MiSTer FPGA Forum

Are there any recommended mister ini settings for the ao486 core when connecting via a HDMI to VGA adapter to a PC CRT?

On the menu I have a rock solid signal with these settings:

[Menu]
forced_scandoubler=1
video_mode=0
fb_terminal=1

But cannot get the CRT to sync on the ao486 core (the video mode is reported as : 26.82 Khz)

[ao486]
vsync_adjust=0
video_mode=6

According to the comments in MiSTer.ini, video_mode=6 is 640x480@60. Did you try any higher resolutions?

For this core I have the best success in using the scaler for the VGA output, is this enabled in the ini?

CapnChaosDK wrote: ↑Sat Jun 06, 2020 5:36 pm For this core I have the best success in using the scaler for the VGA output, is this enabled in the ini?

Thanks for the suggestion.

I believe the vga_scaler setting is only applied to the IO board VGA out rather than the HDMI port with:

direct_video=1

enabled.

I can get my MiSTer to output a valid 31.6KHz signal with vga_scaler and forced_scandoubler both on and the resolution hard-coded to mode 6 (640x480@60Hz). I'm using an IBM 8513 12" PS/2 color monitor to display my signal.

If I turn vga_scaler off, it will output clean signals on most cores, but the Altair8800, AO486, EDSAC, and MacPlus cores all have problems on the output related to h-sync.

Altair8800 displays a duplicated image, but it's clean enough that I can see the menu and get out. On my multisync monitor, it comes up as a 45.07KHz h-sync signal.

AO486 has some fairly serious h-sync issues on my PS/2 monitor. It displays OK on my multi-sync monitor, but the text wiggles a little and the OSD has a serious problem with dot crawl (it outputs a 26.82KHz h-sync signal).

EDSAC also outputs a strange h-sync signal that neither my PS/2 nor my multi-sync monitor like, 45.75KHz.

MacPlus also has a serious h-sync issue, not even displaying on my multi-sync monitor. On my PS/2 monitor, it has a similar look to the AO486 core. I was able to grab the h-sync rate by displaying it on my HDMI screen -- 22.26KHz.

The simple answer with *all* of these cores is to turn vga_scaler on, and then the MiSTer outputs a fixed H-31.6KHz / V-60Hz signal regardless of core.

I also can't get the ao486 core to output to a PC CRT without using the scaler. It's sad because with the scaler text in DOS looks like crap. The strange thing is it did work once when I was setting it up and outputting to HDMI and the PC CRT at the same time

ok so I figured out how I had it working before, I set video mode 6, composite sync off, vga_scaler off, and in the menu for the ao486 core set Vsync to variable. Now the DOS text looks like I remember, although there is a little flicker. That might just be my older eyes though it seems to steady out once it warms up.

I don't understand why you need to set a video mode, should the core not decide this?

tried to connect a VGA monitor directly to IO board VGA output?

Well connecting this directly to my XM-29 VGA Monitor worked, but the sync issue seems to be when running in Composite Sync Mode. I have a BVM-32*** and I don't think it accepts H + V VGA Sync without some external hardware, but the XM29 works fine.

I kinda of wonder, for computer cores, maybe having a combine sync option in the cores would be great so we could play console and computer cores on RGB+CSync setups. ? Don't know if that would be hard to add, but sure would make it easier to run both kinds of cores on CSync monitors.

If anyone else knows away to get the core to work correctly with a CSync setup, I'm all ears.

-The Bastard

Looking at the manual for the BVM-32 series, there appears to be lots of potential configuration gotchas, as each input is configurable through on-screen menus -- as well as the requirement to use a 75-ohm terminator on the SYNC OUT line when using RGB-mode + C-SYNC.

Wow, this actually worked for me, thanks. I now have that old, natural scanline look in DOS. Unfortunately, starting any DOS games results in out of sync on my monitor. I guess it's because the DOS games try to use 320x200, which is not in my MiSTer.ini. I don't know if it's possible to have multiple video_mode lines in there. Have you had any success with any DOS games?

bengmo wrote: ↑Tue Jul 07, 2020 9:58 pm ok so I figured out how I had it working before, I set video mode 6, composite sync off, vga_scaler off, and in the menu for the ao486 core set Vsync to variable. Now the DOS text looks like I remember, although there is a little flicker. That might just be my older eyes though it seems to steady out once it warms up.

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=0       ; 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)
volumectl=0            ; enable audio volume control by multimedia keys
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=0         ; 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

; 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=0

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

; 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

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

; 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
;
; 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=6

; set to 1-10 (seconds) to display video info on startup/change
video_info=5

; 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=1

; 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=57
;refresh_max=63

; 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

Without scan-doubler, does it not require a 15khz monitor? I am planning to Try out different monitors with the MiSTer. I am not sure how to connection the MiSTer with VGA to a Commodore 1084S with... I think its connector is called RGB.