How Oldschool ROM Cartridge Games Worked

How Oldschool ROM Cartridge Games Worked

Hello, and welcome to another episode of the
8-Bit Guy. In previous episodes we have discussed floppy
disks and tape games. And today, we’re going to talk about cartridge
games! The very first games were distributed on cartridge
format for the Fairchild Channel-F, and soon after on the Atari 2600. ROM cartridges were used in all kinds of systems,
such as the Speak and Spell, musical keyboards, and even game systems as new as the Nintendo
64. I have also invited the Obsolete Geek to come
over and show you some of his collection. [OG] So, I am a huge fan of cartridges and cartridge
based systems. Couple of my favorites, obviously the Neo
Geo, an arcade based platform, which has absolutely massive cartridges. Which could be a little tricky to plug in. Also, another one of my favorites, the turboGrafx,
also known as the PC Engine in Japan, which has these really cool credit card-shaped cartridges. Also very unique. [8BG] As a kid with my Commodore VIC-20, I was obsessed with trying to copy a game cartridge to tape. You see, I believed that the game was somehow
loaded into the computer’s memory much like a game would be from disk. And I had noticed that if I pulled out the
cartridge game while the computer was on, most of the time it would lock up. [buzzing] I noticed that every now and then when I’d
pull the cartridge out, the computer would return to a READY prompt. And so then I would attempt to save the game
to a tape. Of course, it never worked. And the main reason it didn’t work is due
to my complete mis-understanding of how these games worked. So the 6502 processor could only access 64k
of memory. So, for these examples I’m going to be talking
mostly about the Commodore VIC-20, because it has a simple memory map that’s really
easy to understand. So you might imagine the memory map looking
something like this. Keep in mind there are two types of computer
memory: RAM known as Random Access Memory, and of course, ROM, known as Read Only Memory. So, the VIC-20 only had 5K of RAM, and thus
the memory map looked more similar to this. So the Kernel and BASIC ROM were at the top
of the memory map and the 5K RAM was at the bottom. There was a lot of empty space where if the
processor tried to read and write to that area, there was simply nothing there. So when you insert a cartridge, it literally
adds this additional memory into the main memory map of the computer, adding to the
total amount of memory in the system. In this case an 8K game cartridge is adding
read-only-memory, but you can also add an 8K memory expansion cartridge which will add
RAM to the machine instead. Some cartridges even had 16K of ROM or RAM. But once the cartridge is removed, the information
is no longer visible to the CPU, hence why I was never able to save those pesky game
cartridges to a tape or disk as a kid. Now on a modern computer, most of us are familiar
with what it looks like to add some RAM expansion. But, aside from the BIOS chip, modern computers
really don’t have any ROM chips or ROM sockets, because they pretty much expect all software
to be loaded from either disk or USB or something like that. So even though the VIC-20 has 5K of RAM,
it really can only use about 3.5K because the rest of that memory is used for screen
memory and some other kernel functions. So if you load a game from tape or disk, the
maximum size of that game will be limited to about 3.5K. And these sort of games loaded
into the VIC were usually extremely primitive games. But a cartridge game can be as much as 16K. And so the games can be considerably more
complex, with more graphics, etc. So in the case of the VIC-20, cartridge games
were usually better. [Ms. Pacman music playing] So that’s the Commodore VIC 20, but a few
years later the Commodore 64 came out with 64K of RAM and this changed things up a bit. You see, a cartridge in the C64 is still limited
to 16K. And the games that were on these cartridges
weren’t neccessarily bad, but they were limited mostly to the classic type arcade games. But when you load a game from disk, suddenly
you can use almost all of the machine’s 64K which means the games become even more rich
and complex. The original Atari computers tell a similar
story. The 400 and 800 both shipped with 8K of RAM,
so the vast majority of games were released on cartridge. These systems were designed with the slot on
top much like a game console, which suggests they expected most games would be on cartridge. So interestingly enough, the Atari 800 actually
has two cartridge slots, one of them is labeled left cartridge and the other is labeled right
cartridge. Now, all of the cartridges I have are are
actually- they say “left cartridge” right on the ROM cartridge. Now, I don’t think that the right cartridge
was ever really used for much, in fact they got rid of it on all of the later models of
Atari. But, I think the idea was, back at this time
the machines had 16K of RAM and so I think they were thinking that you could load like
a primary cartridge in one socket and the other socket could be used as some kind of
addition. Let’s say for example you had some kind
of music or art program or something, you could put it in here, and then if you had
actual pieces of music or artwork or something, it might be on a secondary cartridge that
would go along with that. Maybe. I’m not entirely sure what they were thinking. Most all of the early classic games are available
on cartridge, but by the time the later systems came out
with 64K, most all software was being distributed on floppy disk, however the cartridge slot
was still prominently displayed on top of the machine, except for the 130XE which was
more similar to a Commodore. Interestingly enough, Atari took one last
shot at cartridges with the release of the XE game system, which was fully compatible
with all previous Atari computers, but seemed to emphasize the game console aspect since
it could be used with or without the keyboard attached, and the games were expected to be
loaded by cartridge. However, very few new games were released
for it on cartridge. So, it was technically possible to put more
than 16K in a game cartridge for these systems. But since the memory window given to these
cartridges was only 16k wide, the only way to accomplish that was to add additional hardware
into the cartridge that would allow bank switching so that only 16K is visible to the computer,
and the game software can switch around which sections need to be used at different parts
during the game. Many Nintendo cartridges did this, with many
games including as much as 1 MB of ROM, which was a substantial amount of data for the time. However, this technique was rarely used on
cartridges for computer systems, because ultimately, it was just cheaper to put the software on
a floppy disk. Another interesting note is that not all computer
systems even had ROM sockets. For example, the Apple II series never included
games on ROM cartridges. Although technically speaking it has the equivalent
of 8 ROM sockets inside, which were used for expansion. Technically you could have designed a game
to work in one of these, but in practice it was never done. The same can be said for the IBM PC, although
the PC-Junior did have cartridge sockets. So a common thing to see back in the 1980s
was someone blowing inside of a Nintendo ROM cartridge. Now, honestly, I’ve never actually seen
that that does any good unless there’s visible like dust bunnies or hair or something in
there that you’re trying to blow out. For the most part, It’s just corroded contacts. I think it’s more of a placebo effect to
blow into it. I think what’s really helping is just the
removal of the cartridge and putting it back in, which is helping to scrape a little bit
of the corrosion off of the copper contacts. But honestly, once a game gets old you really
need to give the contacts a proper cleaning. The internet is full of solutions to this,
but my preferred solution is to let the contacts sit in vinegar for a few hours to eat away
the corrosion. However, sometimes I’ve had luck using baking
soda since it acts like an abrasive. So, cartridge games were a lot more difficult
to pirate, but on the bright side at least there wasn’t all that much need to make
backup copies, because these darned things were practically indestructible. So, cartridges have two advantages over other
types of media such as floppy disk or even CDROM. The first is, of course, they’re instant
on. There’s no wait time in order to load the
information. But the second thing, and this is
something a lot of people don’t realize is that cartridges can contain other things
besides just information. They can actually contain extra hardware to
make the console more capable. I’m going to let The Obsolete Geek explain
it further. [OG] Pitfall II, which was released on the Atari
2600 was revolutionary for the console. The game play was considerably more complex
than other games, as well as it included a sound track that played throughout the game,
a first for the platform. It achieved this by adding a specialized chip
known as a DSP chip inside of the game cartridge that gave the system more capabilities than
the Atari 2600 was ever designed to do. This practice was also used in other systems. The Nintendo, for example, contains 2 KB of
onboard RAM, but a game cartridge may contain additional RAM to increase this amount if
needed. This is the Japanese version of the Nintendo
Entertainment System, also known as the Famicom in Japan. While the electrical components are very similar
to the NES, and the cartridges in Japan are a little bit smaller, there was one key difference
that some games such as Castlevania 3 had. In which case, this game has an additional
sound chip which adds a couple of extra voices to the NES’s original sound chip. You can clearly hear the differences between
the two. In fact, while the cartridges might be shaped
differently, you can buy an adapter, which will allow you to plug this into an NES, although
because of the way the console is wired, you will not get the additional sound without
a couple of easy modifications. The Super Nintendo was actually designed to
take advantage of additional hardware in the cartridges as needed. So, let’s take a look at these two games,
for example. Stunt Race FX contains a co-processor called
the Super FX, which assists the SNES with 3D polygon rendering. Have you ever played the original StarFox? It also uses the Super FX chip. Super Mario RPG used a chip called the SA-1,
which actually contains a CPU core similar to the one that’s in the Super Nintendo
but is operating at a much faster speed. Hardware addons were very common in Super
Nintendo games. So the Atari 7800 was considerably more advanced
than the 2600, but they kept the same primitive 2-voice sound hardware from the 2600. However, some games actually added the POKEY
sound chip from the Atari computer line into the actual game cartridges. This is one example, Ballblazer. You can hear that it actually has a far more
sophisticated soundtrack than most 7800 games. [8BG] So, one interesting thing about cartridges
is that each manufacturer had their own design or particular appearance to their cartridges. All that mattered is that it could fit into
the machine, but they were free to shape the rest of it however they wanted. So, take a look at all of these cartridges
for the Atari 8-bit computer line. All of the Atari branded ones have this same
design. Admittedly, I sort of like the appearance
and especially the metal plate covering the back and top. But Activision, for example, used an entirely
different shape to their cartridges on the same platform. However, the story is not always the same
from one platform to the next. For example, all Nintendo cartridges look
more or less exactly the same, no matter what company made them. Well guys, I hope you enjoyed this and I’ll
see you next time!


  1. relatively soon after the release of the VIC-20, third party "40K RAM" modules were available for the machine. They contained 32K of RAM for the standard BASIC extension within the lower memory map region of the VIC-20 (like the official Commodore 32K RAM modules did) and 8K RAM within in the upper "A000" (hexadecimal) ROM module reserved memory map region. Game modules that had been binary copied to a compact cassette were reached out in computer clubs and loaded into that region of the 40K RAM expansion by setting the BASIC load pointer to hex. A000 before starting "LOAD". Then a documented (or just guessed) "SYS" call to hex A000 (or a few bytes later to skip the first Assembler command of the ROM game) was typed in and the game started.

  2. I can't believe how expensive that pitfall 2 cart is.

    But the blowing into the carts wasn't a placebo effect. when you blew into the cart it was the moisture from your breath that would improve the contact from the cart to the system, and often the game would start playing again. Had quite a few games that would not work unless you blew into them. But in the long run this was far worse for the cart as the moisture from your breath would further corrode the pins.

  3. You actually enhance and augment my childhood. You fill in the blanks I had as a child and that enhances my memories of my time with the Atari 2600, C64, NES and so on.

  4. Ok , with cartridge instead CD's or disk media it's possible to add extra hardware chips add on better capabilities . This work with all cartridge based hardware?? For example , one Game console use a CPU with 12 Mhz , but the company released a new chip version running at 21 Mhz . Will be possible to add this chip speed advantages with add on a cartridge?

  5. This is the hardest thing to convince people on, the cartridges were a circuit board meaning the creativity of what goes on that circuit board is almost unlimited, it's limit is only that of the budget and the creativity of the developers. People seem to only think of cartridges as a dump of rom code, I've even had people argue with me on this, "a cartridge is just a dump of rom code on a chip" but it could be so much more and many companies took advantage of that when releasing certain games.

  6. Cartridges may not store as much as an optical disk, but at least they are physically stronger and can have extra hardware, so that's cool.

  7. Examples of Atari 2600 super cartridges include the Starpath Supercharger, and Mattel's M Network releases of Burgertime and He-Man.

  8. I just played a real Donkey Kong Arcade game at the Rochester, NY Airport. The had a small vintage arcade set up. Best of all, all the games were FREE! That was great as my flight was delayed!!! Boy that bought back memories. Come back 80s, all is forgiven!

  9. In the whole video he does not even mention how old skool cartridges worked…. nothing about how the darn cartridges work…..

  10. I loved cartridges because shops wouldn't do refunds if you had played games so I used tinfoil to short them out so they had to give me a refund because it was faulty.

  11. Back in the late 80s and very early 90s, i always wondered why many cool electronics were released in Japan but not in North America.
    It didn't make any sense.
    Every now and then I'd hear of amazing stuff that was only available in Japan.
    It was like some mythical land of gizmo heaven.

  12. 8:28 – The Apple II in fact had several ROM-sockets (i.e standard 24/28-pin DIL-sockets on the pcb). You seem to use the term "ROM-sockets" for cartridge slots as well as for general bus-expansion slots, but not for actual ROM-sockets.

  13. my cartridges are sooo old and corroded that half of thosw copper pins are no longer there. they worn out as if it was wall paint. Thankfully I can still play all this in today's computer.

  14. does anyone else remember The Freeze Machine Cartridge for the C64? allowed me to save tape games to a 5/4 floopy disk….could also access the code to poke and peek at the data to give your self some extra lives…yes it was cheating…it also did screenshots so you could pause maze games etc……maybe the freeze machine could be something featured in the future?……..

  15. We rigged up an Atari so that we had 8 joysticks so 8 of us could play. Each person could do one thing, left, right, up or down, buttons.
    We played Ball Blaster that way and it was nuts. Yelling at each other to go left or forward.
    Then we played the original Castle Wolfenstein with 5 people, which was a riot, trying to get the passes out quick enough or when to pull the knife to backstab

  16. We used to copy all of our cartridges on CoCo. One reason we did this was that the hard drive controller occupied the cartridge slot. Yes, the expansion cartridge bay thingy existed, but if you can just copy a cartridge, you copy the cartridge.

  17. The cartridge blowing isn't a placebo, it ALWAYS works. I tried just taking it in and out as a kid and only blowing on it always worked.

  18. I wish cartridges were still a thing. Alle the possibilities (you already mentioned extra hardware) are just awesome. Extra RAM, more power, additional processing units, etc. Plus: Giant storage capacity. Just imagine a NES cartridge with nowadays technology in it.

  19. C64 version of Pitfall II only had standard sound but I think the amazing thing was how they fit such a detailed game into an 8K ROM. Kudos to the programmers

  20. 3:06 Now modern Computers have flashable ROM for a Manageability Engine, like Intel Management Engine (IME) or AMD Secure Technology (AST).

  21. THE BLOWING METHOD WORKS. I got out my dsi and tried to play pokemon pearl. I reinserted it 3 times nothing. next i blew into the card slot on the dsi and bam! it worked.

  22. What I have to do in order for see videos in its original language? This video tittle and description appears me in spanish, but what if at the same time I want to see other videos in its original language like spanish. I want to be able to disable the option to translate subtitles automatically because it is very confusing and annoying.

  23. Oohhhh, at 12:49, that's my country…
    I did not know how that chip was made at the Philippines…😅😅😅

    Labas na mga pinoy…

  24. I own about 30 NES and SNES cardriges along with the corresponding console. All of them are work wonders, even after ~20 years of my family passing them to the next generations.
    Nowadays, computers and consoles last only for 1 year and then something breaks…

  25. Licensed NES cartridges all looked the same because Nintendo wouldn't let other companies manufacture them – they made the carts themselves, and shipped them in limited quantity to companies that ordered them. This was done to keep them from flooding the market with crappy games, which is what killed Atari in 1983. This is why some bigger game companies made games under multiple brand names (i.e. Konami and Ultra) – to get around the order size limitation and make more money selling more games by pretending to be separate companies.

  26. The blowing is not a placebo effect. When there is lack of humidity and the air is so dry, this tends to create electrostatic charges, specially near some plastics, so when people blowed air into the cartridge they were providing humidity for the electrostatic charge to dissapear… at least for a while.

  27. One thing that missing about the NES was the fact that the NES hardware was very limited with initial cartridges only having 16Kb size. Hiroshi Yamauchi wanted to keep the cost of the console relatively low so it would get to more homes as fast as possible. If the added MMC chips (which first came out in 1986) inside the cartridges didnt exist, the Famicom would have been obsolete by 1987. I wouldnt be surprised if Nintendo's R&D3 division (they designed the cartridges) got ideas from the Pitfall II cartridge on how to expand the hardware capabilities of the console.

  28. Cartridges… I remember when I found out how to copy Action Replay. Not just the EXROM stuff under 8000 but the stuff under I/O at DE00. I felt so clever!

  29. The blowing on cartridge connectors helps by adding moisture on the contacts assuring a better connection through the conductivity of the moisture. Literally instead of blowing, try spitting. It isn't good for the connectors though since the moisture overtime created even more corrosion.

  30. Bar Keepers Friend (the original powder form) is the perfect cleaner for edge connector contacts. Being a powder (that you mix with water), it's a very mild abrasive like baking soda is, but it also contains oxalic acid, which does most of the work. Oxalic acid is far stronger than acetic acid (vinegar). Also, it's inexpensive (a couple dollars for a can of it). If you scrub the contacts of an NES 72-pin connector with a toothbrush dipped in Bar Keepers Friend / water mixture (you have to take the NES apart and remove the 72-pin connector to do that of course), it will work like new for years.

  31. I am guessing that 3rd party game developers had to sign licencing agreements much like they do today, so that can explain why some of the physical cartridge designs are very uniform on one platform, but not on others.

  32. I have Chase HQ II on cartridge for my C64 and that HAS to be using more than 16K, it is quite rich, fast and colourful. I love it actually, much better than the 1st one. But what gives in this case?

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