct_video=1 ; 1 - enable core video timing over HDMI, use only with VGA converters.
fb_size=0 ; 0 - automatic, 1 - full size, 2 - 1/2 of resolution, 4 - 1/4 of resolution.
fb_terminal=1 ; 1 - enabled (default), 0 - disabled
osd_timeout=30 ; 5-3600 timeout (in seconds) for OSD to disappear in Menu core. 30 seconds if not set.
; Background picture will get darker after double timeout
osd_rotate=0 ; Display OSD menu rotated, 0 - no rotation, 1 - rotate right (+90°), 2 - rotate left (-90°)

; 1 - enables the recent file loaded/mounted.
; WARNING: This option will enable write to SD card on every load/mount which may wear the SD card after many writes to the same place
; There is also higher chance to corrupt the File System if MiSTer will be reset or powered off while writing.
recents=1

; lastcore - Autoboot the last loaded core (corename autosaved in CONFIG/lastcore.dat) first found on the SD/USB
; lastexactcore - Autoboot the last loaded exact core (corename_yyyymmdd.rbf autosaved in CONFIG/lastcore.dat) first found on the SD/USB
; corename - Autoboot first corename_*.rbf found on the SD/USB
; corename_yyyymmdd.rbf - Autoboot first corename_yyyymmdd.rbf found on the SD/USB
bootcore=lastcore ; uncomment to autoboot a core, as the last loaded core.

; 10-30 timeout before autoboot, comment for autoboot without timeout.
bootcore_timeout=4

; Option to load the custom font. Format is plain bitmap 8x8.
; Supported sizes of font:
; 768 bytes - chars 32-127 (only alpha + numeric)
; 1024 bytes - chars 0-127
; 1136 bytes - chars 0-141
; up to 2048 - only chars 0-141 will be used.
; if first 32 chars are empty (for sizes 1024 bytes and more) then they are skipped.
font=font/myfont.pf

; USER button emulation by keybaord. Usually it's reset button.
; 0 - lctrl+lalt+ralt (lctrl+lgui+rgui on keyrah)
; 1 - lctrl+lgui+rgui
; 2 - lctrl+lalt+del
; 3 - same as 0 (lctrl+lalt+ralt on keyrah)
reset_combo=0

; set to 1 for DVI mode. Audio won't be transmitted through HDMI in DVI mode.
dvi_mode=0

; 0 - 1280x720@60
; 1 - 1024x768@60
; 2 - 720x480@60
; 3 - 720x576@50
; 4 - 1280x1024@60
; 5 - 800x600@60
; 6 - 640x480@60
; 7 - 1280x720@50
; 8 - 1920x1080@60
; 9 - 1920x1080@50
;10 - 1366x768@60
;11 - 1024x600@60
;12 - 1920x1440@60
;13 - 2048x1536@60
;
; custom mode: hact,hfp,hs,hbp,vact,vfp,vs,vbp,Fpix_in_KHz
; video_mode=1280,110,40,220,720,5,5,20,74250
video_mode=0

; set to 1-10 (seconds) to display video info on startup/change
video_info=3

; Set to 1 for automatic HDMI VSync rate adjust to match original VSync.
; Set to 2 for low latency mode (single buffer).
; This option makes video butter smooth like on original emulated system.
; Adjusting is done by changing pixel clock. Not every display supports variable pixel clock.
; For proper adjusting and to reduce possible out of range pixel clock, use 60Hz HDMI video
; modes as a base even for 50Hz systems.
vsync_adjust=0

; If you monitor doesn't support either very low (NTSC monitors may not support PAL) or
; very high (PAL monitors may not support NTSC) then you can set refresh_min and/or refresh_max
; parameters, so vsync_adjust won't be applied for refreshes outside specified.
; These parameters are valid only when vsync_adjust is non-zero.
refresh_min=0
refresh_max=0

; These parameters have the same format as video_mode.
; You need to supply both PAL and NTSC modes if you want vsync_adjust to switch between
; predefined modes as a base. This will reduce the range of pixel clock.
;video_mode_ntsc=0
;video_mode_pal=7

; 1-10 (seconds) to display controller's button map upon first time key press
; 0 - disable
controller_info=6

; JammaSD/J-PAC/I-PAC keys to joysticks translation
; You have to provide correct VID and PID of your input device
; Examples: Legacy J-PAC with Mini-USB or USB capable I-PAC with PS/2 connectors VID=0xD209/PID=0x0301
; USB Capable J-PAC with only PS/2 connectors VID=0x04B4/PID=0x0101
; JammaSD: VID=0x04D8/PID=0xF3AD
jamma_vid=0x04D8
jamma_pid=0xF3AD

; Disable merging input devices. Use if only player 1 works.
; Leave no_merge_pid empty to apply this to all devices with the same VID.
;no_merge_vid=0x045E
;no_merge_pid=0x028E

; Same as above but can add multiple devices (one entry per VIDPID). Format is VIDPID in hex number
;no_merge_vidpid=0x12345678
;no_merge_vidpid=0x11112222

; Speeds in sniper/non-sniper modes of mouse emulation by joystick
; 0 - (default) - faster move in non-sniper mode, slower move in sniper mode.
; 1 - movement speeds are swapped.
sniper_mode=0

; Uncomment following option if you don't want to see a second line for long file names in listing.
;browse_expand=0

; 0 - disable MiSTer logo in Menu core
logo=1

; Custom shared folder for core supporting this feature (currently minimig and ao486 only)
; Can be relative to core's home dir or absolute path.
; Path must exist before core start to use it, or it will fail.
; Make sure USB device is mounted before use shared folder on USB!
shared_folder=

; Custom aspect ratio
;custom_aspect_ratio_1=16:10
;custom_aspect_ratio_2=1:1

; use specific (VID/PID) mouse X movement as a spinner and paddle. Use VID=0xFFFF/PID=0xFFFF to use all mice as spinners.
;spinner_vid=0x1BCF
;spinner_pid=0x0005

; spinner_throttle with base value 100 gives one spinner step per one tick. Higher value makes spinner slower.
; Lower than 100 makes spinner faster. Negative value gives opposite direction.
;spinner_throttle=-50

; 0 - X axis, 1 - Y axis.
;spinner_axis=1

; Default filters for video scaler and audio. Paths must be relative to scaler/audio filter folder without leading slash.
;vfilter_default=LCD Effects/LCD_Effect_07.txt
;afilter_default=LPF2000_3tap.txt

; Defines internal joypad mapping from virtual SNES mapping in main to core mapping
; Set to 0 for name mapping (jn) (e.g. A button in SNES core = A button on controller regardless of position on pad)
; Set to 1 for positional mapping (jp) (e.g. A button in SNES core = East button on controller regardless of button name)
gamepad_defaults=0

; Write out file name under the cursor in browser for external integration
; External application or script may parse the info and do some additional actions and/or send info to 3rd party server.
; Warning: it may slowdown the system or add lag while browsing the files in OSD depending on external app/script.
log_file_entry=0

; Automatically disconnect (and shutdown) Bluetooth input device if not use specified amount of time.
; Some controllers have no automatic shutdown built in and will keep connection till battery dry out.
; 0 - don't disconnect automatically, otherwise it's amount of minutes.
bt_auto_disconnect=0

[ao486]
direct_video=1
vscale_mode=0
vscale_border=1
video_mode=320,8,48,24,200,2,2,20,6000
;video_mode=640,8,58,78,240,1,3,18,12324
;video_mode=1280,132,140,281,240,15,0,19,30133
;video_mode=720,24,64,88,240,3,10,6,13500
;video_mode=640,55,90,131,200,34,0,40,15058
;video_mode=640,65,60,108,224,16,0,26,13919
;video_mode=640,54,56,106,224,16,0,28,13764
;video_mode=640,6,56,66,224,14,8,18,12000
;video_mode=640,16,64,80,240,1,3,14,12380

Re: Cannot change resolution for ao486 on 15khz 1084s monitor

Posted: Fri Aug 25, 2023 5:05 am
by FoxbatStargazer

direct_video=1 so your video_mode is being completely ignored. Ao486 has some kind of default resolution/scaling it will do with direct_video, its not designed to be pretty but will at least get a stable image on 15khz. Set direct_video=0 in [ao486] if you want your mode to do anything at all.


Re: Cannot change resolution for ao486 on 15khz 1084s monitor

Posted: Mon Aug 28, 2023 7:29 pm
by neuron81

Thank you so much! There is a lot of confusion in the forums on this topic but your take is spot on.

Just found an older config that you posted and it perfectly fixes the vertical crop and double line issues when running 320x200 DOS titles.

viewtopic.php?p=26362#p26362

[ao486]
direct_video=0
video_mode=720,24,64,88,240,3,10,6,13500
vscale_mode=0
vscale_border=20

Thank you!