Just wanted to do a quick update on some of this:

New things I tried:
* New harddrive
* New PSU
* New sound card (specifically chose a VIA Envy24 based chip with no hardware acceleration)
* Removed Win2K and installed WinXP SP3 so I can try newer Deus Ex mods
* Re-installed Deus Ex from the GOTY CD I have rather than extracting my GoG version I was previously using
* Used AmigaMerlin's XP drivers for the V5

--- observations ---
None of this helped. Oddly though after re-installing Deus EX from the GOTY CD it went into the save menu and saved (on level1 on the docks) in 640x480, soon as I upped the res to 1024x768 and tried saving it froze on the save screen again!!!
I then installed the Deus EX community mod pack with Trancendance and gave it a try. Of course, I made sure to go into the mod's system folder and delete all the nGlide files, so that it used my systems hardware Glide. Configured to use Glide and Galaxy3D audio. Loaded the game... guess what, it's saving. I start up level 1, on the docks.. save. Change res, try again, saves ok!!!

I am so confused. I'm not counting my chickens yet. I mean, all along this could have been a corrupted installation. But I had previously re-installed from the Gog pack and it didn't help. Also the CD version still crashed on save too. All other games are fine, even Unreal Engine 1 games just like Deus Ex, so it has to be a game specific problem. But it doesn't make sense how I literally played up to the Hong Kong level without any saving issues and then all of a sudden this started happening. None of this makes sense!

I'll start a play-through on this new community modded version with trancendance and see how I go, fingers crossed.

Quick update, it crashed on save again. I'm starting to think it is related to frame rate. If I try to save while looking at liberty island it'll crash, if I save while looking out to sea it doesn't.

I am now convinced this is a motherboard issue... even though I've re-capped it. I did some googling and found mention of the 'TUSL2-C siren crash' which describes this issue well. I have also found that this has started to happen in other games too, not just Deus Ex. I've ordered a cheap replacement motherboard to test.

Google cached copy of the siren crash thread:
https://webcache.googleusercontent.com/search … ent=firefox-b-d

mzry wrote on 2022-05-25, 13:16:

I swap from using my IDE CF Card game drive, copied the game to C:\ which is Adaptec SCSI, still the game locks on save, so it isn't a dodgy CF card...

I had a similar "crash on save" problem on Warcraft II using a CF card as the main drive. Solved by keeping the mouse stationary during saving. Don't know if this info helps but that's my two cents.

Just to update this thread: As mentioned in that archived forum I linked to, I managed to find myself another TUSL-2 board, but this time one made in Taiwan! Now I can save in Deus Ex again 😉 Very happy! Who knows what component fails over time on the Chinese made boards, but it's certainly a real issue. I noticed that the Intel chipset on the Taiwan board was made in Malay, where as the Chinese one was made in Korea, just an observation. But from an electronics stand-point, it could be the voltage regulators they use on the board - perhaps the brand quality used isn't as good, there are many of them. Since the issue was reproducable, I can only speculate that going to 'save' in the game triggers the SCSI card (I am using SCSI) to access the disk, perhaps that causes a voltage drain on the PCI bus due to bad regulation and therefore causes a crash - I don't know though, just guessing.

In Far Future i Play Deus Ex

I Remember, Deus EX was 2000 my First PC Shooter.