Restoring an Australian Classic


#22

The scrap XT chassis would be, and I’ve been considering that option once I have some cash set aside. I wouldn’t mind a powerful machine for running games and 3D applications.


#23

Some of the last few needed components started to come together over the last couple of months. A member of the Overclockers Australia forums donated a CPS Sound Blaster 2 ISA-8 sound card to this machine, a member of the Vintage Computer Federation sourced a replacement Seagate ST-412 MFM HDD in excellent condition, and a local collector here in Adelaide had a network card and twisted pair transceiver compatible with the 8088 XT.

The machine took some convincing to accept the wide array of cards and accessories being thrown at it. The available IRQs and I/O addresses are almost maxed out, but somehow there were enough free to support all of them at once. There was a minor conflict between the VGA video adapter and the Network Interface as both attempted to communicate on the same IRQ (2/9), but this was resolved by disabling a function of the VGA card otherwise unused on the XT anyway.

Loading the necessary software and drivers onto the machine was a battle and a half. With a 3.5" Floppy Drive connected to the primary controller temporarily, I was able to format and use 720k disks for the initial transfer with a Windows 98 PC in between as a bridge. This allowed me to install MS-DOS 5, the Sound Blaster Utilities, a Network Packet Driver and the mTCP communication suite onto the internal 10MB drive.

From there the rest was simple. Connect the Ethernet Transceiver and network cable to an AirPort Express in wireless bridge mode, run the DHCP command to retrieve an IP address, start the XT’s FTP server and transfer the remaining data from the MacBook Air wirelessly. Success!

This IBM XT now communicates online, connecting to IRC channels and Bulletin Board Services (BBS) rather well. Transferring data and classic games around is easy, with the XT FTP server running and an FTP client on a newer machine. With a genuine hardware Yamaha OPL2 FM Synthesiser installed, it produces excellent chiptune music. I’ll find some additional instruments and voices for it soon and make some music. It even serves static HTML pages - a web server with a 4.77MHz CPU and 640KB RAM.

The machine is almost finished. It needs some minor tweaks, and I’ll continue looking for some rare cards and accessories to match it, but I’m pleased with how it’s all come together. It’s an interesting machine that’s surprisingly easy to immerse yourself and get lost in. The fact it communicates so effortlessly with machines 31 years its junior is certainly a plus, and makes it much more usable for specific tasks than some may think it would be.

I’m not convinced I’d be able to perform a restoration of this caliber again. The amount of repair work needed, along with sourcing rare and discontinued parts, turned this into a lengthy and at times expensive process. I don’t regret it for a minute, because it’s a beautiful machine and one I’m extremely proud of.

Both the Commodore Amiga 500 and a Nintendo 64 restoration (and collection) I’ve been working on are next. I’ll be looking to document these as well, if my limited free time allows for it.


#24

I loved my XT and used to run BBSes off them as a kid. The memories…


#25

Reading this thread, I’m both heartened and amazed at how much you know about this machine. My mother is a historian, and the inherited historian in me is so pleased to see that we haven’t lost all of the knowledge that got us to this point. I fondly remember my early days of computing, and have a few old Macs here that I aim to get up and running ‘one day’… whenever that is! :grimacing: But it’s great to see that some of that history is preserved. Well done mate!


#26

Wow. Really great work. What a blast from the past. Thanks for sharing.


#27

Amiga 500 was the best. Those are making a huge comeback now.


#28

Wasn’t the whole brand going to come back at one stage?


#29

My Dad gave me his when I was 4 to ‘play’ with. I believe the power adaptor had died so he chucked that and gave me the machine to play with. I unforuently took it apart and put it back together and ripped off part of the bottom (I think it was an expansion slot on the base)- I still have it and it looks ok but obviously missing whatever was in the expansion slot. I’d doubt it works after I dissembled it :open_mouth:

I’d love to restore it though. I’d need a PSU to test it though :stuck_out_tongue:

After the Amiga 500, dad got the LC 475, our first Mac.


#30

My Amiga 500 got sold as its how I funded my first IBM clone… an AT 386 based system… anyways…


#31

Better sold then destroyed by a child haha :stuck_out_tongue:


#32

The Commodore Amiga 500 needs some serious work, including refinishing some card edge connectors and having the EMI shields professionally replated.

But I’ve started working on another machine since then.

Anyone familiar with this one? These machines have some interesting history behind them.

I’ll give everyone a hint - it was manufactured in Adelaide.


#33

I’ve never seen that one before. Although when I had my C64 and later Amiga 500. I just lived and breathed those things… didn’t look at anything else,.


#34

I don’t know anything about the PC but I had one of those Genius 3 button mice on my first PC (a 386, in 1991)


#35

I’m not surprised this machine remains unknown to most, as it wasn’t as common a sight as an IBM, a Commodore or an Apple. It’s a Micro Byte PC230, designed and manufactured by Micro Byte Systems in Adelaide, South Australia. This machine was manufactured somewhere around 1989-1990, and it contains some interesting characteristics that set it aside from typical PC clones of the era.

It uses an NEC V30 processor running at 4, 7 or 10MHz, selectable in the BIOS configuration utility. The machine is a combination of standard and custom engineered parts, using a custom designed motherboard, paired with 2 internal Shugart standard 720k disk drives, a MiniScribe SCSI drive on a Western Digital controller and a power supply that looks and functions identical to many Apple IIe clones, complete with the same connector and pinout. The computer even has an external disk drive connector for an optional 5.25" drive.

The machine is housed within this slim, low profile case, and is easily transported with the matching Micro Byte carry bag.

An interesting quirk of the machine is that it uses a SoftBIOS. The ROM on the motherboard contains some basic bootstrapping functionality to start the machine and access the disk drives, then loads an extended BIOS from disk into memory. The BIOS is configured from a DOS command line utility. This made BIOS upgrades easier, since an updated disk could be distributed instead of replacing the onboard ROM chips, but it does mean that if the original system disks are lost, the computer is rendered essentially unusable. Thankfully these disks have been archived and aren’t overly difficult to find.

Mine is a near complete system, complete with the machine, monitor, keyboard, mouse, external disk drive, manuals, disks and carry bag. It was retired and stored away some time in the early 1990s, and remained in storage until I was offered the machine last week. It’s in excellent condition as a result.

The reason the computer is near complete is because it’s missing the ISA expansion slot riser card. The machine works without it, but no additional expansion cards - such as sound or networking - can be installed without it. It’s a shame, and finding a replacement card for a rare machine will be difficult, but I’ll continue to look around in the hopes of eventually finding one.

Eventually I’ll make new disks, install both MS-DOS and Windows 3.0, and see what it can do.


#36

Your 230 is definitely missing the lo-rise vertical ISA card adaptor. Good luck finding one of those outside of a 230 itself!

The 230 had some nifty features, including being able to use memory between 640k and 1 MB for screen display use without the need for EMM/XMM drivers.

The 230 was superceded by the MicroByte PC230-SX, an 80386SX-16 Mhz system. 230’s could be easily upgraded to 230SX’s with a straight motherboard swap. I used to do this at the University of Adelaide in the early 90’s and could do it in less than 5 minutes.

The Soft BIOS was a selling point, the advertising tagline being “Obsolescence is Obsolete”.

You’ll get real-mode Windows 3.0 working OK on it. Microsoft demo’d WIndows 3.0 to us in mid-1989 on just such a system.

The MicroByte systems were well designed and engineered - the first “pizza box” style PC systems I worked on. They were truly “Made in Adelaide”, and I believe that DSTO assisted with the multi-layer circuit board fabrication.

After the 230 and 230SX they tried their hand as something called the HC-120. This was a computer embedded in a keyboard that had floppy disk and a single ISA port for network card use only. It was designed purely for education but I don’t think I saw this outside of the old computer shows that used to run at Morphettville racecourse.

About a year after the 386SX variant was released, MicroByte went into receivership and disappeared from the Australian computing landscape as education sales dried up in favour of Acer, Dell and another Adelaide company MicroBits, who themselves folded not long after.


#37

The machine now has an ISA riser, found one locally last week from another collector that had an incomplete spares machine. Mine is also missing the card standoffs on the drive cage, meaning the card is loose inside the machine except for the connection to the motherboard, so I’ll either attempt to find a suitable drive cage or have standoffs fitted to the existing bracket somehow.

I’ve installed Windows 3.0 and MS-DOS 3.3 on the internal hard disk, which did need some persuasion to start working again - seems to be common for the stepper to stick on these old MiniScribe 8425s. I think the grease needs to be moved around a bit after sitting for an extended period of time.

A PC230-SX would have been preferable, since I could have installed a later Windows version on it, but no matter. This one works alright. I can’t imagine they were common anyway, being in production for such a short amount of time.

Finally, I saw a Micro Byte HC-120 up close last week, from the same collector I obtained the spare riser from. Talk about an interesting machine, almost like a Commodore Amiga with PC compatible internals. There are few photos and documents out there about this machine, although hopefully that will change soon if we can start better documenting some of these units.


#38

What a fabulous thread! It makes me feel very nostalgic as my first PC was the the IBM 5160 (US built), but with a MGA card and the IBM green monochrome screen Keep up the good work with the restorations!