Add more than 2 Hard Drives ?

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serrith
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Joined: Tue 23 Jun, 2015 5:36 am

Add more than 2 Hard Drives ?

Post by serrith »

Hello,

Since i'm using Dos 6.22 and thus fat16 my disks fill up way too fast (2GB max).
So i added a second disk ... but some games take +- 500 MB like Quest for Glory 4

Is there a way to add 4 drives ? (primary master/slave, secondary master/slave)
The bios supports it but pcem does not seem to allow it.

Thanks !
startmenu
Posts: 104
Joined: Sat 29 Nov, 2014 7:39 am

Re: Add more than 2 Hard Drives ?

Post by startmenu »

you can create a larger image.
secondary master is reserved for CD-ROM.
serrith
Posts: 19
Joined: Tue 23 Jun, 2015 5:36 am

Re: Add more than 2 Hard Drives ?

Post by serrith »

Well yes technically i can create a maximum drive of 8GB and then partition it to 2GB partitions.

Thats all dos 6.22 seems to support.

Or is there another way ?
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ppgrainbow
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Re: Add more than 2 Hard Drives ?

Post by ppgrainbow »

serrith wrote:Hello,

Since i'm using Dos 6.22 and thus fat16 my disks fill up way too fast (2GB max).
So i added a second disk ... but some games take +- 500 MB like Quest for Glory 4

Is there a way to add 4 drives ? (primary master/slave, secondary master/slave)
The bios supports it but pcem does not seem to allow it.

Thanks !
Later BIOSes starting with SIS-496/497 have support for up to four hard drives (or three hard drives and one CD-ROM). PCem currently emulates up to two hard drives (or one hard drive and one CD-ROM). I tried to post a similar thread regarding support for more than two hard drives, but it seemed that no one cared at this time.

If you have a BIOS ROM with large IDE capacity support (such as the AMI WinBIOS), you can create a partition of up to 16,383 heads, 16 cylinders and 63 sectors per track which totals up to 8,064 MB (7.88 GB). However, MS-DOS will only support up to 1,023 heads, 255 cylinders and 63 sectors per track for a total of 8,025 MB (7.837 GB). Older BIOSes dated before August 1994, such as the AMI 386, can only support IDE hard drives up to 504 MB (1,023 heads, 16 cylinders and 63 sectors per track).

With a maximum partition size of 8,064 MB, the drive has to be split into four partitions per drive (C:, D:, E: and F: for the first hard drive, G:, H:, I: and J: for the second hard drive).

Can someone look into the code to see if there is a way to add support for primary slave and secondary slave IDE hard drives?
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SarahWalker
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Re: Add more than 2 Hard Drives ?

Post by SarahWalker »

The IDE emulation should be able to support hard drives on the secondary channel, it's just never been a priority for me yet.
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SarahWalker
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Re: Add more than 2 Hard Drives ?

Post by SarahWalker »

4 hard drives (3 if CD-ROM is enabled) are now supported as of rev 272.
serrith
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Joined: Tue 23 Jun, 2015 5:36 am

Re: Add more than 2 Hard Drives ?

Post by serrith »

Wow thanks Tom, well like you said it wasn't really a priority, more a nice to have.
Still you seem to jump on it just to satisfy our whims :D sorry but thank you !
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ppgrainbow
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Re: Add more than 2 Hard Drives ?

Post by ppgrainbow »

TomWalker wrote:4 hard drives (3 if CD-ROM is enabled) are now supported as of rev 272.
That's awesome! I can't wait to try out revision 272 of PCem v9 soon! :D

Just curious to ask. Does support for up to 4 hard drive (or 3 hard drives and a CD-ROM if enabled0 work on older BIOSes such as the AMI386, AMI486 and AMI WinBIOS 486?
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SarahWalker
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Re: Add more than 2 Hard Drives ?

Post by SarahWalker »

Well the hardware's there, but those BIOSes only support a single IDE channel so only 2 hard drives will be seen.
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ppgrainbow
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Re: Add more than 2 Hard Drives ?

Post by ppgrainbow »

TomWalker wrote:Well the hardware's there, but those BIOSes only support a single IDE channel so only 2 hard drives will be seen.
Thank you for telling me.
Adomatic
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Re: Add more than 2 Hard Drives ?

Post by Adomatic »

I am sorry for bumping a rather old topic, but there is a DOS utility which enables additional 2 hard drives for 386/486, it was actually designed for real old machines but it works in an emulator just fine. This "4 HDD Utilities" diskette image can be downloaded here: http://oldcomputer.info/hacks/4hdd/index.htm (I apologize if external links are not allowed, I then could attach the image right here, but the link contains some additional useful information), there is a "readme.txt" file which explains how to install it (basically, you need to plug the additional hdds, then initialize them (this will destroy the data, so be careful - but you can create a backup and then just switch images after the initialization, there'll be no difference), and then add the necessary driver startup commands to your config.sys file). I hope this could be helpful for someone.
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