Does your CONFIG.SYS load HIMEM at all?

Try loading that by itself without the EMM and see if the game runs.

Setting up that startup text screen is the first thing the Keen 4-6 games do when you start them. This is done by copying a block of data into video memory. That block of data has all the memory numbers replaced with xxxxx initially, then the game proceeds to start up its memory manager, input and sound routines. After that, the memory part is updated with the correct values for your system (and the detected graphics card, sound card and input devices are also highlighted).

If your system hangs while the memory is still showing xxxxx (and the text at the bottom says "Initializing"), then something went wrong while setting up the memory manager or the sound- or input manager. If disabling EMMBOX3.SYS fixed that, then it probably was an EMS memory issue. The memory manager was probably trying to quit with an error message, but there's a bug in the Keen games that causes them to make the system hang whenever they try to quit with an error message before they entered graphics mode (the bug causes them to set the first 64k of your system's memory to 0, erasing the entire interrupt vecor table and the BIOS data area).

Keen 4-6 can only make use of up to 1 Meg of memory, so they can only use up to 64k of EMS (if present) and up to 200k of XMS (if present and not used by DOS). If you have your CONFIG.SYS set up to allow DOS to use UMBs (DOS=HIGH,UMB or DOS=UMB), then the Keen games won't be able to use XMS at all. Also, you absolutely need to have UMB support for the Keen games to use XMS, which means you need to load EMM386 or a similar tool that provides UMBs. I recommend using the DOS=HIGH,NOUMB setting for Keen 4-6 if you want to squeeze the maximum amount of memory out of your system. By the way, if you ever do manage to make the game use XMS (Extended) memory, the startup screen may show less XMS memory than what's actually used by the game. You may have 64k or 128k more than whatever the game tells you.

All that being said, 339k of "Total" memory on the startup screen should be enough for playing the original Keen 4.

So whilst I was indeed able to run the game once I'd removed the EMMBOX3.SYS driver, now I've installed the Opti sound card drivers I'm down to 226k, with which the game no longer loads.

I've tried using DOS 6.22's built in memmaker, but that's still not freed up enough conventional memory to run the game.

Opti sound card drivers?

What sound card is this?

A 386 should have an SB 2.0 or SB Pro, or whatever cheap SB Pro clone you can get to put in there. No drivers required.

keenmaster486 wrote on 2021-07-12, 15:00:

Opti sound card drivers?

What sound card is this?

A 386 should have an SB 2.0 or SB Pro, or whatever cheap SB Pro clone you can get to put in there. No drivers required.

It's an Opti 82C933 chipset card that is SBPro compatible. Before I installed the driver diskette Keen would only show PC Speaker available. Now it's installed I get a checkmark against Sound Blaster/AdLib.

I've actually managed to get the game to report 335Kbytes free now so it runs again, but the latest issue is checkerboarding across the bottom half of the screen. Scrolling is still smooth however and the game runs as normal besides the glitching.

Other games (such as WCLB) don't glitch out so I don't believe it's the video card at fault.

Okay -- use this project here: UNISOUND - Universal ISA PnP Sound Card Driver for DOS v0.81b to initialize the card without leaving drivers loaded in memory. That will free up some for you. As for the video card, probably worth it to remove it, clean the terminals, and reseat.

Thanks, that's solved the sound card and memory issue.

I've cleaned the ISA slots twice now, and the video card. The issue remains.

Here's a video of the PC happily playing Bumpy's Arcade Fantasy:

https://www.oldpc.co.uk/vogons/bumpy.mp4

And here's a video showing the corruption on Keen4:

https://www.oldpc.co.uk/vogons/keen4.mp4

If it were a hardware failure on the part of the video card (memory usually causes checkerboarding from what I remember), then I'd not expect the checkerboard area to change in screen area as I scroll vertically.

What's the model of the video card?

It’s a 2TheMax 2MB Tseng ET4000AX based card.

I’ve owned it from new, it only got its first installation 3 years ago!

Ahhhhhh.

So the Tseng cards do not like Commander Keen. It's unfortunate, but true.

Check this chart for compatibility across several games checked vs several cards: https://gona.mactar.hu/DOS_TESTS/

Ah, that would explain it. I was aware of (was it Matrox?) issues with scrolling, but not Tseng cards having graphical problems 🙁

Guess I need to source a different ISA VGA card then. Any suggestions?

Western Digital is a good place to start. S3 and Cirrus Logic are probably good too.

keenmaster486 wrote on 2021-07-13, 15:38:

Ahhhhhh.

So the Tseng cards do not like Commander Keen. It's unfortunate, but true.

Check this chart for compatibility across several games checked vs several cards: https://gona.mactar.hu/DOS_TESTS/

My ET4000 works perfect in keen4/5/6 with "SVGA compatibility" turned on

maxtherabbit wrote on 2021-07-13, 16:01:

keenmaster486 wrote on 2021-07-13, 15:38:

Ahhhhhh.

So the Tseng cards do not like Commander Keen. It's unfortunate, but true.

Check this chart for compatibility across several games checked vs several cards: https://gona.mactar.hu/DOS_TESTS/

My ET4000 works perfect in keen4/5/6 with "SVGA compatibility" turned on

Could you elaborate please? I don’t recall an SVGA compatibility setting for Keen itself, is it a command line switch, or are we talking something loaded during boot?

SVGA compatibility setting (along with "fix jerky motion") is in the config settings somewhere. There's an (undocumented?) command line switch for it too.

However, with my ET4000 I was never able to get that setting to fix anything.

I’m not with the machine right now, but will try later, it can’t hurt before ordering another card!

SVGA Compatibility did indeed fix the corruption, all the Keen games play just fine now!

Great, glad that worked! Wish it worked for me... I've never experienced it working.