VOGONS

Windows 95 and the 504MB Limit

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First post, by maxtherabbit

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Let's say you've got Win95B installed on a system with an old BIOS that has no int13 extensions or CHS translation.
Let's say you installed it on a FAT16 primary partition on the boot drive that only uses 1024 cylinders and is completely accessible by the BIOS.

If you also had an extended partition on there *beyond* 1024 cylinders, would 95 see it once booted up and ESDI_506.PDR is loaded?

Reply 1 of 2, by weedeewee

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I think the answer is yes.
I recall using this trick in linux many times.
Though there might be some gotcha's lurking.

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Reply 2 of 2, by maxtherabbit

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Well I tried it myself, it does in fact work.

Made primary partition in DOS using 100% (which was only the 504MB DOS can see). Installed 95B on that partition. Then stuck a XUB ROM in temporarily. Booted from a floppy and used FDISK to create an extended partition using the remaining space. Removed XUB ROM.

Now DOS only sees the primary partition and when the 95 GUI is loaded I have access to both. Seems to work perfectly from the testing I've done thus far.

As a side note, I did some perf tests with and without XUB. Getting about 1.23MB/sec reads with the built in BIOS routines and about 1.5MB/sec using the 386 build of XUB. Interesting that it is an improvement, but not substantial enough to make me keep it permanently.

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