VOGONS


First post, by kikendo

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I'm resurrecting a Gateway 2000 386SX/25 and I would like to get a hard drive for it since the one it came with (~80MB) is dead.
I read about the several BIOS limits for IDE devices, but what I didn't find is how to recognize which BIOS I have in order to be able to buy the largest replacement I possibly can.

The machine is from ~1991 and my only guess is that a 512MB one would be fine, but if I can put in more it'd be great, since 512MB will not hold that much when I start installing CD-ROM games.
BIOS chip is marked as: Quadtel 286/SX 120594

Thanks in advance for any info you can provide!

Reply 1 of 16, by Jo22

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kikendo wrote on 2020-06-11, 14:49:
I'm resurrecting a Gateway 2000 386SX/25 and I would like to get a hard drive for it since the one it came with (~80MB) is dead. […]
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I'm resurrecting a Gateway 2000 386SX/25 and I would like to get a hard drive for it since the one it came with (~80MB) is dead.
I read about the several BIOS limits for IDE devices, but what I didn't find is how to recognize which BIOS I have in order to be able to buy the largest replacement I possibly can.

The machine is from ~1991 and my only guess is that a 512MB one would be fine, but if I can put in more it'd be great, since 512MB will not hold that much when I start installing CD-ROM games.
BIOS chip is marked as: Quadtel 286/SX 120594

Thanks in advance for any info you can provide!

Hi! And congrats for your 100. posting! 😁

Well, I don't know for sure. The "problem" is CHS limit / max. support via normal int13h.
Some BIOSes allowed higher values for normal int13h, but were causing compatibility issues.
That's why extended int13h was introduced (with PS/2 line of PCs ?), but DOS doesn't use that extended int13h..

Edit: Related to this might be the 4096 cylinder limit.
"Summary: Some BIOS-- developed before the second half of 1996-- limited the physical drive
Cylinders to a 12 bit binary number, which supports a maximum of 4096 Cylinders or Tracks. (CMOS values 0 to 4095)"

See http://web.allensmith.net/Storage/HDDlimit/4096.htm

So it's hard to say. If you like to use higher capacity drives, don't worry.. The ~504MB limit is not a hardware limit.
Just use XTIDE BIOS on a network card or use a DDO (Dynamic Drive Overlay) and the IDE ports on you 286/386 can support 8GB just fine.

Anyway, if you like to find out the HDD limit, just run FDISk and see how much it will try to allocate for your drive.
If something goes wrong, you can clear the card / HDD using S0Kill.

PS: DOS 5+ can use more than 2GB (per partition) on FAT16 if patched. In Virtual PC, for example, the normal int13h allows for more than ~504MB. 😉

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Re: Intel VS440FX refuses to boot DOS 6.22 from detected SSD

Some links:
Re: 512mb CF card cylinder values ?
Re: BIOS Limitations & Large Hard Drives
Re: IDE disk-on-module + 386

Edit: I forgot to mention.. You can use "fake CHS" values just fine. That's how things were done before LBA.
Just use a combination of cylinders/heads/sectors that's within the limits of your HDD.
As long as you don't exceed the maximum capacity of your HDD, everything will be fine.

My father and me did this on my 286 in the 90s.
HDD was an 80MB Conner drive, but CMOS setup had a 40MB limit (no type 47).

If you're afraid of data corruption, simply run CheckIt! (v3 or v4) and let it do the HDD test.
If no errors show up, things should be fine! 😁

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Last edited by Jo22 on 2020-06-12, 05:49. Edited 2 times in total.

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Reply 2 of 16, by konc

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99% for a 1991 386 computer the limit is the classic 1024cyl/16heads/63sectors=528MB. The rest 1% is even smaller .
You can always use some dynamic drive overlay software (DDO) or the XT-IDE BIOS if you want a larger HDD, but honestly it's not really needed unless you want to install everything that runs on this PC.
Also, cdrom games? very few will run well enough on an SX/25 (and I assume cacheless)

Reply 3 of 16, by Jo22

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konc wrote on 2020-06-11, 17:43:

99% for a 1991 386 computer the limit is the classic 1024cyl/16heads/63sectors=528MB. The rest 1% is even smaller .
You can always use some dynamic drive overlay software (DDO) or the XT-IDE BIOS if you want a larger HDD, but honestly it's not really needed unless you want to install everything that runs on this PC.
Also, cdrom games? very few will run well enough on an SX/25 (and I assume cacheless)

Okay, 504MiB (Mebibyte), actually*.. 😉

1024x63x16x512 = 5284822304 Bytes

5284822304 Bytes divided by 1024 = 516096 KiB (Kibibyte)
516096 KiB divided by 1024 = 504 MiB

(Assuming we go by the new SI compliant naming scheme,
in which Kilobytes use a conversion number of 1000 instead of 1024.
Or, if we follow the hard disk manufacturers "tradition" of always using 1000.
That has of course, nothing to do with the fact that they can sell drives with lesser capacity as "bigger" drives. 😉 )

"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel

//My video channel//

Reply 4 of 16, by darry

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Jo22 wrote on 2020-06-11, 19:17:
Okay, 504MiB (Mebibyte), actually*.. ;) […]
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konc wrote on 2020-06-11, 17:43:

99% for a 1991 386 computer the limit is the classic 1024cyl/16heads/63sectors=528MB. The rest 1% is even smaller .
You can always use some dynamic drive overlay software (DDO) or the XT-IDE BIOS if you want a larger HDD, but honestly it's not really needed unless you want to install everything that runs on this PC.
Also, cdrom games? very few will run well enough on an SX/25 (and I assume cacheless)

Okay, 504MiB (Mebibyte), actually*.. 😉

1024x63x16x512 = 5284822304 Bytes

5284822304 Bytes divided by 1024 = 516096 KiB (Kibibyte)
516096 KiB divided by 1024 = 504 MiB

(Assuming we go by the new SI compliant naming scheme,
in which Kilobytes use a conversion number of 1000 instead of 1024.
Or, if we follow the hard disk manufacturers "tradition" of always using 1000.
That has of course, nothing to do with the fact that they can sell drives with lesser capacity as "bigger" drives. 😉 )

If you want bigger drives, XTIDE is probably your best bet .

EDIT: Just noticed that it was mentioned before, sorry . Anyway I agree .

Reply 5 of 16, by kikendo

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Thank you all for the replies so far. Very educational. You see, I only entered the PC game back in the day at the Pentium level. I never had to mess with anything older.

konc wrote on 2020-06-11, 17:43:

99% for a 1991 386 computer the limit is the classic 1024cyl/16heads/63sectors=528MB. The rest 1% is even smaller .
You can always use some dynamic drive overlay software (DDO) or the XT-IDE BIOS if you want a larger HDD, but honestly it's not really needed unless you want to install everything that runs on this PC.

I have no idea what a DDO is or XT-IDE
I would like to use, tops, a 2GB CF card on this. But if I have to go 512MB so be it.

Also, cdrom games? very few will run well enough on an SX/25 (and I assume cacheless)

I thought a 386 was apt for most of the early stuff? Stuff like Wing Commander, Talkie adventures, etc. I don't want to run X-Wing on it or anything. There were a lot of pre 1993 CD-ROM titles I'd like to explore. I remember playing them at a friend's house and he didn't get a 486 until much much later.

[edit] Check this list out, for example: https://www.mobygames.com/browse/games/dos/ti … 21/ti,518/1991/

Reply 7 of 16, by Mister Xiado

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My Hewlett Packard Vectra 486 66/XM D2933A

Intel 486DX2 66 (overdrive)
32MB 60 PIN SIMM RAM (4x8MB)
BIOS: W.04.03 HP VECTRA PC
SoundBlaster Vibra16 CT4170
Trident 7120?
Linksys LNE2000T ISA Ethernet NIC

supported a 1GB HDD without issue, and didn't balk at a 2GB CompactFlash card. I have a Pentium system

Shuttle HOT-569 v2A59IH2H with Intel Triton 82430TX chipset
Award Modular BIOS v4.51PG
Intel Pentium MMX 166 revision 0543h
128MB DIMM (2X 64MB)
Sound Blaster 16 CT2770
Trident GUI9660XGi/968x/938x
Linksys LNE100TX

that didn't mind a 4GB CompactFlash card, but I never tested a traditional HDD with it.

My first computer,

Biostar M5ATB
AMI BIOS 2A5KIB09C-00
AMD K6-2 500 (@300 MHz)
SoundBlaster Vibra CT4XXX
Nvidia GeForce MX4000 128MB (Jaton Video-208PCI-128TV)
Linksys LNE100TX

has a 20GB HDD in it, but cannot recognize the 40GB and 80GB drives I have. The system tries to detect them, and even when given an hour, never completes.

The only way to be absolutely certain is to just try stuff, since the only computer I've ever had that would balk at say, a 740MB drive, MIGHT have been a 386 I used to have, but I didn't have any spare drives to test in it before someone destroyed it.

b_ldnt2.gif - Where it's always 1995.
Icons, wallpapers, and typical Oldternet nonsense.

Reply 8 of 16, by Pierre32

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Here's my experience in my 386 (Asus ISA-386C mobo), and the same for my 486 (Presario 425). I'm not running any overlay software, and as expected FDISK will only format a drive up to ~500MB.

In the 386, the C: drive is an 8GB HDD. I entered the drive geometry in BIOS, where it accepted settings for an 8GB drive. Then I did a fresh DOS 6.21 install including format, and CHKDSK now reports it as a 1.5GB drive.

Between both machines I share a parallel port CF reader with a 2GB card. Again, FDISK would only format this as a 500MB card. However using the card reader's own setup utility, I can format the card to its full capacity, and CHKDSK confirms it sees 2GB.

Reply 9 of 16, by jakethompson1

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kikendo:

Can you poke around in your BIOS setup in the screen where it lets you manually enter parameters for a hard drive ("user type"). Do you see any options relating to LBA, LARGE, or the like?

Reply 10 of 16, by darry

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jakethompson1 wrote on 2020-06-11, 23:36:

kikendo:

Can you poke around in your BIOS setup in the screen where it lets you manually enter parameters for a hard drive ("user type"). Do you see any options relating to LBA, LARGE, or the like?

On a machine from 1991, I would not bet on it .

Reply 11 of 16, by Deksor

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LBA was invented in 1994, so you definitely won't see that on a stock 1991 machine.

Trying to identify old hardware ? Visit Ultimate Hardware 2019 - Project's thread The Ultimate Hardware 2019 (UH19) project- a stason.org/TH99
alternative

Reply 12 of 16, by jakethompson1

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darry wrote on 2020-06-11, 23:46:

On a machine from 1991, I would not bet on it .

This is vaguely reminding me of something I dealt with on a Compaq Deskpro 386/25 or the like about 20 years ago when that was just an "old computer" and not a retrocomputer. I remember that there was no "user type" option in the BIOS, but some of the types it had were like 600MB or so, definitely over the 504/528MB limit. I'm wondering how that worked. Maybe the number of cylinders was still 1024 and it was just more than 16 heads? Obviously this was pre-LBA

Reply 13 of 16, by jakethompson1

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Deksor wrote on 2020-06-12, 01:13:

LBA was invented in 1994, so you definitely won't see that on a stock 1991 machine.

Here we go, adding on to my above comment: http://www.thecomputerarchive.com/Compu ... (1989).pdf
Note on page 2 that a 650MB hard drive was available. How the heck did they manage that in 1989? With 1024 cyls but more heads? Specially patched Compaq DOS? I don't think it was SCSI or anything special.

Reply 14 of 16, by Deksor

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I've seen that on my compaq deskpro 386s/20n too. Now LBA is on the BIOS side, for hard drives themselves, I believe LBA existing or not doesn't really matter.

Trying to identify old hardware ? Visit Ultimate Hardware 2019 - Project's thread The Ultimate Hardware 2019 (UH19) project- a stason.org/TH99
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Reply 15 of 16, by darry

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jakethompson1 wrote on 2020-06-12, 01:19:
Deksor wrote on 2020-06-12, 01:13:

LBA was invented in 1994, so you definitely won't see that on a stock 1991 machine.

With 1024 cyls but more heads?

Precisely . With something called CHS geometry translation . LBA came about later .

https://www.informit.com/articles/article.asp … 31238&seqNum=14

Reply 16 of 16, by konc

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kikendo wrote on 2020-06-11, 19:48:

I thought a 386 was apt for most of the early stuff? Stuff like Wing Commander, Talkie adventures, etc. I don't want to run X-Wing on it or anything. There were a lot of pre 1993 CD-ROM titles I'd like to explore. I remember playing them at a friend's house and he didn't get a 486 until much much later.

[edit] Check this list out, for example: https://www.mobygames.com/browse/games/dos/ti … 21/ti,518/1991/

Almost all games except maybe a few that I don't know them were originally released on floppy disks and they only exist on this list because they had a later cdrom re-release. 1991 was too early for cd-rom games, I believe it wasn't until 1993 that a cdrom release became common. But even with this consideration I agree, 500MB are not enough if you really want to install a lot of games. Just keep in mind that many games that you now think will work fine, they won't. I'm not saying they won't run, but even talkie adventures won't be fun on an SX/25 (especially if it's cacheless, which most probably is the case)