GLaBIOS and Hercules graphics.

[n9tax]

Just curious about the support for Hercules graphics. I have a bone stock IBM 5150. Using the appropriate release pre-compiled binary of GLaBIOS the machine works as expected with a CGA card. However I get no video with a Hecules card. I am able get video with the stock BIOS so the card is functional. Do I need to compile in an option for that card to work? Thank you for any guidance you can provide. And thank you for an amazing project!

[640-KB]

Hello! All of the standard builds support CGA and MDA/Hercules. Have you checked the DIP switches on the motherboard for the video adapter type? Basically made sure SW1 switches 5 and 6 are set to OFF.

Here's a really great little tool from Adrian Black to set them up.

Let me know if that does the trick!

640KB

[n9tax]

I figured this would be the case. Just thought I would confirm before going down a rabbit hole of troubleshooting and have it be some setting I glazed over. As stated above. The system works with the original bios. So yes the jumpers were set to MDA. As soon as I swap in the GLaBIOS the machine boots as I can hear the beeps. Just no video. I will investigate further. Thank you for the quick reply.

[640-KB]

Oh wait - you did say 5150. Do you have the 5150 version, 8P? Yeah, the DIP switch hardware is different on the PC so the non-5150 versions read them incorrectly and cause exactly what you are seeing!

Try this one:

https://github.com/640-KB/GLaBIOS/releases/download/v0.4.2/GLABIOS_0.4.2_8P.ROM

[n9tax]

Yes the tests were performed with the GLABIOS_0.4.2_8P.ROM

[640-KB]

Here's another question: do you eventually get video, like right about when DOS boots? I have seen with one particular HGC clone card that happens and I have no idea why. If that's the same for you, I can try to dig into it further (just assumed it was a buggy clone chip).

[n9tax]

I don't think this is a clone. Pretty sure it's a legit Hercules card. And Truth be told I had no drives connected to the system at the time.

[640-KB]

Just to rule it out, could you try a different version, say this one?

https://github.com/640-KB/GLaBIOS/releases/download/v0.4.0/GLABIOS_0.4.0_8P.ROM

I have that exact card (in fact it's in the machine I use most often for testing), but who knows. I can try it in my 5150 later and see what happens there.

[n9tax]

I sure can. Later today as I am not in a place to set that up right this moment.

[n9tax]

So this is an odd thing. With all of the cards plugged in and the drives connected the video works fine with the Hercules card. Both the newer and older Bios you provided. The original testing was just a memory card and the Video card.

[640-KB]

Interesting! I don't really have a good guess what that would be, but I'm glad it's working!

Curious - are you using a OneROM for the 5150?

[640-KB]

Oh, and yes that's the same Hercules Plus that I have!

[n9tax]

Interesting! I don't really have a good guess what that would be, but I'm glad it's working!

Curious - are you using a OneROM for the 5150?

Yes I am using a OneROM. Pretty awesome device. Certainly makes fiddling with different BIOS a complete breeze. And yes I am not sure what the issue with the card was originally. That machine was a later 5150. I just got a 16-64K machine up and running. I am going to see if I can repeat the issue on that one. I have the other all back together now and don't want to rip it all apart again. Maybe it was just a fluke or I did indeed have a dip switch set incorrectly.

[640-KB]

Yeah, really cool device - especially on a 5150 where finding an easily writeable DIP 24 EPROM isn't as easy. I don't yet have one myself, but I plan to get one or two of different sizes.

Let me know how everything goes with testing the others!

640KB