AMI 486 w/CS4031 chipset (CT486) and Bochs BIOS

[ppgrainbow]

Currently, MAME has working support for the driver known as CT486. It is another AMI 486 clone, but it has the CS4031 chipset and has the BIOS date of 1992-07-07. Plus, it's the first 486-based machine to have XTIDE support for up to 8 hard disks. In order to use XTIDE, drive C and D hard drive types have to be set to None.

Also, I've added Bochs BIOS which can be found in Bochs and older versions of QEMU respectively. Bochs is the only BIOS that I know that has support for up to eight hard disks (4 IDE channels) and it uses the IDT Winchip/Pentium processor. Bochs BIOS has to be place on the bottom of the machine configuration list in Configure PCem dialog. In order to use the Bochs BIOS, the "BIOS-bochs-legacy" or any Bochs related 64 KB ROM has to be renamed to "bochs.bin"

Please test my patches and test support for up to 8 hard drives to see how it works! Thanks!

I forgot to mention that the Bochs BIOS ROM uses the PS/2 mouse, so you can get the emulated PS/2 mouse working on the get go.

CT486_Bochs.zip

(1.63 KiB) Downloaded 689 times

[nerd73]

Currently, MAME has working support for the driver known as CT486. It is another AMI 486 clone, but it has the CS4031 chipset and has the BIOS date of 1992-07-07. Plus, it's the first 486-based machine to have XTIDE support for up to 8 hard disks. In order to use XTIDE, drive C and D hard drive types have to be set to None.

Also, I've added Bochs BIOS which can be found in Bochs and older versions of QEMU respectively. Bochs is the only BIOS that I know that has support for up to eight hard disks (4 IDE channels) and it uses the IDT Winchip/Pentium processor. Bochs BIOS has to be place on the bottom of the machine configuration list in Configure PCem dialog. In order to use the Bochs BIOS, the "BIOS-bochs-legacy" or any Bochs related 64 KB ROM has to be renamed to "bochs.bin"

Please test my patches and test support for up to 8 hard drives to see how it works! Thanks!

I forgot to mention that the Bochs BIOS ROM uses the PS/2 mouse, so you can get the emulated PS/2 mouse working on the get go.

CT486_Bochs.zip

Where's the CS4031 emulation?

[ppgrainbow]

Where's the CS4031 emulation?

As far as I know, it's the part of the ct486 driver that is found in MAME. I don't think that the CS4031 emulation has been emulated at this time. But other than that, the machine works as is.

[nerd73]

Where's the CS4031 emulation?

As far as I know, it's the part of the ct486 driver that is found in MAME. I don't think that the CS4031 emulation has been emulated at this time. But other than that, the machine works as is.

Why would you need more than 4 HDDs or even want the Bochs BIOS?

[ppgrainbow]

Where's the CS4031 emulation?

As far as I know, it's the part of the ct486 driver that is found in MAME. I don't think that the CS4031 emulation has been emulated at this time. But other than that, the machine works as is.

Why would you need more than 4 HDDs or even want the Bochs BIOS?

As I said before, it's experimental and untested. Bochs and XTIDE Universal BIOS both have the capability of supporting more than four IDE hard drives (10 hard drives max for XTIDE, 8 hard drives for Bochs) where as most BIOSes can't support more than two to four IDE hard drives (one to two IDE connectors). Plus, Bochs is a open-sourced BIOS that has been even used in the SPC/AT emulator and in older versions of Qemu.

Right now, these patches (including the support for up to eight IDE hard drives using the Bochs BIOS and XTIDE Universal BIOS) that I implemented earlier today are experimental and have not be tested to see if they will work or not. And if for some reason, you encounter any errors, please point them out as well as the code.

[Battler]

Well, the Bochs BIOS is not of a real chipset, and is therefore outside PCem's scope as PCem aims to emulate real hardware. I also seen no use in having so many hard disks. Even with 4 hard disks, you reach 4*8 = 32 GB total storage, which is more than enough storage, especially considering what was common in the era of the chipsets being emulated.

[te_lanus]

Where's the CS4031 emulation?

As far as I know, it's the part of the ct486 driver that is found in MAME. I don't think that the CS4031 emulation has been emulated at this time. But other than that, the machine works as is.

Why would you need more than 4 HDDs or even want the Bochs BIOS?

Think the only Time I've seen a older PC with more than 4 drives, was a 386 Server, that I worked on 6 or 7 years ago (it had 6 hdds and two 386dx/20 cpu's). I think so far I only worked on two "recent" pc's with more than 4 hdds, most Motherboards I've seen here has 4 hdd (sata or IDE) slot's. My otherhalf's pc has 8 hdd slots (4 Sata & 4 IDE), but you can only use 4 at any given time.

For the Bochs bios, I can't see why we need it.

[ppgrainbow]

Well, the Bochs BIOS is not of a real chipset, and is therefore outside PCem's scope as PCem aims to emulate real hardware. I also seen no use in having so many hard disks. Even with 4 hard disks, you reach 4*8 = 32 GB total storage, which is more than enough storage, especially considering what was common in the era of the chipsets being emulated.

That's true that I forgot to mention that Bochs is indeed not a real chipset. In the real BIOSes that are emulated, the absolute maximum amount of total storage is 4 * 8,064 = 32,256 MB (4 * 8,025 MB for MS-DOS for a total of 32,100 MB). The Award SiS 496/497 BIOS does not properly support hard disks larger than 2,016 MB and older BIOS do not even support more than two hard disks that are larger than 504 MB each.

As it is not officially part of the patch and if you want to use the Bochs BIOS, you're on your own. If it breaks, you're out of luck. Infact, it is possible to replace the BIOSes that emulate real hardware with the Bochs BIOS ROM, but this experiment is NOT supported by PCem and may not work 100% correctly.

[ppgrainbow]

Think the only Time I've seen a older PC with more than 4 drives, was a 386 Server, that I worked on 6 or 7 years ago (it had 6 hdds and two 386dx/20 cpu's). I think so far I only worked on two "recent" pc's with more than 4 hdds, most Motherboards I've seen here has 4 hdd (sata or IDE) slot's. My otherhalf's pc has 8 hdd slots (4 Sata & 4 IDE), but you can only use 4 at any given time.

For the Bochs bios, I can't see why we need it.

A 386-based server with six hard drives? Wow!

As far as I know, Bochs has already been used in other emulators such as SPC/AT and in older versions of Qemu. Both Bochs and the XTIDE Universal BIOS have the capability to support more than four hard drives even if its not officially supported by PCem.

[Battler]

The Award SiS 496/497 BIOS does not properly support hard disks larger than 2,016 MB and older BIOS do not even support more than two hard disks that are larger than 504 MB each.

Well, 4*2 = 8 GB. Why would you even need more than than on a 486? Especially considering that even 2 GB was a lot for a 486. The one I had, had a 249 MB hard disk. And everything fitted quite fine onto it. And you need even less space for software designed for 386 and earlier, and when you get early enough, most software is designed to fit onto, say, 360 kB floppies.

[ppgrainbow]

The Award SiS 496/497 BIOS does not properly support hard disks larger than 2,016 MB and older BIOS do not even support more than two hard disks that are larger than 504 MB each.

Well, 4*2 = 8 GB. Why would you even need more than than on a 486? Especially considering that even 2 GB was a lot for a 486. The one I had, had a 249 MB hard disk. And everything fitted quite fine onto it. And you need even less space for software designed for 386 and earlier, and when you get early enough, most software is designed to fit onto, say, 360 kB floppies.

Probably a lot of software to install on that machine perhaps. With only physical CD-ROM support in PCem right now, I instead have to use ImDisk to extract the ZIP files intro the hard disk image and then install the software from there. With hard drives larger than 504 MB on BIOS that support buggy LBA features, you may eventually experience data corruption as a consequence.

[SarahWalker]

The Award SiS 496/497 BIOS does not properly support hard disks larger than 2,016 MB and older BIOS do not even support more than two hard disks that are larger than 504 MB each.

Well, 4*2 = 8 GB. Why would you even need more than than on a 486? Especially considering that even 2 GB was a lot for a 486. The one I had, had a 249 MB hard disk. And everything fitted quite fine onto it. And you need even less space for software designed for 386 and earlier, and when you get early enough, most software is designed to fit onto, say, 360 kB floppies.

Probably a lot of software to install on that machine perhaps. With only physical CD-ROM support in PCem right now

Just use a virtual CD drive, please!

[ppgrainbow]

That's what I'm talking about...a virtual CD drive.

Edit: Oops, I think that I misunderstood you. I can mount ISOs using ImDisk and should be using them when I enable CD-ROM support in PCem.

[te_lanus]

That's what I'm talking about...a virtual CD drive.

Think you might have misunderstood Tom. He's talking of running Something like Daemon Tools, Virtual CloneDrive or Virtual CD-ROM

[ppgrainbow]

That's what I'm talking about...a virtual CD drive.

Think you might have misunderstood Tom. He's talking of running Something like Daemon Tools, Virtual CloneDrive or Virtual CD-ROM

Sorry that I miss understood Tom. Like I said before, I use IMdisk to mount ISOs...so, it should be all good to mount CD-ROM ISO and it should be no problem to use it when using it as a CD-ROM drive.