To get into BIOS:
Hold down ESC during POST, then press [F1] at the prompt.
I've got a T1960CS that I still use. The color does have a sort of washed-out look, it's the technology of the era rather than anything wrong with the display. My T2150CDT from just about 18 months later has a much nicer display.
I'll tell you, though, even that "washed out" T1960 display looked like "The Fuuuutuuuure
" when I first fired it up. My co-workers gathered around to watch the powering-up ceremony and oohed and ahhed appreciatively.
To open it up, remove the screws on the bottom. I recall there's one screw hidden under a tab on the top of the keyboard panel, but you don't need to touch it to open the bottom of the case to get at the hard disk. What it's for is obvious once you get inside.
It's not a good Win95 machine, I even downgraded from Win95 back to 3.11 on my 2150CDT, and it has 32MB of RAM (my T1960 has 8MB.) If you must do Windows, I'd strongly suggest sticking with 3.0 or 3.11 (better networking under Windows for Workgroups, but you'll need a PCMCIA ethernet card, and drivers, and a full bottle of your favorite headache treatment.)
Personally I run mine under DOS 6.21 with the Toshiba extensions (just power management for the 1900 series) and do all my I/O over PCMCIA modem, serial and parallel ports. I had Ether in it once, but the drivers kept going wonky on me so I finally just pulled it out and wiped the drivers ( I had had a stable ethernet card once, but noooo, I had to yank it and put in a newer, shinier one for some reason and that's the one that the drivers went bonkers once per fortnight.)
I have a book...somewhere. I gave the system to my daughter for about a year, and after it had been superseded for her I got it back, but not all at once. So the book has been separated from the system. When it turns up I'll see if I can scan some of the significant parts.
RAM: The stuff that won't work won't even look right. If they actually have it in stock (you often won't find out if the company really has it until after you place an order, I think they take orders then see if they can get any themselves) then it'll probably be refurb or NOS. Make sure of the supplier's return terms before ordering, and be comfortable with them.
The system runs very well under DOS with the installed 4MB. It'll even run DOOM. You can expand it up to 20MB. The largest expansion it will take is 16MB, some places offer 32MB cards, they'll either not function or only give you 16MB. In both cases my experience is that they don't damage the computer, but they won't work. There was another model in a closely related line that would take these, and they often get listed for the 1900 series, too.
If I recall correctly, the difference between the 1910 and the 1960 is processor speed and not much else. Going by memory, the 1910 is 33MHz and the 1960 is 66MHz.
Removing RAM: With the system off, and the display open, there's a door that covers the RAM slot on the right edge of the keyboard area, near the display. Flip it open, inside is a black piece of kapton tape above the RAM module. Pull it out then gently but _firmly_ pull it to the side of the unit to get the RAM module out. Don't use a tool on it (pliers, etc.), because that might tear the kapton. It's tough, but not that tough.
To insert RAM, place the module in with the printed side up, arrow pointing in toward the computer. It sits beneath the kapton tape, if you try to put it on top of the tape, the tape will keep it from going in. Slide the module in until it sits nearly flush with the edge of the case above it. System power off, through the entire procedure, of course. Put the cover back down over the unit. It will click shut without being forced if the RAM module is seated properly.
Hard disks: I have used hard disks other than the original sizes in my T1960 and T2150. Again, this is from memory, but I recall the 1960 as taking anything up to 520MB, and the 2150 as taking anything up to 2GB. I remember the Toshiba BIOS as not being a limited laptop BIOS, but behaving like a full desktop BIOS. Our company was buying them as desktop replacement systems for folks who traveled and gave presentations outside the company. They were the only laptop approved by our company as a full desktop replacement (aside from the HP-UX laptop machines, which were approved for replacing a Unix desktop at the time.)
At any rate, I used to keep a box of hard disks I swapped in and out of both systems, depending on their current use (different OSes, development environments, etc.) These disks weren't specially selected, they were pulls from random laptops that'd been scrapped out (non-Toshiba, as you could hardly kill a Toshiba with a 12 guage shotgun and a dump truck.
) They were different sizes. I recall using drives up to 450MB in the T1960. Disks of 1GB and larger I used in the T2150.
Whether a larger drive will work as a lesser capacity disk will depend on the disk's configuration of heads and platters in part. You can also try to use one of the add on programs from the time that will remap the drive from its physical configuration to a logical one.
The back feet on the bottom of the case will click in and out to hold the machine at a better angle for typing for some people. I usually leave mine flat, but some folks prefer the angle the feet give when extended.
The door to the immediate right of the keyboard on the base is where the click-on trackmouse goes. It's a sweet little thing. Unfortunately, I lost mine about ten years ago. I really miss it. If anyone happened to pick one up at USENIX in 1999 or 2000, that was probably mine. I can't recall which year I lost it, any more. I'll pay a small ransom or trade some hardware for it. :D