Possible? Sure. Practical and does anyone have the time or inclination, probably not. If you’re offering, go for it and please share. There will be a few people who will be grateful for your effort.

mikeyp wrote on 2022-06-21, 16:28:

Possible? Sure. Practical and does anyone have the time or inclination, probably not. If you’re offering, go for it and please share. There will be a few people who will be grateful for your effort.

I have only extracted the bios, placed a socket to be able to reinstall it on the motherboard and I have read the flash memory to get its porogram. I don't know if it can be uploaded to the forum...

I just don't know how to modify it... but if someone helps me I'll do the necessary tests to put everything in the 386 and check if it works. I would be happy to post it here to help the community.
If someone wants to see the bios with a hexadecimal editor I can send it to them by email or tell me how to publish it in the forum.
Kind regards from Spain
My e-mail z7upower@yahoo.es

The T2000sx BIOS unfortunately doesn't work in PCem. If someone could get it (or one of these other BIOSes) to run in PCem or similar, I'd be more interested in looking at this as I don't have any of the hardware. At https://github.com/biketronic/T2000SXe-BIOS the author figured out the ATA IDENTIFY check, which I also was looking at in the BIOS image, but I have no idea how he figured out the SETUP program to unlock the ability to flip between drives.

mikeyp wrote on 2022-02-06, 23:17:

You’re missing the point. Please read the whole thread before replying. The issue is that these laptops only allow the specific models whitelisted in the bios. Ergo we need to fake this ID in the firmware of the drive connected or the bios will reject it and merely say no drive connected.

TronadaSport wrote on 2022-06-21, 19:31:

I have only extracted the bios, placed a socket to be able to reinstall it on the motherboard and I have read the flash memory t […]
Show full quote

I have only extracted the bios, placed a socket to be able to reinstall it on the motherboard and I have read the flash memory to get its porogram. I don't know if it can be uploaded to the forum...

I just don't know how to modify it... but if someone helps me I'll do the necessary tests to put everything in the 386 and check if it works. I would be happy to post it here to help the community.
If someone wants to see the bios with a hexadecimal editor I can send it to them by email or tell me how to publish it in the forum.
Kind regards from Spain
My e-mail z7upower@yahoo.es

Could one of you who has dumped the BIOS post it? I think I see how to fix the T1800/T1850 BIOSes but I have no real Toshiba hardware to test on.

Let's see if you can download the bios from here, if someone knows how to upload it directly to the forum, do it.

https://drive.google.com/file/d/17oBbn39YTnjy … iew?usp=sharing

If you have progress or want to try the modified bios send it back to me: z7upower@yahoo.es

TronadaSport wrote on 2022-06-27, 16:05:

Let's see if you can download the bios from here, if someone knows how to upload it directly to the forum, do it.

https://drive.google.com/file/d/17oBbn39YTnjy … iew?usp=sharing

If you have progress or want to try the modified bios send it back to me: z7upower@yahoo.es

I also have the same problem with T1850, both FDD and HDD are dead (FDD could be fixed with new belt) and after spending 2 days with various CF cards, I stumbled on this forum 😀
I am eagerly looking forward to any progress here...
Regards, Bojan

Bojan wrote on 2023-02-06, 01:50:

I also have the same problem with T1850, both FDD and HDD are dead (FDD could be fixed with new belt) and after spending 2 days […]
Show full quote

TronadaSport wrote on 2022-06-27, 16:05:

Let's see if you can download the bios from here, if someone knows how to upload it directly to the forum, do it.

https://drive.google.com/file/d/17oBbn39YTnjy … iew?usp=sharing

If you have progress or want to try the modified bios send it back to me: z7upower@yahoo.es

I also have the same problem with T1850, both FDD and HDD are dead (FDD could be fixed with new belt) and after spending 2 days with various CF cards, I stumbled on this forum 😀
I am eagerly looking forward to any progress here...
Regards, Bojan

I think I have a T1850 BIOS ready to go that accepts all drives as 1024/16/63, but couldn't find anyone to test it. The issue is if it doesn't work, it will brick your system, and I believe these have soldered-in BIOS chips so you would need a hardware solution at that point.

jakethompson1 wrote on 2023-02-08, 23:15:

I think I have a T1850 BIOS ready to go that accepts all drives as 1024/16/63, but couldn't find anyone to test it. The issue is if it doesn't work, it will brick your system, and I believe these have soldered-in BIOS chips so you would need a hardware solution at that point.

I haven’t forgotten. Just don’t have the time sadly to be disassembling the machine to get a working floppy drive hooked up or if it fails, getting out the hot air soldering stuff and removing the chip.

Any news?
If someone send me modified BIOS, I may find a courage to attempt to remove EEPROM and reprogram it.

I had modified the BIOS of my T3100SX to replace the parameters of an hardcoded HDD with the ones from a CF card, here's the post I had made Toshiba T3100SX Modified BIOS / Help with its IDE

In that T1850 binary the HDD parameters start at offset 0x84E8 and it seems to be only one set (so no "alternate" like in my T3100SX). The first is CP2044:

6702 04 0000FFFF0000000000 6702 11 07

615 cylinders (0x0267), 4 heads, landing zone 615, 17 sectors (0x11)

I don't know what that last byte is/means.

This is the entire HDD table matched as best as I could:

1CP2024:		6702 04 0000FFFF0000000000 6702 11 07
2JD-E2825P:	4502 02 0000FFFF0000000000 4502 24 07
3CP2044:		D403 05 0000FFFF0000000000 D403 11 04
4JD-E2850P	1703 03 0000FFFF0000000000 1703 23 07
5CP2034:		9B01 04 0000FFFF0000000000 9B01 26 04
6CP2064:		3703 04 0000FFFF0000000000 3703 26 04
7MK1122FC:	DC03 05 0000FFFF0000000000 DC03 11 04
8??????????:	6702 10 0000FFFF0000000000 6702 11 07
9MK2024FC:	DC03 0A 0000FFFF0000000000 DC03 11 04
10CP2088 (?):	2502 08 0000FFFF0000000000 2502 26 04
11CP2124:		FA02 08 0000FFFF0000000000 FA02 27 04
12MK2124FC:	A603 10 0000FFFF0000000000 A603 11 04
13WD AB140:	D403 05 0000FFFF0000000000 D403 11 04
14WD AH260:	0004 07 0000FFFF0000000000 0004 11 04
15WD AH280:	D403 0A 0000FFFF0000000000 D403 11 04
16CP2084:		2402 08 0000FFFF0000000000 2402 26 04
17JD-E2130M:	1A02 08 0000FFFF0000000000 1A02 3B 04

To add support for a CF card get its CHS parameters, translate them to hex to match and replace an existing drive with those. Then adjust the corresponding strings for name (around 0x888A) and capacity (around 0x375E) to match the CF card (don't exceed the preexisting number of bytes for either), fix the checksum and voilà.

Other IDE Toshiba laptops (for example T1200XE) have the parameters encoded the same way and are very easy to find and the same procedure applies