If you want to connect it using the same ribbon as the old one - you have set it to slave.
One IDE channel allows to connect two devices. One must be set as master, second as slave. As simple as that !

Some of the IDE drives needs different jumper settings for master, and different for 'single drive' (only one drive connected to IDE channel).
But it should be described on the drive itself.

There is also third possibility. Set both drives to "cable select" and connect those to one IDE channel. They should configure itself for master/slave.
But it is least compatible option.

Thanks zyga64!

I have another question, to format the 20gb hd I need to do something special? I mean format with the cd on windosw 98 for example create a dos primary partition and then I need to do something else?

This hd comes from antoher pc with windows xp

Thanks again!

Windows 98 will recognize new drive (even if it is not detected by BIOS, you can overcome BIOS limitation 😀 but not file system on it.
Hard drive needs to be partitioned for Windows 98 first, because Windows XP uses NTFS file system which can not be used by Windows 98 by default.

You can do it after connecting it to Windows 98 computer (it's the fastest way).
1.) Run commandline (press Windows key + R, and type command.com).
2.) type 'fdisk' and press enter.
3.) Confirm you want to use 'large disks' - it allows you to create Fat32 partitions, if you decide not to use 'large disk', you will be able to create partitions with size up to 8GB (fat16 limitation).
4.) change active hard disk to the new one, display its structure, ensure it's the correct hard drive
5.) delete all partition from it (first all 'logical' inside 'extended' partition, than extended partition itself, next 'primary' partition) <- pay attention not to use old disk, you can lose all data !!!!
6.) Create 'primary' partition with max size
7.) Exit fdisk, close command.com window, reboot computer
.
.
.
😎. After reboot, Open "My computer", right-click on new created partition and choose 'Format', check 'use quick formatting'.

That's all !

You can do it in MS-DOS mode prior to loading windows GUI, but it will be way slower.

[Edit] Just the grammar, not the content.

[..]because Windows XP uses NTFS file system which can not be used by Windows 98 by default.

Yes, by now it does use NTFS. In early 2000, Windows XP was often installed on FAT32, though.
Windows XP supported both FAT32/NTFS for installation..
Otherwise, upgrading from Windows 9x to XP wouldn't have been possible in first place. 😉

thanks a lot zyga64!

Win95 OSR 2.5 should be able to do FAT32 20gb with that second drive, the win98 part isn't neccessary. It's already right on the edge of stock Win95's CPU support though. 😉

zyga64 wrote on 2022-10-20, 08:27:

There is also third possibility. Set both drives to "cable select" and connect those to one IDE channel. They should configure itself for master/slave.
But it is least compatible option.

IDE cables intended for Cable Select mode operation have a line cut, you can tell this as a pinhole when you hold it up to the light.

leileilol wrote on 2022-10-20, 16:46:

Win95 OSR 2.5 should be able to do FAT32 20gb with that second drive, the win98 part isn't neccessary. It's already right on the edge of stock Win95's CPU support though. 😉

You are of course right. Looks like I didn't read first post carefully. For me Pentium II means Windows 98. Windows 95 is just too... plain visually (for me).
But besides that, my point was to do partitioning after starting windows GUI, in plain Ms-dos mode it would take ages...

Everything it works thanks ziga64! Yeah I know windows 98 is a better option for this machine, but I grow up with win95 in this machine and another 486 its pure nostalgia, but i want build windows 98 too in the future 😀