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Ask Slashdot: Supporting "Antique" Software?

timothy posted about a year ago | from the why-in-my-day dept.

Hardware 212

First time accepted submitter wolfguru writes "As the IT Manager for a large printing firm, I often have to provide hardware to support older software which is used to configure and maintain existing systems, some of which are nearly 20 years old. Much of the software uses RS-232 serial communications to connect to the PLC devices and is often 16 bit versions. Newer systems from the PLC manufacturers supports some of the equipment, but many of the older PLC consoles are essentially unreachable without the serial communications. For any of you faced with similar challenges in keeping a manufacturing environment maintenance department working; what do you use to support them and where do you find equipment that will run the older systems that are sometimes the only means of supporting these types of devices?"

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Please (0)

Hsien-Ko (1090623) | about a year ago | (#43883875)

The DOSBox forums are fled by incompetent IT pros that demand support for their old versions of dBase. It's rather depressing.

Re:Please (1)

NJRoadfan (1254248) | about a year ago | (#43884031)

There is demand for a DOSBox like product that supports legacy productivity apps. I haven't had any problems running things like Wordperfect 5.1. If anything they are easier to get running compared to picky DOS games and demos!

Re:Please (1)

ericloewe (2129490) | about a year ago | (#43884267)

What doesn't DOSBox have that games don't need but business stuff does? Usually games are those things that require very good compatibility, and DOSBox is perfect in my experience...

Re:Please (1)

chipschap (1444407) | about a year ago | (#43884317)

DOSBox is really, really good but does not include printing support. That can be a problem with productivity apps; you have to print to file then print the file (not even possible with every app).

Re:Please (1)

NJRoadfan (1254248) | about a year ago | (#43884383)

There is a SVN build that includes Epson LQ (ESC/P) color printing support. It isn't perfect, but it works. With some changes, DOSBox could easily intercept data written to LPT1: and send the output to a file.

Re:Please (5, Interesting)

Jappus (1177563) | about a year ago | (#43884757)

Actually, newer SVN + patches builds for DosBox go much further than that: []

The best one, if you ask me, is the SVN Daum build (alas, their website is down at the moment). To quote its set of difference to Vanilla DosBox:

Description: The Windows build incorporates Direct3D with pixelshaders, OpenglHQ, Innovation, Glide, zip/7z mount, Beep, NE2000 Ethernet, Graphis user interface (menu), Save/Load states, Vertical sync, CPU flags optimization, Various DOS commands (PROMPT, VOL, LABEL, MOUSE, etc) and CONFIG.SYS commands (DEVICE, BUFFERS, FILES, etc), Continuous turbo key, Core-switch key, Show details (from menu bar), Nice DOSBox icon, Font patch (cp437), MAKEIMG command, INTRO, Ctrl-break patch, DBCS support patch, Automatic mount, Printer output, MT-32 emulation (MUNT), MP3CUE, Overscan border, Stereo-swap, SDL_Resize, MemSize128, Internal 3dfx voodoo chip emulation, etc.

I emphasized the important bit. What these two little words mean is the this DosBox build can not only emulate a DOS printer to dump stuff into various output formats (PNG, PDF, etc.), but it can also pass along the output to a Windows printer driver (which allows you to print to any USB printer) as well as use a real parallel port on your computer to let the DOS talk directly to the printer.

I know at least one company that is using this DosBox build to support printing out of a 20+ year old billing software.

Re:Please (1)

lister king of smeg (2481612) | about a year ago | (#43884483)

why don't they have it print to postscript. many modern printers take postscript input so it would not be hard to have it pipe the input to the printer.

Re:Please (3, Funny)

gatkinso (15975) | about a year ago | (#43884625)

That is an awesome idea. Let us know when you commit that!

Re: Please (-1)

Anonymous Coward | about a year ago | (#43884665)

Maybe you should. He giving advice, not doing your job.

Re:Please (2)

ericloewe (2129490) | about a year ago | (#43884769)

You're forgetting that in DOS, every application needs its own drivers for anything beyond text mode output (MDA?) and keyboard input, so there's not a single printer interface to emulate - ideally, you emulate the more popular ones.

Re:Please (2)

ericloewe (2129490) | about a year ago | (#43884755)

Ah, of course. Makes perfect sense - the one thing no game needs but every business user needs...

I can't blame them, I would also avoid touching anything printer-related with a 3,048m pole if possible. I guess it comes down to emulating HP LaserJet and whatever else was commonly supported at the time, similar to what's currently done with sound cards...

Re:Please (0)

Anonymous Coward | about a year ago | (#43885035)

The current owners of dBase have a DOSBOX version with dBase printing support.

Re:Please (0)

Anonymous Coward | about a year ago | (#43884605)

DOSBox can't handle Control-Break, which was used an awful lot (for good reasons and bad) in the DOS era.

Re:Please (2)

Jappus (1177563) | about a year ago | (#43884777)

DOSBox can't handle Control-Break, which was used an awful lot (for good reasons and bad) in the DOS era.

See my post from further up in this thread where I've linked to the SVN Daum build of DosBox. Among other things, it contains a very good "Ctrl+Break" patch that adds that particularly little oddity with almost 100% accuracy.

Nowadays, the SVN builds of DosBox can do so much more than the Vanilla DosBox, it's no wonder the maintainers can't decide which of those patches to add to the mainline first.

Re:Please (1)

ultrasawblade (2105922) | about a year ago | (#43885681)


Virtual Machines (4, Informative)

AmiMoJo (196126) | about a year ago | (#43883889)

Fortunately RS232 is still well supported via PCI-e cards and USB, so you can just run the old system in a virtual machine on modern hardware to avoid many of the problems associated with maintaining old gear.

My only other advice is to never underestimate the costs, especially when talking to your boss. He/she will want guarantees that everything runs smoothly all the time, which realistically you can't provide without plenty of redundancy and extensive testing. Be clear that old hardware is hard to maintain and repair, and not trivial to replace.

Re:Virtual Machines (4, Interesting)

NJRoadfan (1254248) | about a year ago | (#43884007)

If USB to serial adapters cause communications problems, most motherboards still have RS-232 headers on them (residing at DOS friendly COM1), just need the bracket. Most of them can run DOS as well as long as they have a BIOS boot option as an alternate to EFI mode.

But dos and older windows 9X apps / os may not (2)

Joe_Dragon (2206452) | about a year ago | (#43884043)

But dos and older windows 9X apps / os may not like USB to RS232 and or pci / pci-e based RS232 ports. Also VM pass though may not work 100%.

You can try running free dos / MS-DOS 7.x or 8 on newer hardware but usb may not work as well.

Re:But dos and older windows 9X apps / os may not (4, Interesting)

hairyfeet (841228) | about a year ago | (#43884857)

I'm surprised nobody has simply named the obvious, which is just pick up an older laptop on ebay. Plenty of old Toughbooks still out there, built like tanks,, with RS232 already on them. Sure it isn't as fancy as setting up VMs and trying to get them to talk to the old gear but sometimes the simplest answer is the best IMHO.

Re:But dos and older windows 9X apps / os may not (0)

Anonymous Coward | about a year ago | (#43885317)

Depends on the scale you are operating at - if you have a few machines that need RS232, this works fine, but when you have a few hundred, maintaining them would be a serious challenge - you'd have to replace whole systems when they break, which is fine from a hardware cost, but may not be from a system setup time perspective.

Re:Virtual Machines (1)

CAIMLAS (41445) | about a year ago | (#43884191)

I've done this. The easy answer to your problem is: virtualization.

Whether you're virtualizing DOS or Win9x, you can use modern USB devices as "real" serial devices on the guests. It works slightly differently with the different platforms (VirtualBox and VMWare are the best at this with VB being the best, in my experience, with XenServer failing and being difficult more often than not). With VirtualBox at least, you can pass a raw port to the guests.

You MAY run into problems with port timing, however. Finding USB serial adapters that have good timing can be a bit difficult, and I don't have good advice on this. However, it still opens up your options and removes the dependency of old hardware.

If you must, you can also buy multi-port serial cards (you can get a cheap 2-port on NewEgg) and pass those directly, or you could use a serial port router/switch if you have enough devices to justify it.

Re:Virtual Machines (1)

rex_s (2562299) | about a year ago | (#43885023)

^^Win. The beverage manufacturer I work for has many of the same ancient PLCs, and we run VMWare Player in Win7 with an XP guest OS and a USB>Serial converter. Gets the job done.

Re:Virtual Machines (1)

LordLimecat (1103839) | about a year ago | (#43885119)

Please, noone who has business needs use Virtualbox.

There are a lot of free / basically free virtualization products out there suitable for business. Unless VBox has substantially improved in the last year or two, it isnt one of them.... unless you like random hangups / VM corruption.

Re: Virtual Machines (0)

Anonymous Coward | about a year ago | (#43884685)

This is along the lines of what I was thinking. Use a terminal server like Moxa nport to relay the data to a dos vm. If the application does not support tcpip you might need to emulate serial.

Consider yourself lucky (0)

Anonymous Coward | about a year ago | (#43883899)

It could be ladder logic and plugboards [] .

Re:Consider yourself lucky (1)

Runaway1956 (1322357) | about a year ago | (#43884297)

Oh, God! That makes me feel sick. We had messes like that when I started working at this company. There are exactly two of them left, and one of them is being dismantled to be carted off to the junk yard. The remaining one is rapidly becoming so expensive to maintain, that no one can justify keeping it around.

We'll still have ladder logic for a long time to come, but no more of those freaking tangled spaghetti wire boards!

Re:Consider yourself lucky (3, Interesting)

inasity_rules (1110095) | about a year ago | (#43884465)

It is a case of the 'right tool for the right job.' In some cases ladder logic is still the best choice. Running interlocking or normal controls like PID and so forth in ladder makes a lot of sense. Sequential function chart can be useful too, but tends to be overused by IT types who get cornered into control and have no clue what they're doing, as does script. Basically, what I'm saying is if we ever throw out ladder, it means we're being pretty thick. Ladder has a place and makes a lot of sense from the process POV, throw too much of it out and you're being stupid.

Naturally, put the 'hardware' ladder system into a suitable PLC that can do SFC as well as ladder and the scripting language of your choice, but don't throw out the logic. That is often still the most logical solution and IT types who think ladder is obsolete should honestly be shot at dawn for the bastards who create un-maintainable messes of spaghetti code that they are. Siemens programmers are the worst culprits here.

Re:Consider yourself lucky (1)

Runaway1956 (1322357) | about a year ago | (#43884585)

Maybe I phrased that poorly - my complaint isn't the logic, but the spaghetti wire boards. Yes, we'll have ladder programs for a long time to come, because it works wonderfully in the type of application that it was designed for. But, it's SO MUCH simpler to work with in an ActionLogic or comparable PLC!!!

Re:Consider yourself lucky (1)

inasity_rules (1110095) | about a year ago | (#43884689)

I would really hate to have to deal with those boards, or even the massive relay logic banks that they used to use. You do have my sympathy....

I have worked with a lot of PLCs, but never action logic. Always curious, how do they compare to the Allen Bradleys and Omrons of the world? I am not tied to any particular setup, except I do have an abiding hate for the bloated mess that is Siemens.

Serial to Ethernet converters (0)

Anonymous Coward | about a year ago | (#43883905)

RS 232 to ethernet adapters (4, Informative)

Anonymous Coward | about a year ago | (#43883925)

They are a god send. For software I use RSlinx Gateway which is for Allen-Bradley PLC's, but has many different driver solutions. Also it will allow you to bridge network connections if your running DH 485/RS 232/DF1/ DH/DH+/Ethernet. Gateway is expensive though there might be a more cost effective solution.

Re:RS 232 to ethernet adapters (0)

Anonymous Coward | about a year ago | (#43884079)

and an isolated network for them I hope. not much security on devices expecting serial port communication.

Re:RS 232 to ethernet adapters (2)

DarkOx (621550) | about a year ago | (#43884105)

Don't know about the particular device you mention but just want to remind everyone to "put some thought into things" before just slapping ip->ethernet->rs232 gateways around all over the place. Many of those old RS232 interface had no authentication or access control, the ones that did usually it was a weak password or pin and no rotation or change period enforced. Lots of the remote ip -> serial port solutions I have seen run clear text too, so even if there is a password on the controller it will be easily sniffed if used often. Make sure you have some sorta of access control on the gateway device and make sure it offers some kinda of encrypted channel or that you know exactly what and who has physical access to the networks between the gateway and the client.

Re:RS 232 to ethernet adapters (2)

wiggles (30088) | about a year ago | (#43884871)

Anyone who merges their production industrial network with their common business network deserves everything they get.

There should be an air gap between industrial control networks and business networks, and the industrial networks should never be able to touch the internet.

Re:RS 232 to ethernet adapters (2)

D1G1T (1136467) | about a year ago | (#43885073)

Yep. IT network administration and industrial networks are very very different, and require totally different mind-sets. I've been in plants where the people from the company's IT department aren't allowed on the factory floor. Deterministic behaviour and safety systems just aren't things your business IT guys ever think of. Conversely, network security is not something automation technologists have needed to deal with until recently, thus all the problems lately.

Re:RS 232 to ethernet adapters (0)

Anonymous Coward | about a year ago | (#43885121)


Kind sir, are you aware that there are hydroelectric dams, car washes, and skating rinks (with a defrost option) connected directly to the Internet? No auth needed!

aka Terminal Server (2)

tengu1sd (797240) | about a year ago | (#43884271)

When you buy a rack mounted unit that does this, it's sometimes called a terminal server. You can provide network to serial access, enable unique passwords on each device and create access lists. When I managed customer equipment, I used to require a DECserver and modem/phone line for last ditch access. In this case, I had firewall, switch, router and console access. Much of this kit is can be found used or see Vnetek [] . I understand Cisco also makes comparable product. You can pair this with virtual comm port driver, letting you drive these units from a central location.

Answer number 2, you need to put a business risk into supporting antique systems. Cost of replacement, downtime to find part vs lost business. Consider stocking in house pre staged replacement systems.

Re: aka Terminal Server (0)

Anonymous Coward | about a year ago | (#43884705)

I fucking hate dec and their mmj over rj45 bullshit. There are other terminal servers that dont rely on goofy rs232 wiring and offer the stability a dec termserver provides.

Re:RS 232 to ethernet adapters - Security warning (2)

Animats (122034) | about a year ago | (#43884385)

RS232 to Ethernet devices have a big security problem - they can expose your RS-232 device directly to the Internet. Many RS232 to Ethernet devices will talk to anything that tries to talk to them. Some have built-in minimal web servers for configuration, and those make it easy for attackers to find the device.

Industrial automation people try to have isolated Ethernets for these devices. But then something comes along that needs to be on the isolated net and also needs to talk to something in the outside world. Then someone reconfigures the isolated net to connect to the outside world. Everything still works fine, until somebody breaks in.

This used to be more of a theoretical attack, but there are now search systems out there finding and cataloging control devices reachable on the Internet.

Re:RS 232 to ethernet adapters - Security warning (1)

inasity_rules (1110095) | about a year ago | (#43884491)

100% of RS232/RS485 to ethernet adaptors I have worked with have had at minimum IP level filtering. Trivial to defeat, I know, but most sit on networks with no direct connection to the internet. And honestly if you've got a hack on your subnet you have bigger problems than the fact that he can access your unknown (to him) PLC. Like the fact that he can own your SCADA and break things without having to understand ladder logic in the PLC.... Worry about your SCADA first, and your conversion devices second....

Re:RS 232 to ethernet adapters - Security warning (1)

LordLimecat (1103839) | about a year ago | (#43885163)

Trivial to defeat,

Only if its UDP, and only if you dont care about return traffic.

Spoofing an IP is really only useful when you are flooding a target and really dont care about bi-directional communication, or if youre punching a hole in a firewall with the help of an intermediary server.

Re:RS 232 to ethernet adapters (2)

some old guy (674482) | about a year ago | (#43884435)

Excellent call. You beat me to it.

The bridge hardware is worth every penny. By the time somebody grinds out a kludgey emulator zombie for some junk freeware, you're up and running with your system. In a factory environment, you often just don't have time to indulge in experimental development of custom applications.

You can also see if the old RS-232/485 gear is recognizable by a Phoenix Contact or Wago DeviceNet-Serial hub. That's even easier since all modern PLC's support DeviceNet out of the box, and the hubs are fairly inexpensive.

Re:RS 232 to ethernet adapters (2)

gatkinso (15975) | about a year ago | (#43884635)

The serial interface is not the problem, the 16 bit software talking through it is.

USB To Serial (0)

PantherX (23953) | about a year ago | (#43883933)

It seems that pretty much every datacenter needs a bunch of these: []

They work well, though I'm not sure about software, as it was suggested previously, a virtual machine sounds like it should work for what you need.

Re:USB To Serial (1)

fatalwall (873645) | about a year ago | (#43884275)

Those often run into problems. Often when using those I have had to fiddle with settings. Some software has limitations as to which port the device needs to be plugged into. Yes you can reroute but thats part of the fiddling. Getting a stack of old laptops with rs232 ports has always been the most reliable way I have found. Sadly ensuring you have enough to last the life of the device your communicating with can be an issue.

Y2K (0)

Anonymous Coward | about a year ago | (#43883949)

The only issue with your old software will be to make sure it is Y2K compliant, apart from that, it'll keep going forever as long as the surrounding hardware holds out.

Oh, wait....

Re:Y2K (1)

Smallpond (221300) | about a year ago | (#43884623)

Not even. Our data center had an irreplaceable piece oif software that was not Y2K so they just declared that 2000 = 1970. It was finally replaced last year (1982).

Re:Y2K (1)

LordLimecat (1103839) | about a year ago | (#43885173)

You know, when i was new to the industry, I would have thought you were full of crap.

But now I find that sadly plausible.

Have a look at PCs for Industrial Automation. (5, Informative)

stasike (1063564) | about a year ago | (#43883967)

At work we use Industrial PCs for work with PLCs. You can still buy PC with an ISA slot, and most of industrial PCs have good old serial port. Just contact any competent supplied of industrial automation equipment.
One of manufacturers is Advantech. Have a look at their UNO line of "brick" computers. Plenty of industrial RS232 and RS485 ports even in the most basic models. Computers are fanless and built to last. Unfortunatelly, those machines are bloody expensive.

If you look really hard, you can even find new 486 machines. Those are even more expensive than Advantech bricks I wrote about, but there are still people that need those computers, so there are companies able to provide them at a cost.

Re:Have a look at PCs for Industrial Automation. (0)

Anonymous Coward | about a year ago | (#43884147)

let me add look there :

Re:Have a look at PCs for Industrial Automation. (2)

Dadoo (899435) | about a year ago | (#43884365)

You can still buy PC with an ISA slot

You don't need an ISA slot to get serial ports. Just a few months ago, I put together a brand new computer at work that has two RS232 ports on a PCI-express card. You can get one from Newegg for around $50.

Re:Have a look at PCs for Industrial Automation. (1)

inasity_rules (1110095) | about a year ago | (#43884521)

Fanless industrial PCs tend to be more than R500. Also they tend to run old hardware and DDR2 RAM is now really expensive. It is silly, but it is the way things are. And fanless is a must in, for example, an environment which corrodes copper or tin in solder. And yes, I do work in such situations.

Re:Have a look at PCs for Industrial Automation. (2)

number11 (129686) | about a year ago | (#43884567)

You can still buy PC with an ISA slot

You don't need an ISA slot to get serial ports..

No, but there are specialized boards that still have ISA slots. Sometimes it's considerably cheaper to replace the computer and keep the board, rather than vice versa. A new board will probably require new software, perhaps only available from a single vendor, and it may require retraining doctors, I mean users, who hate change. And, to be honest, if the old system did what they wanted, there's no reason to inflict something different upon them.

You need to come up with a migration strategy (1)

prefec2 (875483) | about a year ago | (#43883969)

The strategy should include a short time support strategy for old hardware. You can run 20 year old software on today's PCs either directly or in a virtual machine. However, you might have problems, because they are too fast. This short term support must be supplemented by a migration strategy for the old PLCs. I know that is hard, have worked in a project using PLCs in railway control systems, which have to run for 20 or more years before they are replaced again. Therefore, you need also a strategy how to replace the replacement in the future.

One important tool to do this, is detailed documentation of protocols (including timings) and semantics of the software.

Re:You need to come up with a migration strategy (1)

Osgeld (1900440) | about a year ago | (#43884151)

I work with this software, and too fast is not a problem, as its the PLC that runs the software, you just need to run the funky 20 year old uploader on something

Re:You need to come up with a migration strategy (1)

prefec2 (875483) | about a year ago | (#43884373)

For the PLC part this is true, if replacement PLCs do not have a different sampling speed. However, I was more referring to the control software running on PCs. 20 year old software do sometimes timing stuff based on CPU cycles and even if not, certain problems first occur when the software is executed faster. But, yes, this is only an issue for PLC scenarios, where PLCs and PCs are tightly coupled.

Re:You need to come up with a migration strategy (1)

inasity_rules (1110095) | about a year ago | (#43884543)

That is what I love about Omron. Upload the program from, say a C2H, and download it on a modern CJ CPU, and everything seamlessly and flawlessly just works. Plant downtime rangers from zero to 15 minutes.... Other PLC manufacturers are very decent too, but bloody Siemens breaks between PLCs of different sizes on the same generation. Bastards. And Toshiba is still on Generation 1.

Re:You need to come up with a migration strategy (1)

some old guy (674482) | about a year ago | (#43884611)

Siemens has sucked out loud in every imaginable way ever since they abandoned the old TI 505/Step 5 framework. Step 7 is grossly bloated for the scale it's good at, and fails miserably as a wannabe DCS.

Re:You need to come up with a migration strategy (1)

Osgeld (1900440) | about a year ago | (#43885535)

Theres too much speed viratity to be clock synced with a CPU 20 years ago, it was an obsolete practice 15 years before that

Re:You need to come up with a migration strategy (0)

Anonymous Coward | about a year ago | (#43884179)

Migration isn't always financially feasible. I was with a company that ran it's own 16-bit based software wrote in the early 90s. To create new software would have been in the tens of millions of dollars, something this small business could not have afforded. The solution was to roll out win 98 virtual machines. Saved the company millions and worked like a charm.

Where to Buy (0)

bgmacaw (2909193) | about a year ago | (#43884001)

At a company I used to work for we found that EBay was a great place to buy old equipment we required for our outdated, but still needed, systems (mostly to connect to scales and such). You do need to use a lot of caution when buying there since the quality of the equipment and the quality of the sellers vary a lot. There are also some sellers who have separate online stores where they feature a wider variety of items in order to avoid fees. You may also find someone who sells online also has a physical store location in your area. Visiting a tech graveyard store is a fun way to blow an afternoon. I do agree though with what AmiMoJo said, virtual machines and cost/benefit analysis is going to be better in the long run than trying to keep that IBM AT running.

Solution (0)

Anonymous Coward | about a year ago | (#43884009)

Never - ever - upgrade.

Moxa serial connection equipment (1)

stasike (1063564) | about a year ago | (#43884023)

A few posts ago I wrote about Industrial PCs.
If you need just a serial port, and not complete PC running old software that needs to access serial port directly, there are boxes from Moxa that let you connect dozens of serial ports to one PC.

16 Bit what? (1)

jfdavis668 (1414919) | about a year ago | (#43884027)

16 bit software. What OS? Windows 3.1? 2.11? OS/2? DOS? Xenix? Beside the RS-232 problem, finding new hardware for these OS can get difficult. As others stated, you can use VMs to run, but it would help us answer the question if you list the OS. Just finding old OSs can be quite difficult. (legally)

You're not alone (5, Informative)

mykepredko (40154) | about a year ago | (#43884029)

Hi Timothy,

Unfortunately, you didn't provide a lot of information in your post as to what the problems are.

As people have pointed out, there are a ton of USB to Serial solutions out there so having the modern hardware with the ability to communicate over RS-232 is generally not a problem (although, depending on the connections used, you might want to invest in a RS-232 breakout box and read up on RS-232 handshaking as many of the older devices do use hardware handshaking). I have a few hand wired 9 pin to 25 pin connectors with the CTS-RTS and DSR-DTR pins shorted together as they can simplify your life immeasurably.

In my experience, the biggest problem is retaining floppies & CDs with the original software on them (assuming that the developers are no longer supporting the product/are out of business). If the company is still in business, usually they're pretty good at providing updated software for their products. If they're not in business, then look to see if they were bought out by anybody. Chances are you'll find that the purchaser is still supporting the product, although it may be under another name.

Personally, the biggest issue that I see when I have encountered this type of situation is that the original programs are on floppies. If this is the case, you will need to find somebody with a Windows/95 machine that they're keeping together with spit, bailing wire, gaffer's tape and good intentions - you should be able to copy the program onto a USB key and then burn it on a CD/DVD for more permanent storage.

Once you have the program in a media that you can work with, you may have problems with the installation. You will probably have to create a virtual machine on your PC AND there may be 16 bit programs that you have to convert to 32 bit - here's a great resource that's saved me a couple of times: []

Finally, Google is your friend. Chances are the answers are out there for your particular equipment.

Good luck!


Re:You're not alone (1)

Anonymous Coward | about a year ago | (#43884173)

Once you have the program in a media that you can work with, you may have problems with the installation. You will probably have to create a virtual machine on your PC AND there may be 16 bit programs that you have to convert to 32 bit

No need. You can run 16-bit, or even 8-bit software in a VM. You may need to run it under something like Bochs instead of hardware assisted, but for software that old, full software emulation is not going to slow it down.

The bottom line - if it ain't broke, don't fix it. The fix can break it.

Re:You're not alone (1)

CAIMLAS (41445) | about a year ago | (#43884291)

'dd' (or rawdiskwrite, or whatever the Windows equivalent is) is your friend, as is virtualization. There is very, very slim rationale behind keeping these systems physical. Even SCO virtualizes OK in most scenarios.

Re:You're not alone (1)

toygeek (473120) | about a year ago | (#43884303)

For one application where a customer had to run an old 16 bit DOS application on a newer Windows box, I installed DOSBox (which is typically used for gaming) and it worked great. Mind you, it was a very simple piece of software and did not use rs232 communication, but instead was like a hard coded spreadsheet. A very specific, difficult to replace, probably no replacement existed, hardcoded spreadsheet. It worked great.

Re:You're not alone (2)

inasity_rules (1110095) | about a year ago | (#43884571)

USB to serial adapters are shit. +/-6V instead of +/-12V and variable latency (USB does not guarantee latency). RS232/RS485 to Ethernet adapters are far better, but nothing competes with a physical port for some obscure finicky equipment. And yes, it is still out there working fine unlike the modern rubbish that fails if the air gets slightly moist.

Use virtual machines (1)

woboyle (1044168) | about a year ago | (#43884137)

On a modern OS, such as Windows or Linux (preferable), you can use a virtual machine to run older DOS and such operating systems, passing the RS-232 ports of the host though to the virtual machine. Works great for me, and I use that for dealing with similar embedded systems all the time. FWIW, my preferred host OS is a clone of Red Hat Enterprise Linux (RHEL) 6, Scientific Linux (SL). CentOS is another such clone, and widely used in industry. I use SL because I personally know the maintainers of SL at Fermi National Laboratory in Illinois (my wife is a staff scientist/physicist there), so if I have an issue, I can contact them directly. My preferred virtual machine manager tool is currently VirtualBox (open source, from Oracle/Sun), but KVM will also work very well for this. That said, I prefer the GUI and configuration tools provided by VirtualBox.

This is a piece of cake... (0)

Anonymous Coward | about a year ago | (#43884165)

...we run two pick and place machine which run on CP/M daily. Replaced floppy disk (5") with emulator which runs on sd cards and everything works fine.

So, 232 and Windows is a child play :)

Risks (1)

martin (1336) | about a year ago | (#43884167)

All about risks, not just the fact the device is RS-232 only, but can the manufacturer support the equipment and if it fails whats the cost to the business while the machine is down.

Sure we can all get 486's with ISA cards if the device needs connectivity to the outside world, but the device of that is a business risk and needs Mgmt to be aware of the issue.
I've had a parts carousel system go down for weeks while we replace gearboxes, made worse by a switch from AC to DC by the manufacturer. Costs to the business were huge and all production was slowed down. Mgmt were informed of the risks but wouldnt spend any money till if broke.

Basically you're looking at a CYA situation, make sure mgmt are informed in writing (email etc) of the issues around the machines and what costs there are vs getting in new machines and added benefits of new machines

Keep a few older systems (1)

Anonymous Coward | about a year ago | (#43884233)

Ethernet and USB to RS-232 are great solutions, but sometimes software is written a little too specific to HW, like CPU clock speeds, system IO chips, etc., and it just won't run in newer OSes and virtualized environments. For that reason I've kept a few older motherboards and systems and I've had to run them from time to time- ISA slots, 5.25" floppies, even 3.25" floppies are rare for me these days but once in a while, needed. About a year ago a guy paid me around $200 to recover lots of files from some XT and AT class hard disks, and I was able to do it (fairly easily).

Everyone has "upgrade fever" but I don't necessarily recommend it. Often the 20 year old software is well written and works 100% in its correct environment.

A good friend of mine works at a company with just this problem. They have a very expensive CNC machine. The software is very hardware dependent- needs to see old AT architecture stuff, the original 5.25" floppy (software key), CPU clock dependent timing loops, etc. The whole machine was wearing out and needed so much overhaul, all new bearings, slides worn, etc., they finally scrapped it, but replacement cost hundreds of thousands. But during it's 25 year lifetime they kept some older PC hardware around for spares and kept it running.

It might be more cost-effective and time-efficient to find some older stuff on ebay. Maybe I should rent out my systems / services!

Some observations... (4, Interesting)

tlambert (566799) | about a year ago | (#43884253)

Here are some observations about why the problem isn't as difficult as you are making it out to be.

First and foremost, for older PLC hardware, the PLC hardware was considered to be the valuable part, and the software/drivers were considered to be overhead that they had to have to sell the hardware. So most of the serial protocols for these things were well documented in order to reduce support costs. In general there was either reluctant free support for their software/drivers, or you paid a fee per incident. If support contracts were an option ... you are unlikely to have kept the payments up this long. So you will likely be writing some code, but you will likely have documentation with which to do it.

Second, the FTDI drivers are crap. They leak kernel memory in Linux when you unplug them while the device associated with them is open. They also do this in the Windows Drivers, and because Mac OS X is religious about its encapsulation model in IOKit, unplugging them in Mac OS X while the device is open generally leads to a kernel panic. Almost all the USB-to-RS232C/RS422 adapters use chips sourced from FTDI, or use clones of the FTDI chips so they don't have to actually write their own drivers. Rampant code copying between vendors is my suspected reason that most of these vendors refuse to document their hardware well enough that an Open Source driver without the bugs could be written. You are unlikely to be happy with USB fobs.

Third, 9 pin RS232C is frequently not enough for a lot of older devices. The RS232C specification allows external clocking of the signal, but these pins are not present on the 9 pin connectors, only on the 25 pin. Additionally, there is out of band signaling that is sometimes used on other RS232C pins that aren't as frequently used that can be necessary. As you are with a printing firm, if what we are talking about here is an old Linotype or similar machine, you are likely to be SOL without full 25 pin RS232C. You should be happy that it isn't an 8 pin DIN cable from an old Mac, since at least you get the RI pin on the 9 pin connector.

Fourth, terminal servers often have these issues, in spades. There are a number of terminal servers where, if you have a blocking outstanding read on the serial port, outgoing writes are blocked until the read completes or times out. They basically expect that you will poll, or that all your communications over the serial port will be synchronous (i.e. you will not end up with output to your Wyse-50 until after you have input something). I can name a number of vendors with 8-port serial cards that have this issue. On the plus side, it's a driver design bug, so if you are swilling to use your own driver, or are willing to go Open Source OS, this is typically not a problem, but you will end up screwed by Windows and Mac OS X -- but a Mac OS X subclass of the broken driver is easier than an entirely new driver written in windows. Computone 8 port cards used to have this problem a lot.

Fifth, and finally, with USB dongles, it's frequent that the modem control signals are borked up. What I mean by this is that until the pseudo tty USB driver on the host side of things is opened, then the pins on the RS232C side of the adapter are floating in an indeterminate state which depends on the USB fob firmware, and is frequently not where you would want e.g. DTR or CTS/RTS or other signals hanging out for an idle serial port. This can make older equipment Do Things(tm), and the oly real remedy is to get the port open, set the signals right, and THEN plug in the serial cable. Generally, this means that you get to have two sets of signal state for setup, in addition, since the line buffers in some of the older devices are not optoisolated, and on those which are, the optoisolation can blow if you immediately apply voltage before ground, etc.. If you think talking to an old PLC is hard, try replacing an ancient Zilog UART on the damn thing.

Re:Some observations... (2)

Dadoo (899435) | about a year ago | (#43884443)

Third, 9 pin RS232C is frequently not enough for a lot of older devices.

That hasn't been my experience. I've been doing RS232 since the early 80s, and I've run across very few devices from that time period that use more than the minimum three.

What I have seen for devices that use the other signals is that they'll use them differently. For instance, the original RS232 spec uses RTS/CTS differently than they're used today. Also, pins will be used incorrectly; I have a computer in my garage that uses DTR for flow control.

Re:Some observations... (2)

inasity_rules (1110095) | about a year ago | (#43884619)

And 9 out of 10 USB to serial adapters I have run into can't even generate the correct pin voltages... +/- 6V might work for some devices, but not all. A lot won't see anything below +/-12V. Especially the 'comms powered' type.

Re:Some observations... (0)

Anonymous Coward | about a year ago | (#43884671)

Big deal, any 15 year old kid could rig up a gate to bring in exactly the voltage and interface would need. Perhaps you need to learn about that which you speak?

Re:Some observations... (0)

Anonymous Coward | about a year ago | (#43885047)

I've wired up plenty of converters to step up the voltage and make cheap usb-to-serial adapters usable for 12 V devices... at home. My employer wouldn't want me wasting time on something like that and would rather I just buy a dozen or more converters that work from the start and move on to doing actual work.

Re:Some observations... (3, Informative)

Lvdata (1214190) | about a year ago | (#43885347)

My ftdi on my arduino does have intermittent upload errors when used inside of VMware. I can live with it as it does a crc check. If your H/W S/W doesn't error check you might want to avoid that combination.

USB - serial adapters are cheap and easy to find (1)

Lisandro (799651) | about a year ago | (#43884283)

Just make sure you get one supporting the flow control lines, which most cheapo adapters don't. Most industrial equipment i've worked with wont communicate without those.

20 year old antique?? (1)

sir_eccles (1235902) | about a year ago | (#43884307)

Am I the only one laughing at the thought something from the early 90s is now considered antique?

Re:20 year old antique?? (1)

greg1104 (461138) | about a year ago | (#43884797)

Yeah, I was just blowing dust out of a not easily replaced original IBM PC from 1982 at a manufacturing site last week, and I sure wouldn't call even that antique.

Serial ports are a pretty easy thing to deal with. In PC land it's stuff on old ISA cards that are the real nightmare. One of those is what's keeping that PC alive, and we can't even replace the system with a newer model because the software is only timed right at 4.77Mhz. I'm just glad I don't have any MCA bus hardware to worry about anymore.

Re:20 year old antique?? (2)

plcurechax (247883) | about a year ago | (#43885329)

Am I the only one laughing at the thought something from the early 90s is now considered antique?

Ha, darn kids probably can't fathom the idea that there were real computers in use by companies and organizations before those flashy single chip microprocessor based PCs were all the rage.

No mention of minis like PDP, VAX/VMS (RIP DEC), CDC Cyber (12-bit bytes [] ), Data General [] , or IBM & Unisys mainframes.

Thankfully there was at least mention of Zilog's Z80, terminal servers, RS-422/485, and green screens.

Bunch of whiny kids. Next they'll complain their first automobile or hand-me-down cathode ray tube colour television doesn't have WiFi and a web browser. Get old my lawn.

Heck, I develop, maintain, and extend software that's over 20 years old. I've worked on software written before I was born. Software approaching 50 years old is more like what I would consider ancient. Like much of the insurance and banking industry in Europe and North America.

So. my serious bit: Learn about industrial computer market, products, and vendors. Use industrial USB to RS-232C converter in most cases (where timing or bit banging isn't used), not the $5 USB-to-serial adapter from the big box electronics store. Take a class from your local community college if PLC or ladder logic is relevant to your environment.

yes, me too (0)

Anonymous Coward | about a year ago | (#43884345)

A business critical piece of hardware that needed a custom 8 bit ISA card and Win3.11 to control it. Made sure I had multiple good images of the hard drive because the original floppies were lost. I was burning through old PCs that I kept in storage but found a supplier of 486 computers with ISA slots, so I bought two that I kept in a ready to go state. Thankfully that one custom card was rock solid.

Eventually (last year) the 25 year old machine broke and the company had to pony up the $50,000.00 for a new one which is also much more functional.

We also use lots of RS232. PCI cards from Comtrol have been the most reliable for us.
There are lots of USB-Serial cables, most suck. I only buy from FTDI.

You don't need Win95 to read floppies; USB floppy drives work fine. The real problem is that old floppies are almost guaranteed to be unreadable. As soon as you can copy all your floppies onto cd-rom. I use linux to make floppy images "dd if=/dev/fd0 of=floppy.img". Then they can be mounted, read, stored on cd-rom, used to make new floppies, etc.

Virtual Machines that support the older OS's (0)

Anonymous Coward | about a year ago | (#43884409)

Virtual machines would provide the bridge you need to consolidate the processing power on the newer machines with antiquity. You can even network a DOS VM. I love the old stuff, making what

One thing to try (1)

kilodelta (843627) | about a year ago | (#43884569)

Is see if the PLC manufacturer supports newer hardware/software. I went through this in a few places. Ancient systems in place to do a specific function.

But where I could I replaced them with more modern hardware and software. Sometimes I'd have to write the software myself but it got done.

What about a terminal server? (1)

Vrtigo1 (1303147) | about a year ago | (#43884639)

What about using a terminal server for RS232 stuff? There are plenty of them out there that are designed to give you a console connection to network gear. Seems like you might be able to hack something like this to make it work. Essentially you would load a driver on a PC that makes it think the serial port on the terminal server is a local RS232 port.

what's the problem? (1)

DogDude (805747) | about a year ago | (#43884679)

I don't understand the question. Why is running hardware via serial ports a problem? Serial ports have been included on almost every PC made for the last 30 years. I have plenty of serial port based hardware. You plug it in. There are literally billions of computers on the planet with serial ports.

Scavenging.. (2)

technos (73414) | about a year ago | (#43884881)

I had to support a manufacturing company 15 years ago that was using (at the time) 15-20 year old gear. I did it by scavenging and making it myself. Robot needs a new SSDD floppy drive? Flea market Commodore. RAM in the Soviet S100 clone going bad? Take apart a broken synth. Winchester drive controller going tits up? Drive around and look at all the junk bins of every computer shop in the county. Need to move a bit of kit but now the non-standard 45-pin cable is too short? Clip the ends off and Radio Shack them to RS-232. I also swapped a lot of gear around; The DOS machine that was used to program one robot was gradually upgraded from an 8088 machine to a 486 as I stole parts from it to keep the CP/M-86 one running.

The other thing I did a lot of was preventative maintenance. Blow out the dust, check the power supply, clean the disc drive, make sure everything is well seated. Switches got lubed, cables checked for faults, and media replaced.

one solution: piles of old crud (1)

swschrad (312009) | about a year ago | (#43884961)

the way they supported old lines at (major environmental controls company you've all heard of) was to keep all the old 286 machines and line printers in a back room the size of an 80s living room, and repair, repair, repair. label printing for boxes on the production line was old Printronics machines, which was the big headache.

All this is still possible on modern hardware... (1)

cianduffy (742890) | about a year ago | (#43884981)

...assuming your software can support being run on a recent 32 bit Windows properly

My employer has only recently taken off sale a re-shelled 1980s Object Pascal application that needed direct serial and parallel access and we were able to provide machines that handle it and the various peripherals perfectly well. Intel Reference boards (which they're withdrawing for PCs sometime soon unfortunately) and Startech PCI-E cards for the ports. I think the boards even have a floppy controller although the need for them was finally removed by an upstream supplier buying some CD burners a few years back.

Something written to work on 1987 grade hardware can sometimes run faster than intended on a Core i7, though.

Legacy systems maintenance and upgrade plan (0)

Anonymous Coward | about a year ago | (#43885045)

I am running into the same problem supporting legacy systems. Finding older systems that will support the hardware you need, i.e. EBay is what we use to find older control systems and other hardware. I have found some software does not work well in a virtual machine environment. The original software sometimes needs particular OS (i.e. older dos versions or specialized OS versions). Hard drives fail and can be restored from Ghost images. Installing obsolete and unsupported software and software keys are sometime difficult to impossible to reinstall, not to mention the data lost. Serial ports are still available but ISA card slots are obsolete and are hard to find on new hardware. There are repair depots that will repair just about anything. Cost and downtime are a big problem if the parts can be fixed.

Best suggestion is to start to plan an upgrade to newer controls. There will be a time that some older hardware will fail and you will not be able to fix it. You will be forced to upgrade hardware immediately. If you have a plan to upgrade, the down time and cost to fix are substantially less in both investment cost and downtime. The older programs can be rewritten or converted to newer controls. The programs can be rewritten and ready to install when needed. This upgrade can save a lot of machine downtime. We have used this upgrade model more than once. This has limited our downtime to a couple of days for wiring and troubleshooting. Emergency programming of PLC and operator interface panels are at best very expensive on an immediate time frame. Learning new programming languages can take a long time to program efficiently. Extended machine downtime can be more costly than planned upgrades. Our management has been more open about planned upgrades after the first major downtime disaster.
Good luck in the trenches

Emulator companies (0)

Anonymous Coward | about a year ago | (#43885109)

There are companies that specialize in emulating "legacy" hardware systems. This usually means VAX/Alpha/HP3000 machines. But there is no reason it couldn't also be old PCs running DOS. The company I am most familiar with is Stromasys, but there are others as well.

Industrial Ethernet Book (3, Informative)

D1G1T (1136467) | about a year ago | (#43885199)

One of the few marketing catalogues I actually use. Sometimes flipping through a book can show you products you didn't know existed. []

Buy lots of X40 series ThinkPads (1)

Enleth (947766) | about a year ago | (#43885255)

They are cheap, almost indestructible, small, low-power and ancient enough to comfortably run any legacy application out there, even under pure DOS. Should one break (which is, in itself, rather unlikely even for heavily used units), full service manuals are available and having lots of them means easy replacements. They have traditional, hardware RS232 and LPT ports, one of each. As long as you need a single machine for a single PLC, X40s should be one of the best tools for the job.

Support for old software should be required. (1)

pubwvj (1045960) | about a year ago | (#43885281)

Vendors, such as Apple, Microsoft, etc, should be required to continue to support older software in their new hardware and OS releases.

There is no excuse, except greed, for them to drop support for Classic, Rosetta, PPC, etc. The new hardware, even a lowly iPodTouch, can easily emulate the old systems by orders of magnitude. There is a tremendous amount of not just mission critical software such as the above article discussed but also simply good software like what came out of the hay-day of educational software programming during the 1990's.

Apple and Microsoft have committed cultural and intellectual crimes by dropping compatibility such that older software can't run on the new OSs. They have HUNDREDS OF BILLIONS (yes, I'm shouting) of dollars and could not just afford but should be required to provide backward compatibility.

If they plan to stop providing backward compatibility then they should be required to give up all copyright, trademarks and patents related to the hardware, OS and software and provide full documentation five years before they sunset it so that others can pickup the software, OS or hardware.

Windows98 VMs (2)

Deideldorfer (514118) | about a year ago | (#43885307)

I have two Windows98 virtual machines to support equipment requiring crusty old modems. They have been running trouble free for several years now.

use a moxa 6150 (0)

Anonymous Coward | about a year ago | (#43885467)

we use these at work

ethernet to serial they work very well for us

I could also use a hand with a quick followup ? (1)

LordNinja (2938373) | about a year ago | (#43885537)

I am actually working with such systems right now! I've been trying to remote into an HP 1000 unit over serial but can't get the hyper terminal settings right to send the break command over and get going, it call comes out as corrupted. What has your experience been with this? We have no documentation for the manroland folks/ HP so I've been digging around.. happy to get communication back over MUX 0 to even see nonsense coming back from the terminal... Perhaps I can't use hyperterminal or ADVLINK so... I was very frustrated and happen to see your post! What are the odds? I was hoping for some terminal settings such as flow control etc for these things but have had no luck! Mostly we have been trolling around online to find legacy vendors that have amassed the stuff, to respond to your question.

PLC? (0)

Anonymous Coward | about a year ago | (#43885679)

Public Limited Company? Define your acronyms, moron.

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