I am surprised by the assumption that each box could only handle one modem. I seem to remember that some DOS BBS packages could handle multiple modems/users concurrently and only needed multitasking operating systems for “door” programs. Am I misremembering?

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EvanAnderson 6 hours ago | parent | next [-]

A guy who was local to me, when I was a kid, wrote multi-user BBS system (called "MUBBS" originally-- I don't remember what the name was changed to later) in Turbo Pascal that had a preemptive multitasking loop running in x86 real mode to handle multiple lines simultaneously. The coolest part was the console was just a "line" so you could logon to the board and interact while somebody was online with the BBS, too. Most other DOS BBS packages were only available for the SYSOP or the caller individually.

Edit: Ugh... I'm gonna have to go back to floppy images to find it. There's a "MUBBS" for Mac from 1992 showing up in search engine results but that's not the one I'm thinking of. It was more like 1989 or 1990.

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layer8 6 hours ago | parent | prev | next [-]

Some details/speculation from the original thread here: https://news.ycombinator.com/item?id=30098186

“as modems got faster, supporting 16 modems on a single machine became impossible, and it was often cheaper to buy a new commodity desktop PC rather than a much more expensive machine with a 16-port serial card capable of handling the IO.”

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nickdothutton 7 hours ago | parent | prev | next [-]

Even for a standard PC, you could buy a 16 port serial card and hook it up to 16 modems, either discreet devices or the dedicated ISP kit which might support dozens of incoming calls (possibly on a single bearer) via various means. Telebit netblazers and then ascend maxs were common in those days.

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icedchai 7 hours ago | parent | prev | next [-]

I'm fairly certain you are correct. I remember the MajorBBS could handle multiple lines on its own.

I knew a couple of local DOS BBSes that ran multiple lines with PCBoard under DESQview.

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EvanAnderson 7 hours ago | parent | next [-]

For sure. I knew people who ran multi-line BBS's on DOS PCs under DESQview, just like that (running Searchlight BBS, in my case). I know of a four line that was just using multiple external modems and non-standard IRQ's for COM3 and COM4 (since, by default, COM1/3 and COM2/4 share an IRQ).

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ghewgill 7 hours ago | parent | prev | next [-]

MajorBBS could handle multiple lines on its own, but you had to handle ALL of the lines with one box. That meant a serial port interface like DigiBoard which provided some number (8 or 16 or more) of serial ports that you would connect to modems.

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jamroom 3 hours ago | parent | next [-]

Yep - I ran a 16 line Major BBS back in the mid 90's in Seattle - used what was called a "Bocaboard" - had 16 serial ports on it - plugged in 16 external USR 28.8 modems. It all ran off of one PC.

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icedchai 7 hours ago | parent | prev [-]

I remember DigiBoard from my early ISP days. We attempted to turn a mid 90's-era Linux system (Slackware) into a terminal server. The Linux drivers for DigiBoard weren't quite up to it so we wound up going with Telebit Netblazers, I think.

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kstrauser 7 hours ago | parent [-]

I think we used RocketPorts for a while until switching to Livingston Portmaster 3s, which you plugged a T-1 into.

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icedchai 7 hours ago | parent [-]

Portmasters were very popular. Later on the ISP I worked with moved on to Ascend boxes which had digital modems (T1 / PRI lines.)

PRI was a huge step. The "individual modem" days were a mess. Each modem had a serial cable, phone line, and power brick. I remember doing some maintenance in one of the POPs. There were at least 100 modems, stacked on a cheap plastic shelving unit. The shelving unit was sagging from the weight and heat of all the modems.

This early POP was haphazardly built, so no cable management. I remember a river of phone cables coming out of the wall. The power bricks were also crazy. We had power strips 2 or 3 levels deep, making it a hazard to even get behind the rack without tripping on something.

	▲	kstrauser 6 hours ago \| parent [-]
		They'd already switched to PRIs before I started so I missed out on that "fun", but I can personally vouch to the younguns here that every word you just wrote was completely plausible and likely.

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6 hours ago | parent | prev [-]

[deleted]

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js2 7 hours ago | parent | prev | next [-]

Even the Apple II had multi-line BBSes[^1], so I'm not sure about her assumption.

[^1]: e.g. https://en.wikipedia.org/wiki/Diversi-Dial

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henrikschroder 3 hours ago | parent | prev | next [-]

I don't think those boxes had a 16550 UART...

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7 hours ago | parent | prev | next [-]

[deleted]

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cmpb 7 hours ago | parent | prev | next [-]

That assumption feeds into the moral of the post and its followup

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j45 7 hours ago | parent | prev [-]

Serial ports are a fun thing to learn about, computers had more than one. Now with USB, computers can have many serial ports.