Atari 400 versus 800

Last Updated on November 25, 2022 by Dave Farquhar

The Atari 8-Bit line is the most underrated 8-bit computer. And I’m biased. I’m a Commodore fan going way back. I’m not supposed to like Atari. The 400 was the low end of the line, and the 800 was the original high end machine. Atari expanded the line over time, but let’s look at the 400 versus 800, the first two machines in the line.

What’s in a number?

monitor stand for retro computers
I didn’t grow up with an Atari 800 but I keep one set up right next to the machine I did grow up with.

The 400 and 800 are references to the amount of memory, sort of. Originally, they intended for the 400 to ship with 4K of RAM and the 800 with 8K of RAM. But memory prices were coming down, so how much memory each machine shipped with depended on when you bought it. Initially it was 8K with both. Eventually Atari bumped it to 16K in the 400 and 48K in the 800, as memory prices fell.

More importantly was the expansion capability. The 800 could easily be expanded to 48k of RAM. The 400 expanded to 16K of RAM, at least officially. Unofficially you could expand it to 48. More on that in a bit.

The keyboard

More visibly, the keyboard was different. The 800 has a nice keyboard. The placement of the Return key is a bit odd by modern standards, but it has nice key switches and it’s smooth to type on. It’s not an IBM Model M, but I find it similar to typing on an Apple IIe keyboard, and that’s no insult. Both have a nicer feel than the Commodore 64 keyboard.

I know the keyboard on later Atari models wasn’t as good, but the 800 had a nice board.

The 400 has a membrane keyboard. It looks like 1979’s idea of something futuristic. So you either think it looks awesome, or you’re wrong. But if you have to type on it… Ain’t nothing awesome about that.

Setting up the two machines side by side, especially with a word processor up and running, what have been an effective way to sell the 800.

Video output and cartridge slots

Atari 400
The Atari 400 looked neat but the keyboard was not at all nice to type on.

The 800 had a composite and s-video output. That means with the right cable, you can connect it to a TV with s-video, or to a Commodore monitor that accepts separated composite and get a better picture.

The 400 only had RF output. That’s more important today than in 1979, but a composite mod is available for the 400 to make it more useful now. You can connect a 400 or 800 to the RF input on a TV using an RCA to F adapter and tuning the TV to channel 2 or 3, just like a 2600 game console.

The 800 has two cartridge slots as opposed to the single slot in the 400. In practice not much was ever produced to use that second slot, and later models lacked the second slot, so its absence in the 400 isn’t much of a problem.

Otherwise, the same machine

But other than the keyboard and the memory and video output, they were the same machine. They had exactly the same 6502B CPU running at 1.79 MHz, exactly the same custom chipset for graphics and sound, and they were completely compatible with each other. The only exception was if you had software that needed 48k of memory.

And it was a great chipset. Even though it came out in 1979, it could hold its own with the Nintendo NES, which was as much newer design, dating originally to 1983.

Pushing the 400

If you were looking to buy a home computer between 1979  and 1981, the Atari 400 or 800 were the best all around choices. And if you could afford the higher price of $1,000, the 800 was clearly the better machine.

But even before inflation, it was a lot of money. As much as the $550 price for an Atari 400 sounds like today, after you adjust for inflation, it’s over $2000 in today’s dollars. The Atari 400 was an entry level machine, but even an entry level home computer was a major purchase at the edge of the 80s.

So the temptation was certainly there to buy the 400 and try to upgrade it. In the end it would probably be cheaper. Even if not, the upfront cost was lower, and then you could upgrade the keyboard and memory as your budget permitted. It was a lot better than a payment plan, at sky-high 1980 interest rates.

A number of people did exactly that. They soldered additional memory chips onto the memory board, running additional wires on the motherboard, and expanded the machine as far as 48k. In 1981, Intec Peripherals released a 48K upgrade board to make it easier. Today, you can buy a 48K upgrade board made from modern components.

And some people hacked together proper full travel keyboards to replace the membrane keyboard. Several  commercial replacement keyboards appeared over the years. Microtronics released a keyboard upgrade in 1983, priced at $129. Inhome’s rival B Key keyboard sold for $119. A third company, ATTO SOFT, sold a keyboard it called Version 2. For a modern solution, you can get a TKII, which allows you to plug any PS/2 keyboard into your 400. Or there’s the MX Profile Atari 400 mechanical keyboard, which uses Cherry MX-style switches.

So you will sometimes find heavily modified Atari 400 machines. The keyboard is a more visible upgrade than the memory, although it’s anyone’s guess which upgrade was more common.

My Atari 400 and 800

I have one of each model. Talk about a lucky break. It was 2006. I was running between estate sales, and my wife was hitting garage sales. She had a cell phone with her, but I didn’t. We only had one cell phone between us at the time. So when I got home, she told me about a garage sale that had a bunch of old computer equipment. I went looking for it, but either they had closed up, or I wasn’t understanding where it was.

A year later, we were out doing the same thing, and she went to the same house, and the same stash of computer equipment was still there. There’s no way that would happen today.

That time we didn’t let it slip away. I ended up with both machines, a cassette recorder, some software, and a few other odds and ends, and at what seemed like a reasonable price. In 2007 it was anyone’s guess what this stuff was worth. The owner was probably 20 years older than me and had no use for the machines anymore and was happy someone was interested in them.

Over the years I would get one or the other of the machines out to mess around on from time to time, but I don’t think it was until 2019 that I had room to permanently set one up and really appreciate what I had. By then, I was able to get a solid state floppy drive emulator, and that was the first time I played M.U.L.E.

The C-64 will always be my favorite machine because it was my first, but the Atari 800 is my second favorite 8-bit machine.

If you found this post informative or helpful, please share it!