Hi there! I have got a PC10 here. How do you use the CF card on PC30 III?
Via an XTIDE card or by using an CF adapter on internal XT-IDE port? Or by using an IDE port on an ISA card?

I should have mentioned that it is connected via an IDE CF adapter to the IDE motherboard connector.

Ah, I see! Thank you. The internal IDE port is an old 8-Bit version of IDE, I think.

https://en.wikipedia.org/wiki/Industry_Standa … and_current_use

It may work with some CF cards, but it's not being guaranteed.
In all honesty, I do lack the required knowledge here. :(
The guys at dosforum.de or vcfed forums or forum64.de may know more about this.

In principle, the HDD Type can be anything that doesn't exceeds the maximum capacity the HDD/CF card has.

That's how I got an 80MB Conner IDE to work in a 286 in the 90s: I've had selected a 40MB type entry in Setup.
It had values within the limits and the Conner drive did logical translation anyway, so it worked.

That being said, an ISA Multi-I/O Card with floppy controller, serial/parallel, game port and IDE was quite common in 286/386/486 era.

So disabling on-board 8-Bit IDE and using a standard IDE port might help.
Using XT-IDE Universal BIOS on an network card, too.

Edit: For testing purpose, there's also a floppy based version:
XUBDisk - floppy disk XTIDE Universal BIOS booter

Those old BIOSe might shave compatibility issues with anything made past 1996, when ATA-2 came out.

This article gives an nice impression how little changes can break things:
https://www.os2museum.com/wp/how-to-please-wdctrl/

An alternative would be to try an XT-IDE card.
It's 8-Bit ISA sadly, but on positive side has XT-IDE Universal BIOS included.

If the BIOS has the option to enter values manually, run a utility like IDEINFO and enter the reported valued for the custom type.
If not you can install some Dynamic Drive Overlay (DDO) software like EZ-Drive and select any type.
In any case make sure you do an fdisk /mbr before partitioning.

konc wrote on 2025-04-05, 13:43:

If the BIOS has the option to enter values manually, run a utility like IDEINFO and enter the reported valued for the custom type.
If not you can install some Dynamic Drive Overlay (DDO) software like EZ-Drive and select any type.
In any case make sure you do an fdisk /mbr before partitioning.

+1

The only problem I see here is that this IDE port isn't a real IDE port.
It's meant for XT-Bus HDDs, rather than AT-Bus HDDs (aka IDE or ATA).
That means the IDE port adresses aren’t same and that the protocol is a bit different.

Another problem is that modern CF cards may nolonger support 8-Bit mode.
They did when we still had 8 MB CF cards, rather than 8 GB CF cards.

Then there's the DDO software. The PC 30 III has an 286 CPU.
It may work on a 286 or not. Some DDOs may use 386 instructions, not sure.

Edit: On a second thought, it might be possible to use an emulator to test things.
PCem/86Box can emulate Commodore PCs, along with their BIOS.
Not sure about emulation of XT-IDE, though.
The Amiga emulator WinUAE features Commodore PC emulation indirectly.
The Commodore A2286/A2386 use same Commodore PC BIOS, I think.
Pictures: Re: Emulation on MS Windows 3.1x ?

Jo22 wrote on 2025-04-05, 18:12:

The only problem I see here is that this IDE port isn't a real IDE port.
It's meant for XT-Bus HDDs, rather than AT-Bus HDDs (aka IDE or ATA).

I believe it is, the PC 30-III was shipped with WD 93028-AD which is a 20MB IDE HDD. And it has the same motherboard (minus the VGA) as the PC40-III which was sold with a 40MB IDE HDD.

Also PCs with the 8-bit XT IDE don't usually offer the list of AT HDD types to choose from in the BIOS, or support a second HDD.

Please do correct me if I'm wrong though, I haven't consulted any official manual/documentation before writing this.

konc wrote on 2025-04-05, 19:28:

Please do correct me if I'm wrong though, I haven't consulted any official manual/documentation before writing this.

In the name of the Moon, I'll correct you! 🌕🧚🪄✨ ^^

(Just kidding!)

konc wrote on 2025-04-05, 19:28:

Jo22 wrote on 2025-04-05, 18:12:

The only problem I see here is that this IDE port isn't a real IDE port.
It's meant for XT-Bus HDDs, rather than AT-Bus HDDs (aka IDE or ATA).

I believe it is, the PC 30-III was shipped with WD 93028-AD which is a 20MB IDE HDD. And it has the same motherboard (minus the VGA) as the PC40-III which was sold with a 40MB IDE HDD.

Hi, the WD93028 also exists as WD93028-A (AT-Bus) and WD93028-X (XT-Bus)..
But again, this was before my time. My 286 had no integrated HDD controller.
My dad and me installed an primitive IDE host adapter (ISA card with some glue logic; address decoder etc).
And the PC10 I have was using SCSI, before I've added an XT-IDE Deluxe/MicroRAM card.

konc wrote on 2025-04-05, 19:28:

Also PCs with the 8-bit XT IDE don't usually offer the list of AT HDD types to choose from in the BIOS, or support a second HDD.

I don’t know much about 8-Bit IDE ports on old computers, sadly. 😥
Though I think that the AT BIOS also works with ST-506/ST-412 (MFM/RLL) and ESDI hard drives, which already had HDD types.
Like our ordinary IDE/AT-Bus, they use WD1003 compatible controller language.
The basics of it, at least. IDE added identify stuff (drive name) that's not supported by the original PC/AT Fixed-Disk Controller.

Edit: What made me doubt was this Wikipedia text, by the way.
Because it mentioned Commodore computers.

XT-IDE Before the 16-bit ATA/IDE interface, there was an 8-bit XT-IDE (also known as XTA) interface for hard disks. It was not n […]
Show full quote

XT-IDE
Before the 16-bit ATA/IDE interface, there was an 8-bit XT-IDE (also known as XTA) interface for hard disks.
It was not nearly as popular as ATA has become, and XT-IDE hardware is now fairly hard to find.
Some XT-IDE adapters were available as 8-bit ISA cards,
and XTA sockets were also present on the motherboards of Amstrad's later XT clones as well as a short-lived line of Philips units.
The XTA pinout was very similar to ATA, but only eight data lines and two address lines were used,
and the physical device registers had completely different meanings.
A few hard drives (such as the Seagate ST351A/X) could support either type of interface, selected with a jumper.

Many later AT (and AT successor) motherboards had no integrated hard drive interface
but relied on a separate hard drive interface plugged into an ISA/EISA/VLB slot.
There were even a few 80486-based units shipped with MFM/RLL interfaces
and drives instead of the increasingly common AT-IDE.

Commodore built the XT-IDE-based peripheral hard drive and memory expansion unit A590
for their Amiga 500 and 500+ computers that also supported a SCSI drive.
Later models – the A600, A1200, and the Amiga 4000 series – use AT-IDE drives.

Source: https://en.wikipedia.org/wiki/Industry_Standa … and_current_use

Edit: Personally, I think it shouldn't hurt to leave things as is and see if XUBDisk does detect something.
It expects the IDE port a the default address.

Also useful is this site: https://dosdays.co.uk/topics/xt_ide_vs_ide.php
The PC20-III does definitely use XT-IDE, at least. Not sure about PC30-III.

Edit: In this thread, someone also had assumed that the PC30-III uses XT-IDE, while others don't think so.
https://www.dosforum.de/viewtopic.php?p=86723#p86723

Personally, I'm simply unsure.
I don’t have one at hand and the Commodore manuals are of no big help. 🤷‍♂️

Yes, it would make sense that an 286 PC also has normal IDE, but I don't think of Commodore being rational per se.
In my eyes, Commodore was a proud producer of cheap low-end hardware which didn't care about performance too much.

Thus, it could also have been the case that Commodore recycled a prior, existing PC/XT motherboard design to make a Frankenstein PC.

Some Tandy 1000s were no different, after all:
XTs with 286 procecsors and no extended memory..