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First post, by DonFuego

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Hi!
Is there a way to break the 504 Mb barrier in DOS 6.22? My BIOS can see up to 8 Gb so I guess I'm looking for some kind of patch / extender that makes DOS handle more than 504 Mb. Or is the answer here DOS 7.x (or other flavour) ?

Reply 2 of 8, by DonFuego

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I can't. FDisk only sees the first 504 Mb.

I'm building the Ultimate 1994 Demo Scene Machine. Specs so far:

* i486DX2/66 * 32 Mb FPM 2-1-1-1/0 WS RAM * Cirrus Logic 5428 VLB 1 Mb (suggestions?)
* Maxtor uMAX II 6 Gb HDD * 3Com 3C509B * SB Pro 16 * GUS Max 1 Mb

Reply 4 of 8, by DonFuego

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DosFreak wrote:

Then it's a BIOS/controller limitation.

Are you sure? I mean BIOS detects the full disk (autodetect with c/h/s values... chs translated i presume). Im pretty sure the limitation is in DOS version X.XX < 7.0 only supporting 6 bit cylinder values? As long as the BIOS supports CHS translation (or Extended CHS) it should handle up to ~ 8 Gb. Or am I completely off the track here? 😀

I'm building the Ultimate 1994 Demo Scene Machine. Specs so far:

* i486DX2/66 * 32 Mb FPM 2-1-1-1/0 WS RAM * Cirrus Logic 5428 VLB 1 Mb (suggestions?)
* Maxtor uMAX II 6 Gb HDD * 3Com 3C509B * SB Pro 16 * GUS Max 1 Mb

Reply 5 of 8, by ratfink

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I have a similar issue on my 486. The bios sees an 8gb drive correctly, and PC DOS 5.02 is running on a 2GB partition, and seems to see all of that.

However, fdisk says the drive is 504mb, though it's let me create another partition of 376mb. I formatted it and yes, it's only 376mb. It's like fdisk picked up the fact that the drive was 25% used, but then only let me create a partition equal to 75% of what it thought there had been in the first place.

[Guess I must have used Win95 or something to set up the 2GB partition.]

Reply 6 of 8, by collector

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Back when I had boxes with real DOS, FDisk from DOS 6.x had no problems with up to 2 GB partitions.

The Sierra Help Pages -- New Sierra Game Installers -- Sierra Game Patches -- New Non-Sierra Game Installers

Reply 8 of 8, by DonFuego

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Thanks! Excellent article. Wish I had found that one years ago 😀

I'm building the Ultimate 1994 Demo Scene Machine. Specs so far:

* i486DX2/66 * 32 Mb FPM 2-1-1-1/0 WS RAM * Cirrus Logic 5428 VLB 1 Mb (suggestions?)
* Maxtor uMAX II 6 Gb HDD * 3Com 3C509B * SB Pro 16 * GUS Max 1 Mb