I am with Dr JBHL  The slide rule

Commordore 64 with a tape drive - whoop.

Then I had a the Compaq PI dont recall the model but the one with the faullty floating point calculations.  lol

You were in high cotton!!  All I could get my hands on was a Commodore VIC-20. 

mine I paid $50 for second hand  and mostly just to keep my recipes and family tree on, and play games hehehe. it was similar to this one, it was an early apple mac, b&w

I am old school. Back in my day computers didn't have screens. THey had teletypewriters... or a single line LCD! Ahem. First computer I worked on was a MITS Altair 8800. Yeah. I went there.

The first "computer" I bought was technically a calculator, but you could do a lot of programming with it. And I did. Nerd cred. The HP-41c, back when HP knew how to make good products.

My first "real" computer was the Kaypro II, a Z-80 based SUPER computer with a real color (all green) screen and two, count them two, single sided floppy disks and a whopping 64K of RAM. Smokin.

Sure, I did use a slide rule before that, and my hands before that. I even used an abacus, go figure. But, those are really mechanical aides not electronic computers. So, I'll stick with above list. I think this list makes me old...

Yeah, and that Hannah creature [read bitch] ripped you off severely.

That POC [read, mechanical turd] was worth no more than a couple of bucks at best.

Frankly, it was the sort of thing you'd tie around a banker's neck before throwing him off the pier.

My first computer was a TRS80 Color Computer with a stunning 16k of memory and cartirdges and a tape drive.  My first gaming system was a microvision.  I still remember those lcd blocks.

IBM 386... the one with the "Turbo" button! We had Windows 3.1 and mainly used it for Wolfenstein 3D, Commander Keen & Tank Wars.

...and the graphics was amazing! I remember when I overclocked it! Smoke was coming out of BOTH ends!!!

The first that I purchased was an Amstrad PC-6400, I believe it was in 1987.

Specifications:

• 8086 at 8MHz
• 640k RAM
• One or two 360k 5.25" floppy drives; optional hard drive
• MDA, Hercules, CGA, Plantronics or EGA display compatibility
• MDA, CGA or EGA monitor (power supply is in the monitor)
• Four full sized 8-bit ISA slots (one hidden inside the case; the other three in the expansion bay)
• Battery-backed real time clock
• 75-key keyboard (XT-style, function keys on the left)
• Amstrad CPC-compatible joystick interface
• Software: MS-DOS 3.2, GEM 2.0, BASIC2 1.21

Sinclair ZX Spectrum with a staggering 48k of RAM, back in 1982 IIRC.

Like Quicksilver007's ZX80, you plugged it into the back of your TV and storage was an audio cassette.

Also had the Sinclair printer which used rolls of metallized paper - an electric spark zapped the coating to leave a black 'pixel'.

Print head was a metal stylus mounted on a toothed drive band.

Didn't do much with computers at the start of Uni, it was a Casio Fx7000 calc that got me back into programming.

Taught myself C on an Acorn Archimedes A5000 with RISC-OS3, 25MHz ARM3 processor + FPA10 maths co-pro, 4Mb RAM (2Mb ROM for the OS) and 40+240 Mb hard disks.

The Arch also had a 386 PC card so you could run DOS/Windows 3.1 inside a window on the RISC-OS desktop.

A gateway I bought in 2005 was my first computer.  I'm on my second one now!  

I purchased and used an Ohio Scientific in 1978 for personal and business purposes.  Here is a partial list:

C8P DF GT
 Microprocessor - 6502C   4Mhz. (GT option)
 Ram               - 48k  150ns. (GT Option)
 Disk                - 2- 8" floppies each 170k
 I/O  Video Board 64 x 32 Colors
 1-RS232 Port (Software addressable to 2 connectors)
 Sound Output
 Home Security Interface BSR Remote control
 Hi Speed DAC  C8P-DF-48k
 2 Joystick Inputs GT Option

Expansion Serial RS232 Board CS-10-2
48 Line Parallel I/O  CA-21
D/A, A/D CA-22
 16 Channel input multiplex to one A/D
 2 D/A
 6 TTL Input
 2 TTL Output

Serial Terminal AC-07C
 Haziltine 1420
                 Total Price $7,815.00

Lots of software.
 OS-65D V3.2, OS-65U V1.2, HC-1, HC-2,Graphics 1, Plot Basic, DAC1,PD 1-2, ED 1-4, BD 1-3, GD 5-10, WP6502U, WP3-2, WP3-1, OS-DMX, OS-Inventory, OS-DMS, OS-65U V1.42 - CD74 CD-36 MOS for Business, Demo Disk, Customer Demo, Dealer Demo.

I used the system for word processing and BASIC development for the company I worked for. I programed a customer equipment reception, tracking, and billing system.  This required hacking the OS to remove the 'LF' at the end of each write to the serial terminals so the text could be kept at the same location and be updated.  Great fun.

I sold this system to my nephew in 1984 after purchasing an IBM PC with an after-market 5 meg HD by Devong.  I had to keep a floppy in the floppy bay for the computer to boot to the HD.  I couldn't believe all the room I had to store stuff in.  It was so nice not to have to swap floppies all the time anymore.  Four years later it was an IBM XT with a 10 meg HD, two years later I upgraded the HD to 20 meg.  Then I moved on to after-market PC's.  One from some place in Texas, then another from Micron that I had for years.  Then I started to build my own computer for myself and firends.  I am on my fourth rebuild now and am starting to get itchy to upgrade again. 

William

I'm always itchy... just finished my 5th upgrade/rebuild since 2005.  It's sweet... and fast, moreso in Win 8

My first computer was a cool commodore 64 portable with a tiny little built in color monitor.

I played Zork games, SSI games Pools and Curse, last ninja, Impossible mission, Jump man, and my personal favorite text game Leather Goddess of Phobos. It had scratch and sniff cards that you were instructed to smell at certain points during the game like finding a old slice of pizza on the floor of the bathroom.

Radio Shack Color Computer (or CoCo as it were)  Had chicklet keys and you had to hook it up to a little TV for a monitor.

Used a tape drive that constantly failed.

It was good for learning basic and assembly.  I have fond memories of the hours wasted retyping stuff that wouldn't load.  Yeah, good times.

I think this is an exercise in age verification.  It wasn't "my computer", but I started on a mainframe that had to be housed in a separate refrigerated building, while learning COBOL at college.  Programming was done on punch cards (keep those suckers in the right order).  My very first computer to own was an Altair microcomputer, that I paid around $500 for in 1975.  It was followed by a Commodore PET.  I sold my first commercial business program to a sign company that I wrote on a Texas Instruments TI-99-4a.  Somewhere in there, I also had a Timex Sinclair 1000 with a whopping 2K of RAM. Okay, so has anybody seen my walker?  I am having a senior moment. 

Hooray ! ... someone besides me has had the guts to admit that they once owned a Commodore PET computer.   I feel so much better now ... Thank Goodness ! ... This reminds me, BTW, what a horrible case of "Apple-Envy" I had, when I first met someone who owned an Apple IIe ... Interesting days, indeed !