Commodore PC10-III: CGA on a mono monitor?

[AlexC]

This PC has a Paradise PVC4 graphics chip, which I think is like an ATI Small Wonder. As far as I'm aware that means it can do emulated MDA/Hercules graphics on a CGA monitor. But the reverse appears not to be true: it can't do hardware-emulated CGA on a mono monitor.

I have tried, using gs.com and vset.exe, but when I put the chip into 'emulated' mode (or 132-column text mode) the screen goes blank and/or whines as though the frequency is out of range (which it probably is). Fiddling with the four DIP switches at the back has a similar effect. This is true with both the mono monitors I own.

So, to save me further effort, am I stuck with using software CGA emulation on this system? That's no big deal really, but I'd like to be sure that I'm not missing something.

 

[Timo W.]

What type of "mono" monitor are you using? Most will do MDA/Hercules only, but there are also some that will do CGA or even EGA. So it really depends on the monitor. It must support 15 KHz for CGA to work.

 

[AlexC]

They're both MDA/Hercules. But I can run CGA games on here using software CGA emulation, and I wanted to check that this chip can't do that itself, but slightly better. I'm pretty sure it can do MDA/Hercules on a CGA monitor, without changing the output frequency. I hoped it could also do the reverse, but I suspect not.

 

[per]

The very first ATI Graphics Wonder was sold as a Commodore OEM, but there has never been any picture of one posted on the internet. I am very curious to see how your card looks like if it indeed is a Graphics Wonder!

The Graphics Wonder came in serveral versions. I have little experience with the older small wonders, but the later Single-Chip versions are fully software configurable and I'm pretty sure it does at least some kind of MDA/Hercules emulation on a CGA monitor.

But again, that's regular MDA/Hercules. I seem to remember the manual saying something about 132 column mode being incompatible with emulated modes, but this can be investigated.

 

[AlexC]

I've dug out the manual and read the appendices carefully. Looks like this chip can't do what the Small Wonder can do after all. You can have CGA/Plantronics with a CGA or multisync monitor, and MDA/Hercules with an MDA/mono monitor, but it can't emulate one to the other. The four switches at the back have a different purpose to those on the Small Wonder. Shame, but at least now I know.

 

[AlexC]

The very first ATI Graphics Wonder was sold as a Commodore OEM, but there has never been any picture of one posted on the internet. I am very curious to see how your card looks like if it indeed is a Graphics Wonder!

The Graphics Wonder came in serveral versions. I have little experience with the older small wonders, but the later Single-Chip versions are fully software configurable and I'm pretty sure it does at least some kind of MDA/Hercules emulation on a CGA monitor.

This one's built into the motherboard of the PC10-III and I believe also other models in the Commodore range. Photos here. Unfortunately I think this model was too early to have the emulation features. It's not a big deal, but I'd have thought that CGA emulated in hardware by the graphics chip would be more effective than by a TSR, so it would be nice to have it.