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Category: Retro computing

ISA over USB

ISA over USB

Plugging in old ISA cards is something that hasn’t really been possible since 80486 days. This makes plugging in cool things like Sound Blaster, Adlib, Monster3D and other ISA cards pretty much impossible for modern computers. It also means things like attaching 5.25″ floppy drives and old MFM/RLL drives are also off the table. Well, maybe. 🙂

There have been a few efforts to enabling plugging in ISA boards to modern pc.

  • dISAppointment that I wrote about before is a USB plugin that exposes an ISA interface.
ISA buses on a modern PC?

ISA buses on a modern PC?

Welcome to dISAppointment! Well, it has been disappointment for anyone wanting to use old retro sound cards or attach 5.25″ floppy drives or MFM/RLL hard drives in modern computers. They all relied on ISA controllers, which have not been supported for over a decade now. But is that about to change?

I recently read about this really clever hacker’s adapter.  TheRasteri found he could still access the ISA bus lurking latently in modern computers through the Low Pin Count (LPC) bus which is exposed on the TPM port in many modern motherboards. He created a hardware interface board that connects to the TPM port, exposes an actual ISA slot.

He plugged in a Sound Blaster card via the adapter – and voila! It worked.

More details on his YouTube site, or you can follow the active development thread on Vogons. No word yet if he’s producing any for purchase; but he does want to open source the work and wants to see if he can partner with PCBWay to develop them.

I for one would absolutely buy a few of them.

Update:

Fintek makes the F85526 PCI Express to ISA Bridge IC.

  • PCI Express base spec 1.1 compliant
  • Fully ISA bridge support except bus master

It seems promising, but it is unclear if anyone has built a functioning device around the chip. Vogons even discussed it on their thread that also mentioned the dISAppointement ISA device.

New Old Sound cards

New Old Sound cards

Retro gaming has a solid community – even in the PC world. Prices of old hardware keeps going up as supply of working components goes down as time goes on. But would you be surprised to hear that people are out there making new components for these old machines? I already mentioned the recreated Covox Speech Thing, but there are even re-creations of Adlib, SoundBlaster, and other early sound cards. Enter the Orpheus ISA 16 sound card that can emulate just about any 90’s era sound card perfectly.

Dreamblaster available for purchase here: https://www.serdashop.com/RetroSoundcards

Update: There’s other makers of clone cards too:

IBM PC Convertible

IBM PC Convertible

My very first computer was a TSR-80. I learned to first code out of necessity – you had to type in all the programs you wanted to play. My dad then purchased one of these wonderful beauties: The IBM PC 5140 Convertible.

Art Institute of Chicago

The computer was a miniaturized IBM XT 8088 system with only 2 floppy drives and no hard drive. Still, it was a huge step up with the ability to save and load programs from floppy disks.

I love that people try to preserve the history of these wonderful old machines – and you can find everything about the system including original boot disks, specs, and configurations. There also appear to be copies of the original boot disk and ROM set that work on MAME.

Parallel Sound from the Past

Parallel Sound from the Past

Back in the 90’s, computer audio devices were really limited. If you were relatively rich, you could afford a $150 Sound Blaster, or maybe a $75 Adlib. If not, you were limited to the very humble PC speaker. It turns out, however, there was one other option that didn’t get a lot of visibility.

The Covox Speech Thing (and a similar device called the Disney Sound Source) was an external audio device attached to the printer port and could output digitally generated sound. The device was a criminally simple 8-bit DAC created with a resistor ladder, an analogue output plug, and ran off simple digital signals from the printer port of the PC. How simple was it? So simple you can easily make it yourself.

Necroware does a great job covering the device, how to make your own, and gives you a full tour of the device as well as 90’s software you can use with it. Most notably, Tracker software which gave me tons of fond memories.

Update 02/2024:

Serdashop has the Covox compatible CVX4 Vogons Tuning Edition for €20. Now on it’s 4th and final version – CVX4 uses very high precision 0.1% all same value resistors, and a reverse engineered schematic (based on a real original covox). Other DIY clones use 1% or 5% resistors. Probably one of the best versions out there.

Links:

8″ Floppy drive

8″ Floppy drive

8″ floppy drives are the earliest form of floppy drives connected to early minicomputers. By the time of personal computers, 8″ floppy drives had been replaced with 5.25″ floppy drives. But those 5.25″ (and later drives) were still often based on the Shugard interface.
Adrian’s Digital Basement shows how he hooked up an 8″ floppy drive from a TSR-80 Model II to a 386SX computer – and gets it to boot! This is almost certainly something I want to try some day.

Link:

Reading 3.5″, 5.25″, and 8″ floppy disks with Raspberry Pi

Reading 3.5″, 5.25″, and 8″ floppy disks with Raspberry Pi

It looks like people have been using Raspberry Pi’s to connect and read floppy disks. Below are some of the links. Note that it appears they are only reading data, not writing. See my other posts for both reading and writing to 5.25″ and other floppy drive interfaces.

Links:

GreaseWeazle

GreaseWeazle

Have you wanted to read and write data off your old 5.25″ floppy disks with a modern computer? Or how about reading/writing floppies for Apple II, Amiga, ST, or a host of other systems? Or maybe even hooking up a 8″ floppy? It is possible!

There are solutions out there, but they can easily run $100 or more. I, however, picked up the GreaseWeazle and read some of my old 5.25″ disks. Best yet, it only cost $31 Canadian and is one of the more capable solutions. You can supposedly even use your old DOS floppy drive to read/write images for other platforms.
If you’re interested in seeing it at work on some unusual formats, this fellow gives a walkthrough of using Greaseweazle to read 3″ Amstrad disks. Pretty darn cool.

Items you’ll need:

  • GreaseWeazle by Decromancer – the plug-in USB board that makes it all possible. Plug in 3.5″, 5.25″ and 8″ drives and read/write the flux data for hordes of different formats.
  • Floppy drive – any 5.25″, 3.5″ or 8″ floppy that uses the Shugart interface. This is almost all old PC drives. Even better, GreaseWeazle can use these older DOS drives to read and write Apple, Amiga, ST, and a host of other formats.
  • Floppy disk cable – CablesOnline (ebay store) has a universal floppy cable Item # FF-002 for $9.99
  • Power supply with Molex connectors for the floppy drive. Either using a PC power supply with a Molex connector, or a stand-alone power supply with Molex connector
  • USB A to B cable (commonly known as a “USB printer cable”) to connect the GreaseWeazle to your PC

Setup:

Your floppy drive won’t show up in a command prompt like they did back in the old DOS days or like modern USB plug-in 3.5″ drives. Instead, you have to load and write whole images to the drive in one go. This means you need to work with floppy disk images.

  1. Set up your physical floppy drive to be used with GreaseWeazle.
    1. Attach the power cable to a power supply
    2. Attach the data cable to the floppy drive and the GreaseWeazle
  2. Follow the instructions on GreaseWeazle setup and software setup guide.
  3. Plug in the GreaseWeazle to your computer’s USB port
  4. Install and run GreaseWeazle GUI to format a disk, read a disk image, write a disk image, etc. Again, this only works on whole disk images. You can’t browse at a command prompt or read/write individual files/directories.

Optional but helpful tools:

  1. WinImage is a great tool for creating and converting disk image formats.
  2. Use the HxCFloppyEmulator to examine and covert the raw disk images to anything you need.

Learn more:

Tech Tangents talks about how preservationists use tools like GreaseWeasle to back up disks.

Resource Links:

Running Windows 1.01 and old versions of DOS

Running Windows 1.01 and old versions of DOS

I learned to program back on an old TRS-80 Model III computer as a kid. Long before Windows and even DOS, most home computers required you type in programs or load them from cassette tapes. If you were really rich, you might afford a floppy drive, but that was an expensive luxury I never had. My next computer was an IBM XT, and it ran the advanced and stalwart DOS 3.30 – which was dramatically better.

Running those old operating systems today requires you either buy one of those old systems and keep it running, or you have to emulate them. You can easily emulate DOS 3.3 and Windows 3.0 and higher on VMWare or Virtualbox, but going earlier than doesn’t seem to be supported anymore.

Enter 86Box – an emulator that lets you emulate REALLY old machines. In fact, I was able to get Dos 3.2 running Windows 1.0.

Here’s what you’ll need:

Part 1 – 86Box Setup

  1. Download 86Box and install it (source is on github).
  2. Download the latest romset and put it in the directory for 86Box called roms\
  3. Download DOS 3.2 image disks here.
  4. Download Windows 1.01 image disks here.
  5. [For later fun: download any of the other amazing images on the parent page]
  6. Start 86Box and set up 86Box by selecting Tools->Settings from the top menu, and set the system up with the following settings.

Part 2: DOS 3.2 and Windows 1.01 install

  1. Start up the 86Box.
  2. Set Media->Floppy 1 to disk01.img, then issue a ‘CTRL-ALT-DEL’ to reset it. The system should start up and boot to the dos 3.20 floppy drive
  1. Run ‘fdisk’ and it should detect your hard drive. You’ll need to create a partition to set up the hard drive.
  1. Reboot and boot from the DOS 3.20 disk again.
  2. Format the hard drive by using ‘format c: /s’
  3. Set Media->Floppy 1 to ‘DISK1-SETUP.IMG’ from the Windows 1.01 (5.25)
  4. [optional] type ‘set prompt=$p$g’ if you want to see your full path in the command prompt
  5. Run ‘setup’ from a: and follow the instructions to install Windows 1.01 on C:. Change the disks when prompted by selecting Media->Floppy 1 and setting it to each of the floppy disks for the Windows setup until it’s completed.
  6. type ‘C:’ to switch to the hard drive
  7. ‘cd \windows’
  8. ‘win’ to start windows
  9. Voila!
Attaching 5.25″ floppies via USB

Attaching 5.25″ floppies via USB

Floppy disks are a relic of the past these days. You can still see the odd 3.5″ floppy – and there are even still companies making 3.5″ USB drives you can plug into your system today. But 5.25″ floppy drives (360k and 1.2 meg variety) are much more scarce. So scarce, in fact, that you’re likely not to find any outside of an old vintage computer. Most modern PC’s since the Pentium don’t even have connectors, interfaces that support them, and I know of no vendors that make USB 5.25″ drives.

So what is one to do if they have old 5.25″ floppies they need to read? Turns out others have had the same problem – so you’re not alone.

Here’s some options:

  1. Find a service that will convert them – Usually for a fee around $5-$25 per disk.
  2. Buy an old vintage Intel pre-Core based computer from eBay that has a working 5.25″ drive.
    This means a 486 or lower computer. Almost all plug-in floppy controllers require a PC who’s motherboard has an ISA interface (not PCI). You must also be careful because older 8-bit ISA floppy controllers (from the XT/AT era) often will NOT work in faster 386/486/Pentium ISA interfaces (even though they are supposed too).
  3. Use a flux-style reader. These allow you to attach a 5.25″ drive to a controller board which then connects to your USB port. The big limitation is that you cannot interact with the disks via DOS or command line options. Instead, you need to read/write whole disk images or operate at the sector level. These readers do this by reading flux data. While this is more complicated, it is the method that archivists are using to backup disks. Reading flux data gives you the ability to read/write disks from almost any platform and in any format – even copy protected disks.
    1. GreaseWeasle V4 [NEW 2022]https://decromancer.ooo/greaseweazle/
      Interfaces with 8″, 5 1/4″, and 3 1/2″ drives. Amazingly, it only costs $31 CAD and seems to get as good reviews as the Kryoflux. Definitely one of the cheapest options on this list. Since it extracts the raw flux transitions from the drive, any diskette format can be captured and analyzed – PC, Amiga, Amstrad, PDP-11, many older electronic musical instruments, and industrial equipment. The Greaseweazle also supports writing to floppy disks. The design is fully open and comes with no license encumberment.
      [UPDATE 10-2022] I just bought one of these and could not be happier. It’s pretty sweet!
    2. Kryoflux https://www.kryoflux.com/
      The Holy Grail of floppy readers, but not cheap at 105€. It is able to read all formats, save as a raw stream, or export to common sector formats like the Acorn Electron, Apple, Amstrad CPC, Archimedes, Atari 8-bit, Atari ST, BBC, Commodore 64, Commodore Amiga, MSX, IBM PC, PC-8801, Sam Coupe, Spectrum, E-MU Emulator & Emulator II, DEC RX01 & RX02 and many others.
    3. Device Side Data’s FC5025http://www.deviceside.com/fc5025.html
      USB 5.25″ floppy controller plugs into any computer’s USB port and enables you to attach a 5.25″ floppy drive. Even if your computer has no built-in floppy controller, the FC5025 lets you read those old disks. It also understands formats used by Apple, Atari, Commodore, TI, and others.
    4. Supercard Prohttps://www.cbmstuff.com/
      I don’t know very much about this one, but here’s a review and this page which contains a lot of useful information.
    5. DREM https://www.drem.info/
      DREM is a MFM/RLL hard drive emulator that can read raw dumps of a hard drive. It also allows you to read floppies. More here.
  4. ISA on modern PC’s

Cables/Adapters for connecting 3.5/5.25/8″ floppy drives to your PC:

  • CablesOnline http://www.cablesonline.com/ also their (ebay store)
    CablesOnline has a good selection of universal floppy cables for a very reasonable price.
  • IEC.net also has a selection of floppy cables, and can custom-make floppy cables for you.
    • They also have MFM and RLL hard drive cables (and can make them to order)
  • Dbit http://www.dbit.com/fdadap.html
    The DBit FDADAP board is a small adapter which adapts 8″ floppy disk drives (Shugart SA800 style bus) to work with the PC 3.5″/5.25″ floppy disk cable pinout. It has 34- and 50-pin connectors which can be connected to the PC floppy controller and the 8″ disk drive using simple straight-through ribbon cables (not included), and a 3.5″ style power connector for the on-board microcontroller
  • TexElec – https://texelec.com/product/8-inch-floppy-adapter/
    TexElec makes tons of retro computing dream boards (clone Adlib, IDE, floppy, and other controllers) as well as this 34 to 50 pin 8″ floppy drive adapter board that allows you to plug in 8″ floppy disk drives with a standard PC 3.5″/5.25″ floppy disk cable.

Dead/Discontinued controllers

  • Catweasel http://www.nishtek.com/cw.html
    Discontinued PCI board for connecting to floppies. Like other solutions, it doesn’t make drives show up as a drive letter – but rather lets you read raw formats for all sorts of platforms.

Other resources/discussions: