duh... you didn't specify a place for "other"! paper tape was my "OS". 1975. S100, 8 bit bus. smokin. I upgraded it to Zilog Z80. doubled the speed but it had the same instruction set. the "monitor was a converted 8" b/w Sony. keyboard hand made with Cherry keys. I actually invented a coupla games, my kids & I played it for hours but the misses had no clue whatsoever. started in digital in early 60's (RCA). this thing had a 10 amp, 5VDC PSU that I thought was awesome compared the woosy Altair. first "real" computer was DRDOS based (blew MSDOS away). 286. I don't remember much about it. the same Guy that invented DRDOS was my first real OS (by Gary Kildall)... this guy musta had a 200 IQ. hey give me just a little of that!

DGT-100, a TRS-80 clone assembled and sold here in Brazil 1982/83 IIRC.
http://old-computers.com/museum/comp...sp?st=1&c=1174

It was an Eagle personal computer (PC) running CP/M 2.2 ...
Then a Tandy model 4P running TRSDOS 6.21, and a TRS6000 running TRS-XENIX, a Tandy release similar to SCO-XENIX

My first "computer" was, of course, a "log-log-decitrig" slide rule. That is, of course, and analog computer.

If you want to restrict replies to digital computers, there's the binary adder I constructed from relays scavenged from a discarded pin-ball game as an science fair project 8th grade. That was in 1954.

My fist computer was a Commodore PET (Personal Electronic Translator). It was the advanced version - it has n 8008 processor. The early version was 4004. The PET used an AUDIO recorder for storage and used the BASIC language. It had an IEEE488 output only. A friend of mine worked with Commodore to make the IEEE488 bi-directional and actually used the PET to control test equipment. I designed and made the hardware to convert IEEE488 to Centronics printer. I paid $1,000 for the PET used, which came with a lot of games. I STILL HAVE THE PET.
If you are ever near Mountain View, California, visit the Computer History Museum. A very complete display with very knowledge docents.
fkiss

TRS-80 Model III - and I had to add a RS-232 card for a 300 baud modem. This is when I got started with the BBSes. Later had to write my own term program in assembly to be able to upgrade to a 1200bps modem.

Our first computer was a Microbee, used by primary schools at the time. Ran everything off a floppy disk.

I checked "IBM Compatible" since it did use MS-DOS. It was a homebrew from The Bit Bucket, then in Cambridge (I think) Mass. Maybe it was Newton. It was sooooooo long ago.

The Amiga 1000 when it first came out, which I hotrodded with 1.5mb of ram and wrote MC68000 assembler for replacing the 'C' coded serial hardware interrupt handler. Mine worked much better than the bloated and slow AmigaDOS library call.

I learnt about executive privilege from Motorola. Really loved the unhinged multitasking too, it was a great place to learn the basics of modern Linux without all the additional complications of multi user environment handling

Then I got a SCSI expansion and wrote code for the SMIDI dumps from the Peavy SP and Kurzweil K2000

IMSAI 8080. I may even still have it in the garage, or the public storage.

First PC was a 640KB clone of the old IBM PC. I remember it as being a whole-lotta soldering. Wound-up having to bootleg the BIOS ROMs from a genuine IBM to get IBM-DOS working, since it wanted cassette BASIC in ROM to load-up. That one got sold, after I swapped-out the uP with a V20, to finance another project.

Those were the days.

Damn-right it did.

First secondhand was for a short time a Commodore VIC 20 1983 2 years later 1985 bought a new Commodore C64 with a cassette rec AND FOR THOSE WHO KNOW IT The red little Power cartridge box with extra special tools on the right backside.

Mine was a Carry 1 - 10MHz 8088, 256Mb ram, 2x 3.5" floppy drives, & a paper white 9" CRT monitor, which cost £500 in the 1990's.
(Operating System extra.)

My first computer was a Dan (I should probably have clicked "IBM-compatible" rather than "Other"), running Slackware 1. Computers at work up to then had been IBM 360/370 (Fortran IV and assembler), then Prime (Fortran IV), then Sun (C).

My first computer was PC with intel celeron 300MHz
You could "almost" watch graphics and video on it