The Granddaddy of Atari Computing - the Atari 800

In this video I introduce the granddaddy of Atari computing, the Atari 800. This computer (along with the 400) led to the longest lived (in production) Atari computer architecture: 1979 - 1992.
#retrocomputing
#vintagecomputing
#atari
#atari800
#atari8bit

[@JD-tf5tm]

i mowed countless yards to get the 800, disk drive, modem, etc. as a kid - i spent thousands of hours on this machine - loved it.

[@powerofvintage9442]

A common story...I worked and eventually begged for an Atari 800xl and got a 520ST. Loved the ST too, but part of me still wanted the 800xl (because that's what my friends had)

[@johnhunt1725]

Not only was this the "granddaddy of Atari computing", as Jay Miner's first computer design, it was also the direct ancestor of the Amiga.

[@powerofvintage9442]

Exactly, Atari and Amiga do share this interesting lineage….

[@ecdhe]

Actually several concepts introduced by the VCS (also designed by Jay Miner) were improved upon with the Atari 8-bit and then the Amiga.

[@winstonsmith478]

The 1981 series in Byte Magazine entitled "An Introduction to Atari Graphics" led me to buy the cheaper Atari 400 which, until the 800XL came out, I modded with a full-travel keyboard and used output from the joystick ports to drive a Trendcom 40 column thermal printer to print my assembly language listings made with my Atari Assembler/Editor cartridge. In combination with a cartridge PCB I depopulated and modded with some 7400 series IC electronics, I used some assembly language software I'd written which loaded from my cassette storage to dump carts to tape with an assembly language boot loader prior to the dumped code. I had correctly surmised without ever having to disassemble any ROM code that cart copy protection simply wrote to a location which should have been in ROM and if it changed, the code knew it was in the RAM "below" the ROM address space and wouldn't run, so writing to RAM there was simple disabled by the hardware on the cartridge. I did it simply to do it and only dumped carts that I owned as a test. Yes, really. After the 800XL in which I expanded the memory using plans found in a magazine, I bought a 1040STf with color monitor. I wanted an Amiga 1000, but with monitor it was much more expensive than the 1040 and by the time the A500 came out, I was heavily into the 1040. After that I went to PC clones I've built myself to this day, always using AMD CPUs along the way due to their price/performance, the first one being the Am386DX40. My first "computer" was the outstanding Heathkit ET-3400A microprocessor (MC6800) trainer, followed by a ZX-80 kit, followed by a VIC20, followed by the Atari 400. And there is more than anyone wanted to know.

[@mikewest6569]

Got the 800 in early 1980. Best 8-bit computer ever made .. it had everything.

[@powerofvintage9442]

In 1980 it was the most capable home computer available!

[@sedate4lyfe243]

I mowed lawns & sold fireworks to get my 800. Played many a game of Ultima, Caverns of Mars and Star Raiders on it. Learned Basic and Machine on it too. Ahhh nostalgia for when floppies were actually floppy

[@leoc.9341]

M.U.L.E. is my favorite game of all time, so I was happy to hear it was also one of your favorites. I was too young to get into computing in the 70's, but as a young teen in 1983, I joined the C64 crowd. It wasn't until last year that I discovered M.U.L.E. was first released on the Atari 400/800. That got me interested in the original version version and the port somebody did for the Atari 5200 (which is very similar to the 400/800 computers). While doing research, I was very impressed with the 400/800 computers. Especially when you consider they preceded the C64 by several years.

[@powerofvintage9442]

The multiplayer aspect of MULE is just plain awesome of which I have many many memories.

[@leoc.9341]

@@powerofvintage9442 On the opposite end of that spectrum, I was absolutely fascinated that I could start the game with all computer controlled players. Then sit back and watch them complete the game. At the time, M.U.L.E. and Archon were the only games I knew of that could do that.

[@powerofvintage9442]

@@leoc.9341 lol! didn't even think about that other than watching the computer demo of Archon if you don't start playing after a while.

[@ecdhe]

As someone who had an Atari 800XL, I played M.U.L.E. with three players using the Atari paddle controller on the second joystick port. And this was one of the best memories I have on that machine.

[@powerofvintage9442]

@@ecdhe wait! so how do you play with the paddle? Do you share the joystick during turns and use the paddles for the auction part?

[@8bitrocketstudios]

The Granddaddy of Multimedia Game Specific Hardware, the Atari 800, was my first computer and it rocked then and still rocks now.

[@rabidbigdog]

My Atari 800 (and then 800XL) got me through university. I used my own 80-column software as a terminal back to the campus VAXen. I didn't have need for a more 'powerful' home computer until the early 1990s and (luckily) jumped straight to Windows NT (on Alpha!).

[@powerofvintage9442]

In my experience collecting older computers, the majority of use cases for home computing (word processing, spreadsheets, games) haven't changed tremendously with the one major exception being the internet and media consumption (replacing the TV of the 70's and 80's effectively)

[@rabidbigdog]

@@powerofvintage9442 Spot on. We literally had a client who used Apple II Visicalc into the early 1990s, It just did everything they needed and they'd also written their own Basic-based databasing software.

[@transitengineer]

This was my first purchased home computer in the early 1980's right after receiving my BS degree in Electrical Engineering and, I used it for many years. These units were truly, built like a tank! Kept mine stored in a closet for about a decade then donated it to my local Goodwill. Today, I wish it was still at my home because it would be able to provide me daily, with hours of retro fun (smile...smile).

[@powerofvintage9442]

If you're in the US, 800's can be found at a decent price if you're patient. Otherwise, 800xl's are pretty common place and can be picked up pretty easily. They are still also pretty well built and I've had really good luck with the around 10 or so I've picked up and refurbished.

[@kjakobsen]

I like to see the history of Atari computers.I was a Commodore guy, and never knew about Atari at all. Don't think they was around in Denmark back then.

[@powerofvintage9442]

Thanks! I'll look into drafting something up.

[@theroguetomato5362]

It was my first computer. I got the 6502 assembler ROM and, just for the fun of it, I'd crack the ROM copy protection on games and put the ROMs on bootable tape. Never did anything illegal like sell or share the cassettes, but it was fun finding the copy protection and diverting it. The most clever protection was in Pac Man. It wrote to memory with relative addressing which means it could work right some times but write to ROM memory other times. So I just diverted it to my own subroutine that detected where it would write and NOT write if it was ROM space. Guess who wrote that copy protection? Marc Benioff.

[@powerofvintage9442]

The Atari 8-bit Pacman is my favorite of the bunch.

[@mmille10]

Marc Benioff wrote some graphical Ultima-like adventure games for the Atari. I've seen videos of a few of them.

[@FXGreggan.]

Ahh the 800 was my first computer, really fond memories :)

[@powerofvintage9442]

Not my first computer, but first computer experiences.

[@AutomationDnD]

Me too

[@neilloughran4437]

This takes me back. 1982 and the first ever computer shop opens in my home town... I remember seeing this and the 400 with the cart doors open and Star Raiders. Also there was a Dragon 32 and some ZXs. While I got a C64 the following year I always heard the Atari 800 was far superior in many respects (more colours, faster also I believe) ... I believe the game "Blue Max" was quite a standout for its time.

[@powerofvintage9442]

Both the Atari 800 (8-bit architecture) and C64 are awesome computers each with their own advantages and disadvantages.

[@AutomationDnD]

I was in college, in a double-degree program for Physics & Elect Engineering in '87 to 92 one of my Best Buddys in college had this Atari 800, he was a Software wiz I remember many a weekend of Vodka-fueled _"Star Raiders"_ sessions with Jim Weinstein

[@GerardPinzone]

Something I didn't know was that while the Atari did output both chroma and luma like S-Video, the peak-to-peak voltage was 1.0v like composite, but the S-Video standard is (I think) 0.7v. If you want to build a cable, you probably will need a resistor to lower the voltage slightly.

[@bigbadhodad3894]

Scoutmaster had an 800, and that computer was one of the first I really got to use, we used it for out computer merit badge (the original version that was super hard, you had to do flowcharts and create basic programs, not just show you could log into fail book)

[@powerofvintage9442]

Awesome! The harder the merit badge requirements, the more you remember and learn.

[@user-Atamigaputer]

Wow, in an Atari collector these days but started off with the Atari 800. It seems like you we had a fantastic time playing M.U.L.E And who can forget Behind Jagi Lines. I still enjoy both the 8 bit and 16 bit machines and like to play with original hardware

[@powerofvintage9442]

My computing journey started with the 800 / 800xl. Great systems and still fun to work on and play.

[@TheAtariCreep]

I have had an 800 for a few years now and didn't really know much about it aside from playing games on it. Appreciate this video, man.

[@powerofvintage9442]

Thanks!

[@bitcortex1991]

My favorite computer model of all time. As I understand it, Atari designed the hardware to be a successor to the 2600 game console - the 5200 - but (a) the 2600 was selling like hotcakes long past its forecast expiration date, and (b) home computers were taking off. So, Atari postponed the 5200 release and, in the meantime, released the 5200 hardware with keyboards and more RAM as the 400/800. The graphics and sound chips made the 400/800 easily the most powerful home computers of the day. By designing a new game console, Atari accidentally raised the bar for home computers 😊

[@unebonnevie]

The Atari 800 is very well made. I collected all Atari 8-bit computers, including the somewhat rare Atari 600XL.

[@powerofvintage9442]

I love these computers! I have all of the publically released 8-bits as well (kind of like Pokemon). Although, I don't have a 65xe since it's basically the same as the 130xe just without the RAM.

[@PM-xc8oo]

This thing is seriously impressive for 1970s tech. Hard to believe that it was still kicking around in the 1990s considering how fast tech was developing during that time.

[@powerofvintage9442]

That's exactly what I was thinking. I mean the Commodore 64 was impressive too, but the Atari 800 came 3 years earlier.

[@user-Atamigaputer]

love discovering your channel, have subscribed. Ive got all the flashjazcat stuff, lotharek stuff and the fujinet cart plus UAV and untimate 1meg, it all just adds to the fun

[@powerofvintage9442]

Flashjazzcat truly is the master of the Atari 8-bits. Love his channel and work!

[@Jammet]

Can't wait for the mini version of "this", it's a 400 visually though.

[@dannymatthews855]

Excellent video. thank you.

[@powerofvintage9442]

Thank you!

[@CaribouDataScience]

I had one of those I also had atari writer (word processer) and ViciCalc for it. Oh, and of course Star Raider

[@powerofvintage9442]

Great software! Both productive and fun.

[@desiv1170]

I do love the 70s feel of the early Atari 8-bit machines... I think a bit more so with the Atari 400, but both the 400 and 800, you can really feel the 70's computer era still... I wanted one back in the day, but money wise, my family could afford the Vic-20, which I did still (and still do) love... But yeah, either would have been nicer (Atari 400 keyboard of course being the issue there... ). I do now have an Atari 400 and love that machine. (Expanded to 48K and have a Fujinet) I do think the Atari 8-bit line competes fairly well with the C64, which is impressive considering how much earlier they were developed... Jay Miner and his team were awesome!!! The tricky part about a comparison of the Atari 8-bit line to the C64 will be the C128... If you are including the later Atari 8-bit machines, do you also include the C128? It's a big jump, but also there's a lot of C64 in the C128 (literally ;-).

[@powerofvintage9442]

I would compare actual software and actual performance. I have a lovely C128 but there isn't too much software that really pushes it. I'd compare the C128 vs the 130xe...not much took advantage of the 128kb on the 130xe either. The biggest advantages in my opinion is that the C64 became the common denominator and had just a little more RAM than the A800 which became in some ways the common denominator for the Atari 8-bits.

[@Richard.Linder]

I had an Atari VCS, then a Commodore 64, and then Amiga 500 and 1200, before finally moving to PC. I knew about the Atari ST range, but I don't think I was even aware of the Atari 8 bit range of computers until I saw it in Retro Gamer, decades later. I've tried emulators, some of which are very good. And Gamebase has a great collection, with screenshots and additional info. There are some great Atari websites, with fantastic resources, backed up by a great community. I never really subscribed to the us vs them mentality. Sure, I had Commodore computers, but if there was other cool stuff out there, I would love to have experienced it. I've been fascinated by the Atari 8 bit computers ever since I discovered they existed. I'd really like to see, hear and touch the physical machines in real life. They seem so cool - way ahead of their time, with a solid build quality, especially the early 800. But really, I'd want to see them all, including the XL and XE range. I feel like an important part of early computer history just passed me by. And the loading speed, compared to the Commodore machines, is enough to make me jealous! 🙂

[@powerofvintage9442]

Both Commodore and Atari 8-bit systems are really awesome and were so amazingly capable versus what else was available at the time.

[@gamedoutgamer]

Great video! Enjoyed it. Well done video that is clearly explained. You don't have to use external USB power for your fujinet on the 800. Just power it on holding down START, then press RESET after a second or two. 24:45 your TV here almost certainly has a low quality composite interpolator. Another LCD display could give you much better quality. The early-era LCD's displays (with composite + svideo) often have a better composite experience. This was to better facilitate the transition from analog video devices, including DVD players and game consoles, etc. I do not recommend installing a UAV video enhancement into an 800. They have the best output of all Atari 8bits, followed by the XE's. 800XL's have the worst, by far. The 1200XL has a unique chroma saturation circuit which is nice but I end up installing a UAV into them, if needed. 0:30 The 400/800's were publicly demo'd in March '79 but due to production delays, not available until November in only very limited quantities. Spring of 1980 saw better availability but the high initial cost inhibited sales. Star Raiders was the 'killer app.' The platform saw hardware developments in peripherals and new models into the late 80's. =) 6:32 there was a similarly brown IBM typewriter (but taller) that looks close to the 800 design. Yes this was intentional as you say, for familiarity with consumers. 8:00 Your motherboard looks like it was not installed fully into the joystick holes in the case and this causes a lot of pressure on the joystick ports to the motherboard. It's easy to mis-install the motherboard this way. 8:54 late model 800's didn't have the rf shield on the cart door as a cost reduction from the factory. Yours has screws instead of levers because the RAM came fully upgraded. 10:19 your side panel looks pristine. This 800 wasn't used much judging by appearance! 21:30 there are two variations of the 800 CPU board. One has a true 6502 with four support chips (yours has these). The other CPU board uses the custom Sally variant with CPU halt line to save cost on the support chips. As you said here in comments, the 800 case is brittle with age and with the heavy internal aluminum faraday cage they often shatter in shipping due to poor package padding, very sadly. They are built very well otherwise. The XL's are the sturdiest for shipping in the mail, followed by XE's then the 400 and lastly the 800. The 810's are also very commonly crack and shatter in shipping. 7:24 Mostly agree with the original 800 keyboard being a little tiring to use due to it's height and stepping. It is very good though. The Back to the Future script was typed on it! =) The uncommon ALPS variant keyboard on the 800XL is super fast and easy to type on. Most 800XL's have the SCCO stackpole keyboard which isn't very good (bigger keys bind when pressing corners and all keys have rough texture). The 1200XL has a very nice Mitsumi keyboard and some 800's have a nearly identical Mitsumi which are great but the mylar needs servicing. Your 800 keyboard variant is a HI-TEK, seen at 18:17, which is the original keyboard for the 800. Avoid uncommon 800's with yellow plungers under the keycaps (Stackpole keyboard). They have cracked with age and no longer hold the keycaps. 21:12 indeed it's like the Pentium II boards! 23:00 Mild cringe here from powering on the disk drive with the disk in it. It's taboo because early 810's did not have a protection circuit and would damage the data on the disk when doing this. Your drive is a late era Tandon 'revision C' drive which does not do this, but us Atarians had it drilled in our heads (from magazines and game manuals, etc) to never turn on the drive with the disk inserted. Only revision A 810's did this and they seem very rare. The Atari 8bit FAQ covers this fault in the 810 drives section. 28:28 I do NOT recommend installing Incognito into an 800 because the install damages (ie. permanantly alters) the computer. Some say that the install can be done 'cleanly' without cutting traces and plastics but I don't see how. Much easier to just get an XL or XE machine for that compatibility. I take some offense to treating these very nice antiques as a modding hacking platform. Just because something can be done doesn't mean it should. For an 800XL, the UAV or U1MB instlall is fully reversable. An 800XL isn't nearly as 'special' as an 800. They only made about 530,000 800's. Most are gone, thrown away. A lot more 800XL's were made and are very common on ebay. There is a lot of present day misinformation from users of other platforms. Here though, your information is very good. Most often see C64 users state false information has hard fact. Many differences between these and the C64. Some disadvantages and, imo, many advantages. The PIA chip for the joystick ports for example allowed hard drives (Corvis HDD) and modems to function. I'm doubting a C64 could do that but unsure. Amiga and ST mice both work no problem. The build quality and reliability is far better, including the chips. Much better DOS system from the start. Supports a wider range of RAM configurations, including RAM disk feature. A whole book could easily be written on the many differences. When SID chip is used skilfully by software, it's awesome. Love the 16 color text mode on C64. 800 can do multicolored text but not like that. Only color registers, not RAM, on A8 series. C64 has better sprite capability ofc. Late 80's saw far more software on C64. Most native A8 software is better to run on the A8 and usually performs better. Compare the framerate of Eidolon, Fractalus or Fort Apocolypse between them, or the resolution of Ballblazer. Blue Max is much better on A8, specifically the sound effects and color. Far more cartridges on A8 and the cart quality is top tier with the spring loaded dust covers and metal/plastic hybrid consturction. Shops started telling people to get a C64 instead of A8's in '84 due to Atari collapsing from the 2600 crash. Had nothing to do directly with the platform. Cheers and thanks for the vid! ps I did a tutorial vid on A8's in my channel. One of the newest vids.

[@powerofvintage9442]

Thanks a ton for the information. I love my 800 and, no I haven't installed a U1MB or Incognito in mine, in large part because as you mentioned, I have my 800xl for that (which I do find very useful).

[@MrSpacelyy]

Cool video, subscribed

[@powerofvintage9442]

Thank you!

[@sideburn]

I had an 800xl. Then 130xe. And I got a Happy 1050 for my floppy drive and pirated all kinds of games from that point. I wrote a BASIC program to hack out ATT calling card codes so I could download the latest games from Europe BBS’s before they were available in USA. It was fun to be a 15 year old criminal in the 80’s 😂 * The floppy drives were computers themselves with their own 6502 in them.

[@dempseydiscus]

C64 vs Atari 800 comparison - yes please :-) also, it has always puzzled me, why Atari continued launching machines based on the same technology as the Atari 400/800, don't get me wrong, I love the Atari 8bit line of computers, especially the 800 which is my favorite Atari computer, but using that technology again in the Atari 5200 (and then NOT making it backwards compatible?! in the words of AVGN - "What were they THINKING" ;-)) then they continue using it in the Atari XL line of computers and yet again with the XEGS in 1987 - were any of those machines big successes - NO, then why didn't they invent something new - the first new thing they did was the Atari ST computer. The Atari 800 however, when it came out - in my mind - blew the competition away - none of the competitors at the time of launch had anything that could compete with the 800!

[@powerofvintage9442]

Will add it to a video topic to cover.

[@madigorfkgoogle9349]

well, it is a simple answer, it was selling. It isnt true that the 800 line of Atari was not selling, even in the end of 80s and begin of 90s, this was still a great cost effective "toy" computer which could made your kid to a good material for emerging industry you as a parent didnt understand a thing. Same is true for C64. The games were still OK-ish, remember all those VCS clones from China still sold on mass until early 2000s. And actually Atari ST was same success as 800 and blew the competition away. Non of the computers on market in 1985 gave you same abilities, comfort o use, power for so little money. Same is true with Falcon, there was not even remotely close computer that gave you so much for such low price. And to be honest dont forget the TT030, when it came out, it was the fastest 68030 computer on market with excellent hi-rez monochrome graphics and a lot of features in compact workstation design. The PC world surpassed TT very fast with 486 and 486DX2. Also worth mentioning is the Portfolio and Lynx as a milestone portable devices. And I will close up with a cool idea that became a failure at the end, Atari Transputer... Damn, I have one more coole design that failed (or never came into mass production) but was "copied" by Apple and become groundbreaking in computer history. The Atari ST Pad, damn apple even copied the name...

[@mmille10]

This also frustrated some of Atari's engineers. It's why they left the company to start their own, like Activision, and Amiga. Atari was doing research projects in the early 80s with technology that was years ahead of its time, but they developed hardly any of it into products. The only research projects that made it into commercial products were the 400 and 800, in 1979, and I think AtariLab in 1983. Once the 400 and 800 were released, Atari didn't think to use its research for new products, even though they were funding it. It seemed like Atari used its research funding only as a tax write-off. The way one former Atari engineer put it was that Warner Communications, which owned Atari from 1977 to 1984, was an entertainment company. They thought of Atari like a blockbuster movie. The way the entertainment industry works is they release a movie. They don't improve on it while it's popular. They just market the hell out of it, until the public has its fill of it, and then they throw it away, and try to find the next popular movie to make. That's what they did with Atari. Its home and arcade video game business was making hundreds of millions of dollars; a healthy business, and then market saturation bit it hard in the ass. Their consumer products ran out of customers, because they didn't think to come out with any new, exciting follow-ups. Their home video game business went into free-fall in 1983, an epic collapse, and so they liquidated parts of the company, and spun off other parts. The consumer division, which made the VCS, and Atari 400/800/XL computers, was sold to Jack Tramiel, the former head of Commodore, in 1984, and he kept that business going for another 12 years, until he sold it to a disk drive manufacturer. The XE and ST computers were released a year after Tramiel took over.

[@c128stuff]

This thing is built like a tank, and quite over-engineered.. but also really nice.

[@powerofvintage9442]

The interior is a tank, but the plastic is getting a little brittle over time. One of my 400's has a shattered casing....the cast aluminum is still rock solid :)

[@ecdhe]

The FCC really screwed Atari on this one. Their requirements that computers had to block any potential electromagnetic interference led Atari to design the 400/800 like tanks, driving costs up (wonder why the previous computers were not affected). And 6 months after those were released, the FCC relaxed its rule.

[@powerofvintage9442]

Kind of crazy.

[@ecdhe]

@@powerofvintage9442 yes, because it was critical that, should someone decide to use their Atari 800 in a plane during takeoff, the computer would not interfere with the electronics of the plane ;-)

[@whiplash_pants]

My dad brought one home when I was 5 I can remember Bruce Lee and Big Bucks. God this brings back memories...

[@plechaim]

I would be very interested to see a battle of the 8-bits video Atari vs Commodore, I have only owned Commodore, Amstrad and Sinclair 8-bits so would be interested to see how the Atari 800/XE stacks up to the Commodore 64 in particular

[@powerofvintage9442]

Both are really excellent computers. Each with their own advantages.

[@sideburn]

We Atari kids called the commodores “Commode Doors” back then 😝

[@WinrichNaujoks]

So Brian and Bryan must have been the rich kids.

[@powerofvintage9442]

lol

[@clutch2827]

I still have a large crt tv that I saved for this reason but the picture is totally messed up now. I'm assuming from not being used for years.

[@powerofvintage9442]

what's the issue with the TV picture?

[@clutch2827]

@@powerofvintage9442 just weird pinkish messed up kind of can't make out anything. I'll dig it out again one of these days. Problem is not too many people around that fix these. I went through monitor hell with my arcade machine monitor.

[@DaveVelociraptor]

I've never seen an 800 stripped down. I know in your head to head you gave the Atari points for being so well built, the XL range certainly is but the 800 looks excessive. However it's a 70s design, and nobody really knew where things were going so I can understand it.

[@powerofvintage9442]

After looking at some typewriters from that era, it's clear the design inspiration came from typewriters.

[@TheHighlander71]

The boot process and disk handling of the Atari 8 bits always confuses me. The 800 doesn't have a disk operating system, but when you plug in a disk drive with a disk in it, it will just boot from disk. I have an 800XL with an Atari Max cartridge and the options on it are like dark magic to me. Interesting video this. I wouldn't mind learning a little more about my 800XL.

[@powerofvintage9442]

The 800xl, generally needs the Basic in ROM disabled to boot from much of anything else. That means holding down the option key. Cartridges though bypass that I believe. I’ll definitely get to a deep dive on the 800xl!

[@madigorfkgoogle9349]

the disk operating system is "built in" in the floppy drive, the drive basically has the same CPU board then the 800, sans the graphics chips, so it is a full fledged microcomputer communicating with 800 via SIO serial bus.

[@TheHighlander71]

@@powerofvintage9442 I would definitely watch that. I don't know if you're familiar with the Atari Max cartridge but the options in that thing break my brain :)

[@TheHighlander71]

@@madigorfkgoogle9349 Thanks. The same goes for the 1541 and the C64. But the Atari 8 bits must somehow already be able to pass control to the disk drive when they detect it.

[@mmille10]

The SIO bus responds to some commands (not text, but in terms of sending/receiving bytes). The disk drives had a CPU on board, and a little bit of RAM and ROM, but no built-in DOS like the Commodore 1541. The way it works, as I understand, is the computer tells the disk drive what tracks to send back, specifically a boot track, which locates DOS.SYS. It tells the drive to send this located file over SIO, which the computer loads into memory. This is the disk subsystem the computer uses. Once that's loaded, the computer's OS turns control over to DOS's boot process, which looks for a file on disk called AUTORUN.SYS, which is an optional auto-boot program that can be loaded, as well. You'll find many boot disks use AUTORUN.SYS. A typical boot disk also contains DUP.SYS, which is the Disk Utility Package. That's what you get to when you type "DOS" from Basic. Another file that's typically on such a disk is MEM.SAV, which is actually a swap file (I didn't understand this until years later). When you "go to DOS" (DUP.SYS), it needs some memory that Basic uses for program memory. So, before the DOS subsystem loads DUP.SYS, it saves a portion of Basic program memory to MEM.SAV on disk, and then loads DUP.SYS. If you haven't done something like copy a file (which needs more memory), and you want to Run Cartridge (return to Basic), DOS will automatically reload the memory saved in MEM.SAV before returning to Basic. This way, you get your Basic program back. :) The reason that doing something like copying a file erases your program memory is DUP needs that memory to do the file copy, and the amount is more than what's saved to MEM.SAV. This is why it warns you, "this will invalidated MEM.SAV." It seemed like Atari did a compromise with this design, because they could've made MEM.SAV bigger, to save your entire program memory, but that would've taken up more disk space, and it would've taken longer to save/load. People would've wanted to use that space to save programs and data files. Disk space was already limited (80K with 810 disk drives), so they made it a size that would work in most circumstances.

[@massmike11]

The atari disk drives were certainly better than the commodere ones

[@powerofvintage9442]

They definitely load tremendously faster.

[@johneygd]

The atari 800 is definitely a great system but is it also indeed wider then the atari 400??? By the way i never knew that ultima 4 did took advantage of composite artifacts just to create color,that’s just mind blowing so you will get 3 for the price of just 1😁

[@powerofvintage9442]

Yes it is wider than the 400. Just comparing the two right here.

[@ScoopDogg]

UK here BBC model B hold my beer : ) and has anyone heard of the game Elite outside the UK , hell of a proud moment for us in technology then, shame it went down hill from then Me in xmas 1980's "mum can i have an Atari 800 computer for education purposes" DAD "no we cant afford one son" .......2 years later....... Me "can i have a computer mum they are used in schools called the BBC micro for education to learn programming" Mum "no, maybe next year when my widows pension goes up and you dont need one, whats wrong with your atari 2600 you got in 1977" Me"WTF! MUM I miss my dad" My Stepdad "Oh why not , it is for his education Mary and he has lost his dad" Me "Happy ffing days" : ) And that my friends was the only good thing that came from me losing my dad in the falklands war, i got a bbc model B 32k : ) it was hard growing up in the 80s in a yorkshire mining town. WISH I HAD NEVER SOLD IT TO GET AN AMIGA and kept it now : (

[@powerofvintage9442]

So sorry to hear about your Dad. The BBC micro is an amazing computer of the likes of the Atari 800 from what I've seen. Fantastic build quality and expandability.

[@massmike11]

The sdrive max can emulate four floppy drives and a casste

[@powerofvintage9442]

Yes and it has a nice boot interface as well to select the images from the SD card. It's a great device and was my go-to until the fujinet.

[@chloedevereaux1801]

those 2 screws don't hold the ram cover on.... they hold the metal case to the bottom case.

[@powerofvintage9442]

You can't remove the RAM cover without removing those two screws (and washers). Other versions (the two others I have worked on previously) of the 800 have latches mounted in those locations that need to be moved before removing the ROM/RAM cover. The metal case screws are located on the bottom of the computer. Perhaps there are different versions?

[@RBLevin]

If not for Atari, Apple wouldn't exist.

[@mmille10]

Hmm. There is a relationship between the two, but I dunno. It wasn't like Atari launched Apple, or that something there inspired Jobs and Woz to start the company. Really what started Apple was Woz working on his own homebrew computer, which became the Apple I. Though, I have heard that some Atari engineers "liberated" some parts Atari had, giving them to Jobs and Woz, so they could make their first shipments of Apple I's. Maybe that's what you're referring to. Another connection was that when Jobs and Woz worked on Breakout at Atari, Jobs used most of the money they got from that to take a trip up to an orchard in OR. The lore is that Jobs got the idea to call the company "Apple" because of a suggestion from someone at that orchard.