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More than two hard disks in DOS
- philipstorry 1y agoQuite the nostalgia blast for me! I'm honestly not sure I had a machine with more than 2 fixed disks until well into the days of Windows 7 and SATA. The exception would be logical disks such as Stacker or similar compressed volumes - but I wasn't using them until later either. If I recall correctly before SATA we had IDE which only had two devices (primary & secondary) per controller, and usually only two controllers on a motherboard. Given the physical size of disks even you'd probably just have a boot disk, maybe a data disk and then perhaps two optical drives. So it's absolutely believable that nobody found the bug simply because nobody had a machine configured that way. Sure, you could have SCSI for more disks. But if you did, then you were probably doing something that required a lot of CPU grunt - at which point you might just leave the PC behind and go to a UNIX workstation anyway. OK, now I'm starting to get flashbacks to just how bad SCSI support was on the PC, and it's stripping the the rose-tint from my glasses. Time to go!
- jmclnx 1y agoI had added a 2nd disk on my 386sx, but I guess it was after the DOS 5.0 time. I did not realize before v5 it was not allowed. Not long afterwards I ended up on Coherent OS, fun times.
- dardeaup 1y agoThere were also MFM and RLL hard drives. I don't recall if they were pre-IDE or something different altogether. It's been a long time.
- mrspuratic 1y agoI used MFM in the first PC I built from scavenged parts, it used an ISA MFM controller card. IDE came later, those had an integrated controller ("integrated drive electronics") so the PC didn't need to know how to do the low-level control for the drive. Luxury. And less jumpers to faff about with.
- c0nsumer 1y agoYes they were. IDE stands for Integrated Drive Electronics because the drive could be connected directly to the ISA bus, using an on-board controller, vs. having to use an MFM or RLL controller on the bus in between it and the disk.
- cestith 1y agoAlso ESDI.
- pjmlp 1y agoAnd expensive, really expensive.
- lenerdenator 1y agoI was gonna say, "MORE THAN TWO HARD DISKS? IN THE DAYS OF DOS?! Anything else we could get for you, your majesty?"
- forinti 1y agoI have piles of old, but still functioning HDs now. I was looking at them yesterday and thought about how cheap these things have become. I had to save up to buy floppies in the 80s!
- rwmj 1y agoNot to mention the weight, power demands and (to some extent) noise! At one point I did have two hardcards plugged into my Amstrad 8086 machine which felt pretty decadent. (Or maybe it was a hardcard plus the internal hard drive?) In total it wasn't even 100MB of storage. https://en.wikipedia.org/wiki/Hardcard https://en.wikipedia.org/wiki/Hardcard
- cestith 1y agoThat, and the IBM PC 5150 had what, 130 watts?, in the stock power supply.
- Telemakhos 1y ago> before SATA we had IDE I had the original IBM PC with two 5.25" floppy drives, and I think that was all the room there was on the disk controller. Dad bought a 10MB Hardcard to expand it; that went in an ISA slot, if I remember correctly. The disk controller might have been in an ISA slot, too. I think that pre-AT era would have constrained DOS <5.0 more than the IDE/SATA/SCSI eras.
- kalleboo 1y agoI had 3+ fixed disks somewhere around 1997, but that was on a Mac (so built-in SCSI), and the drives were all hand-me-downs that I got for free, that I could just plug and play to add a few more hundred megs of storage.
- tempodox 1y agoIf 640 KiB of RAM was all anybody would ever need, what were they going to do with more than two hard disks?
- theamk 1y agoYou can never have too much space. Plus, as better disks appeared, older disks became much cheaper (or even free in some cases). It was pretty simple to collect a few of older, smaller, drives and stick them all in one machine just to give it more space.
- bombcar 1y agoPeople laugh about that, but when you look at when the whole thing was designed and came out, and how much it would have cost to have a "pimped out" system that pushed the limits (if even possible!) it becomes much more reasonable. Nobody expected this silly machine to be relevant and affecting computing 44 years later! It came with 16KB of RAM! 640KB would have been 40 times as much - that's the equivalent of a modern laptop (which comes with checks Apple 16GB of RAM) going up to 640GB of RAM. The original machine had support for two floppies and a tape drive - the first hard drives were in the 5MB for $2000 in 1982 range. That's about $6,700 today. Even the writings of the day assumed that the IBM PC would last "for a time" like all previous machines had, newer ones would come out on new chips that were completely different. Nobody really expected backwards compatibility and Windows to eat the world.
- forinti 1y agoFor the applications that were really important then (spreadsheets and word processing) even 64KB would be reasonable for most people. With 640KB you could run a medium-sized business.
- bombcar 1y agoI loved the HP200LX just for that reason - it was a hand-held 90s palmtop that was a full-fledged 186, with DOS 5.0 and "multitasking" and about a meg of RAM - and it could run ANY of those 80s programs, including a full Lotus 1-2-3 spreadsheet. That power - phenomenal, especially in the early Internet age.
- blueflow 1y ago> ... was missed for years simply because no one had a PC with more than two hard disks. Thats a hardware limit: Early mainboards only had a single IDE / parallel ATA port. Each port has two pins for drive select, so you had a maximum of two addressable drives, the master and slave drive. With a secondary ATA port you got another set of master/slave, pushing the limit to 4 drives. That's where the "primary master" text comes from that showed up on the screen during booting.
- st_goliath 1y ago> Early mainboards... ... like in the PC AT, PC XT[1] or the Compaq DeskPro 386[2] that the article discusses didn't have those ports at all. Those were instead on ISA expansion cards, just like the floppy controller that would often share a card with the UART controller for the serial interface. [1] https://theretroweb.com/motherboards/s/ibm-xt-type-5160-64-256kb-6323560,-6323362 https://theretroweb.com/motherboards/s/ibm-xt-type-5160-64-2..., [2] https://theretroweb.com/motherboards/s/compaq-deskpro-386-20-p-n-000749-001421-002 https://theretroweb.com/motherboards/s/compaq-deskpro-386-20...
- accrual 1y agoYes, the earliest mainboards I know of with on-board I/O including ATA is around Socket 5, the first mainstream Pentium boards. Some slightly older Socket 4 boards (circa 1994) have on-board I/O, but they weren't as common. My 486 and earlier systems have all I/O provided by ISA cards, other than the 5-pin DIN keyboard port which was standard since the original PC.
- roryirvine 1y agoI remember my dad's Dell 486P/33 from 1991 had integrated IDE, but that was a fairly high-end machine at the time (the forerunner of their "Precision" workstation range). Details here: https://theretroweb.com/motherboards/s/dell-system-486p https://theretroweb.com/motherboards/s/dell-system-486p But, yes, most bog standard machines would've had a separate "SuperIO" card containing serial, parallel, and IDE interfaces until the mid 90s.
- mikeytown2 1y agoSound Cards with IDE ports for CD-ROM drives were definitely a thing back then
- Zardoz84 1y agoYeah! I'm trying to get a Sound Blaster 16 with IDE + a VESA IDE controller working on a 486DX2@66
- cestith 1y agoThere were also a number of sound cards that had two or three ports because a lot of early CD-ROM drives weren’t IDE. You’d have a Sony, a Panasonic, and something else on your card in the early days. IDE on a sound card was an actual improvement.