How do I upgrade the BIOS to 1.44 on a 755CE with a dead battery?

[jordan1776]

I have a 755CE running Windows 95A. I want to get the mwave DSP and soundblaster emulation working so I can use it for DOS gaming. Unfortunately, the previous owner never upgraded the BIOS so I can't use the 95 PnP features. The NiMH battery doesn't hold a charge and shows 0% not charging in Fuel. My options seam to be
a) buy a new battery (unlikely to find one for sale that isn't a scam or already dead)
b) rebuild the battery with new cells (don't have the soldering skills for that and it's a smart battery so I don't think it's as simple as soldering a bunch of cells together)
c) somehow hack the BIOS upgrade to ignore the battery level (I looked all around the forum and I hadn't found a way for this specific model. I saw on a different model there is a flag to force it and on another you can hex edit the flashing file, but nothing for 755C* models)

These are the files on the sytpe144 Upgrade diskette:
11/07/1996 02:33 PM 524,288 $0017000.FL1
11/14/1996 01:44 AM 7,408 COMMAND.COM
11/14/1996 01:44 AM 25 CONFIG.SYS
02/28/1992 12:00 PM 33,446 IBMBIO.COM
02/28/1992 12:00 PM 37,378 IBMDOS.COM
11/14/1996 01:44 AM 43,903 UPDTFLSH.EXE
11/14/1996 01:44 AM 12,501 USERINT.EXE
11/14/1996 01:44 AM 20,883 UTILINFO.EXE

Does anyone know how I can upgrade the bios to 1.44?

[Bondi]

I don't know how to bypass the battery check on this model, but if you just need sound in DOS games, then there is no need to update the BIOS. You just need sound drivers for DOS.

[jordan1776]

the problem is that im using windows 95. The mwave drivers I found (2.24) only come in 95+DOS compatility and 3.1+DOS. If I try to install the 3.1 drivers the setup complains that i'm not using 3.1. There might be a way to manually install only the DOS portion, but I haven't found it.
I don't care if i can get mwave working in windows 95, I have an external sound card on the LPT port that has a real OPL3 in it, but there is no DOS drivers for it.

[Thinkpad4by3]

Use a power supply to inject ~12-14V into the battery power pins and make it think a battery is present?

[jordan1776]

I saw this thread about batteries viewtopic.php?t=122692 and it doesn't seem like just hooking up power and ground would be recognized as a battery. There is a send pin that nobody figured out what it needs to work.
In other news I did find a DOS driver for mwave 1.01 here http://ps-2.kev009.com/selectpccbbs .The later 2.00 for DOS (the last version to have an exclusive DOS version) looks to be lost to time. I installed it but I hadn't gotten it working in ms-dos mode. It defaults to 0x220 , DMA1, IRQ5. When I startup windows I get a MWAVE 0034 error and continues booting normally as expected. I have my DOS programs on a CF card that isn't recognized in dos normally. I had this program that mounted it but its trialware so if anyone knows a good free loader, recommendations are appreciated.

[Bondi]

I would then install Win 3.11 alongside Win 95 to install the drivers.
Or I guess it is possible to put necessary strings into autoexec.bat and config.sys. Here is a diskette with all original config files for 755CE
http://greyghost.mooo.com/pccbbs/mobiles/755ceori.exe
But I'm not sure if the driver files come unpacked on the audio drivers diskette.

[goldeneagle]

I'd be very careful hooking up power to the DC-DC board, attempting to fool the computer into thinking there's a battery. And as others have mentioned, there are other pins for outputting other data.

I've updated my 755CEs (that weren't updated) using a rebuilt battery, but that's another story.

[hjanzen]

You may have a look at post 25 of following thread

viewtopic.php?f=6&t=6577

Regards,
Hans

[goldeneagle]

That's for a 600. Totally different platform than any of the 755 machines. Though I can't comment on the battery-less updates, as I just updated 2 600E machines (2645-4AU) yesterday using rebuilt batteries (one used cells I got from an X61 pack, the other had its original cells that took a charge up to 4.1V).

As for bricking the machine, I did this on a 755CD, because I had a Lithium Ion battery in it, but without the extra pin on the battery connector. I wasn't waiting more than 5 minutes when my update failed. So when you brick these system boards, the system board counts up your memory, and you just have a cursor afterwards. Nothing else happens. So in theory, you could probably fix it if you know how to do surface mount soldering and put on a flash chip from another system board. For me, it's just cheaper to put in a new system board with a Pentium 75 on it.