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Comment by leeter | Hacker News Reader

Reading this... my first thought was "But newer x86 can.... oh right ISA..." then I googled for USB ISA slots... and they are apparently a thing. That doesn't mean someone wouldn't need to write a new driver but at least they could still use the cards.

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Many years ago I was using an MCA (multi channel analyzer) ISA card connected to a surface barrier detector to measure beta decay spectra. This stuff basically counts the number of pulses from the detector binning them according to the height of the signal. It had its own acquisition software meant for DOS (the manufacturer provided the sources as well).

The thing is you could operate it under Windows (98) in protected mode, but then you lost statistics. How come? Well, Windows scheduling meant that the MCA only took data while it was allotted time slices, as a result the dead time of the whole setup increased, and you couldn't tell by how much.

Under real mode DOS it took advantage of DOS being almost an RTOS and the program running as a single task and you could be pretty confident about your data.

I don't think using adapters with this sort of cards is a good idea. It's not a matter of drivers, sometimes the old stuff simply doesn't work well when plugged in newer systems because everything has changed and you need to redesign everything. If the old stuff does the job, the OS being unsupported only becomes an insurmountable problem for the folks that consider using an unsupported OS some sort of crime in itself. Well, there's usually more than just an abstract computer being used in such circumstances.

Exactly. I believe someone tried investigating a solution to use a modern system and either perform some kind of pass through to a Win95 VM or some such magic, and it ultimately came down to needing to re-implement either the driver or the software, and that is hard to do without funding and time. Or any good documentation on what the original function and behavior was.

Yeah my first thought was just running a 16bit OS on modern hardware (it will do it if you're careful and do the right things). But then the issue of it being an ISA card popped up... that's not really a solvable problem with modern hardware unless you can convince an IHV to make you a custom motherboard. Although apparently some exist ( https://www.ibase.com.tw/english/ProductDetail/EmbeddedCompu... ) probably for industrial applications. While I'm very sure you could get DOS running on that... I'm less sure of Windows 95. The google search did show other options that are plausible but I doubt many of them would arrive working as is without needing capacitor replacement at a minimum.

There are all sorts of USB-to-Foo interfaces, the vast majority of which implement whatever Foo is just barely good enough to say it works with a straight face. Like the USB-Serial adapters...most of them work ok at 9600,8,N, but trying 5-bit with 1.5 stop bits (something a 'real' PC serial port can be persuaded to do) and good luck.

So, yeah, I'm sure that USB-ISA adapter probably works with that old 3Com ethernet card or that Soundblaster card that 'definitely' sounds better than anything else, but a custom card with custom software and probably unknown tolerance to variations from 'real' ISA? Good luck with that.

Oh probably and even if you did find one that works "well" you'd have to buy a ton of them to ensure you have backups. I'm well aware of the issues. But without an alternative or a grant to update the hardware what do you do? At some point the availability of period hardware with ISA slots is going to be prohibitively expensive.

You can still buy new manufacture motherboards with ISA slots and modern processors. Intel still (or until recently) made ISA bridge chips for modern Southbridge chips. And it's something that a smallish FPGA could handle. There is a whole ecosystem of companies that recreate old-style motherboards for exactly this scenario.

My brother's company does IT stuff for the manufacturing sector. Very conservative. I've worked with a number of his customers to source exactly this sort of thing. Years ago they asked my thoughts on an Italian made cloth dying machine the size of a bus with a DOS PC controller and a minimally documented ISA controller. A mid 7-figure US$ setup; the company that built it is long gone. We found a shop that supplied new motherboards, modern (at the time...P3/P4 era I think) with ISA slots the vendor guaranteed it would be every bit as slow and weird as a PC/AT. Migrated everrything over, the company bought a stack of motherboard spares new, and I think they're still using them.

Now...you want a challenge? Migrating the proprietary, mostly undocumented software, all in Italian (we aren't native speakers...though my high school Latin occasionally helped) from an old ESDI disk to something, anything, else. That was much more interesting.

Just like most USB-to-parallel adapters will only work with parallel port printers and not much else.

To save others a search: http://arstech.com/install/ecom-prodshow/usb2isar.html - about $145 each.

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