I can't see why not. Ultimately the cards might not be 100% register compatible with CGA or EGA but otherwise i have enough cards to try it...if i had a RGB TTL monitor...

interesting... there is no need for 100% cga/ega compatibility, if I can get vga games to display on the 1084 I'll be more than happy 😀
Alas, I have no such cards anymore... I need to search for one it seems 😉

edit:

It might not work though - 1084 accepts a 15khz TTL signal (CGA for example is great with it) but vga will be 31khz... do the dual-port vga cards take care of this?
There are some schematics here: http://www.epanorama.net/circuits/vga2rgbs.html but I doubt any will work with a 15khz-only monitor...
I think this is a lost cause, the 1084 will apparently support up to CGA reoslutions (for example EGA 640x200 works but nothing above that). It's too bad it is not easy to make a vga->RGB/15khz adapter ... there goes another idea to save space on the desk 😵 🤣

The 9-pin output on those old VGA cards only works with CGA and EGA TTL video modes. VGA is only supported on the HDI-15 output. The adapter above just combines the separate vertical and horizontal sync lines into composite sync, its still 31.5khz VGA video.

^ yeah, did some more research - it seems there is no point trying...

keropi wrote:

interesting... there is no need for 100% cga/ega compatibility, if I can get vga games to display on the 1084 I'll be more than happy 😀
Alas, I have no such cards anymore... I need to search for one it seems 😉

Huh, i never understood you wanted VGA out of the DB-9 connector.

Yep there's no point in trying, it is exclusively for CGA, EGA and Hercules/MDA.

Just in case anyone has the same question in the future I will write my experience with the Diamond Flower VG-7000 card

- it is based on the OTI067 chipset and it is faster than my Paradise PEGA2A card
- you can jumper it down to CGA/EGA modes and it does indeed work fine with real CGA/EGA monitors - "serious" stuff is OK
- in EGA mode some games still detect it as a VGA card (mainly those that use auto-detection) and this results in either wrong colors or a garbled/out-of-sync image when using a real EGA monitor . It's a per-case problem so there is no utility that fixes that... (I also tried my EIZO multisync monitor, when a game has issues it's not correct even there, the image might sync but you can only see half of it for example... 🤣 )
- OAK's VGAMODE.EXE can be used to lock again the card in EGA mode and it helps sometimes to fix the wrong colors some games display
- When the card is jumpered in CGA/EGA mode most recent versions of VGAMODE.EXE do nothing (they work fine when the card is in VGA mode). I have found that versions 1.07 and 1.09 do work when the card is jumpered to CGA/EGA mode.

If the card could really be jumpered down to EGA mode it would be a nice alternative to a real EGA card , I haven't found anything weird happening other than games insisting on using it as a VGA card.
Needless to say that as it was pointed by previous posters VGA modes are not displaying through the 9pin TTL port - and if they do the colors are all wrong.
I haven't tested many CGA stuff but games I tested that fail in EGA mode work when the card is in a CGA state (Rick Dangerous 2 for example, it needs VGAMODE.EXE to double-select EGA mode in order to get correct colors - works fine in CGA mode without extra steps)

VGA through 9pin TTL means limitation to 64colors right?
Does this mean EGA color-output, or is 16colors with VGA palette is possible?

dr.zeissler wrote on 2024-09-23, 10:24:

VGA through 9pin TTL means limitation to 64colors right?
Does this mean EGA color-output, or is 16colors with VGA palette is possible?

TTL is 16 or 64 colors (or mono). Analog RGB is needed to get full VGA color.

Analog RGB in a 9-pin connector is not unheard of, though I don't know of anything that used it besides some Amiga add-on boards.

Early VGA cards offer 9 and 15 pin Output.

bakemono wrote on 2024-09-23, 16:59:

dr.zeissler wrote on 2024-09-23, 10:24:

VGA through 9pin TTL means limitation to 64colors right?
Does this mean EGA color-output, or is 16colors with VGA palette is possible?

TTL is 16 or 64 colors (or mono). Analog RGB is needed to get full VGA color.

Analog RGB in a 9-pin connector is not unheard of, though I don't know of anything that used it besides some Amiga add-on boards.

Analog 9-pin RGB is a thing. The IBM PGA ("professional graphics adapter") used analog RGB on a DE9 connector. The pinout of that connector seems to have gotten the most common pinout of analog 9-pin RGB. This pinout is present on a couple of analog/digital monitors like the NEC MultiSync II (and likely the original NEC MultiSync as well).

On the other hand, while I've seen a lot of EGA and VGA graphics cards, I have yet to see a EGA/VGA card that uses its 9-pin connector for analog output, especially if it also has a 15-pin connector.

On EGA/VGA combination cards, it is extremely likely that the digital RGBI/RGBrgb output (16/64 colors) is tapped from the circuit before the RAMDAC (that provides 256 out of 262144 colors), but after the EGA attribute controller (that provides 16 out of 64 colors). So you can get the 64 EGA colors on the digital output, but any changes to VGA palette registers will be ignored on the digital output.

Annoyingly the IBM "analog RGB on DE-9" pinout is quite different from the commodore monitors which also can accept analog RGB (or TTL) on their DE-9 inputs. The commodore monitors use the same pins as the CGA TTL RGBI pinout but they require composite sync instead of H/V

maxtherabbit wrote on 2024-09-23, 22:34:

Annoyingly the IBM "analog RGB on DE-9" pinout is quite different from the commodore monitors which also can accept analog RGB (or TTL) on their DE-9 inputs. The commodore monitors use the same pins as the CGA TTL RGBI pinout but they require composite sync instead of H/V

Interestingly, the PGA (the original IBM 9-pin analog RGB) also used composite sync (on pin 4) and used pin 5 for switching between CGA (15.7kHz) and PGA (30.5kHz) mode. 3rd-party monitors often ignore pin 5 as mode signal and auto-switch depending on frequency. Instead, they optionally accept VSYNC on pin 5, allowing HSYNC instead of CSYNC being fed into pin 4.

keropi wrote on 2017-07-03, 11:43:

- it is based on the OTI067 chipset and it is faster than my Paradise PEGA2A card - you can jumper it down to CGA/EGA modes and […]
Show full quote

- it is based on the OTI067 chipset and it is faster than my Paradise PEGA2A card
- you can jumper it down to CGA/EGA modes and it does indeed work fine with real CGA/EGA monitors - "serious" stuff is OK
- in EGA mode some games still detect it as a VGA card (mainly those that use auto-detection) and this results in either wrong colors or a garbled/out-of-sync image when using a real EGA monitor . It's a per-case problem so there is no utility that fixes that... (I also tried my EIZO multisync monitor, when a game has issues it's not correct even there, the image might sync but you can only see half of it for example... 🤣 )
- OAK's VGAMODE.EXE can be used to lock again the card in EGA mode and it helps sometimes to fix the wrong colors some games display
- When the card is jumpered in CGA/EGA mode most recent versions of VGAMODE.EXE do nothing (they work fine when the card is in VGA mode). I have found that versions 1.07 and 1.09 do work when the card is jumpered to CGA/EGA mode.

@keropi
beside the general discussion here...could you please test if the effects on "beverly-hills-cop" do work on that OTI card if it is switched to EGA/TTL mode?
I do not have such a card and my ET4000 and the others I tested failed on that "hardcoded" effects. My Schneider TowerAT with ParadiseEGA/CGA/MDA chip does display the effects correctly.... I don't know if the effects require to be displayed in TTL rather than analoge.

My ET4000 is mostly overkill for the 256colors in my A2286/8 Bridgeboard...using 16colors in VGA pal is the key to good framerates.
There are some early VGA titles that support that (Gods, Xenon2, etc.) and some early demoscene stuff too.... but there are some EGA
games that seem to be "hardcoded" to EGA registers that do not work properly on these VGA cards...."beverly-hills-cop" is one of them.

dr.zeissler wrote on 2024-09-24, 06:43:

beside the general discussion here...could you please test if the effects on "beverly-hills-cop" do work on that OTI card if it is switched to EGA/TTL mode?[...]

IIRC I no longer have this card 🙁