How Old-School Cassette Tape Drives Played Games | MVG

[Applause] [Music] my first ever introduction to video games was the Commodore 8-bit micros back in 1985 my home computer was a Commodore 64 with a tape drive the tape drive known as a data set was something that I owned as a much cheaper option than the 1541 disk drive which actually cost as much as the machine itself this is the c2n data set for the Commodore line of machines it worked with the Commodore pet vic-20 c64 c16 and plus 4 and the Commodore 128 while there were different models all of them performed the same task to read in data from conventional cassette tapes into the commodore's memory Magnetic Tape storage like this was certainly not invented by Commodore in fact many 8-bit micros of the era use magnetic tape storage as it was an inexpensive storage option in the UK software houses would sell games on cassette if you were lucky enough or lived in Northern America the chances are you would own a 1541 disk drive instead according to computer game World magazine in 1986 97 of commodore systems in the USA own disk drives cassette players like the c2n were popular in Europe and Australia with most game sales on cassette and considered the standard format of the era so how do you actually load games from cassette well simply turn on the c64 put the game into the data set make sure you rewind back to the start a good hint is also to set the tape counter to zero zero zero this is important because you're not really quite sure how long the game may take to load and a tape counter will be your guide on the c64 simply type load and press enter or hold shift and press run stop from here follow the on-screen prompts to press play on tape and at this point the game should go through its loading process and it will take some time and I do mean some time we're talking about between 5 to 10 minutes depending on the game this is because loading games from tape is extremely slow but there are some tricks that developers used to speed up the process now software houses knew that playing games on cassette was tedious and what they would offer on occasion is loading Graphics so there was a nice image to look at while the game was loading but if even better than that was c64 audio or SID music playing through the said chip as the game loaded [Music] [Applause] there was also these horizontal bars that flashed around the Border known as loading bars this was performed all while the game was loading these are visual and audio Clues to let the user know that the game is loading and to continue waiting take for example Rambo First Blood Part 2 by ocean software as the game loads you can see that the loading Graphics are being drawn pretty slowly but what happens if we stop the tape you can see that the graphics stop as well this is a cue to let the user know that there is a problem with the cassette and it's a good idea to start over type plays like this were certainly not exclusive to Commodore in fact other 8-bit micros of the era supported Magnetic Tape storage the c2n however was different because of its digital format now you may be asking how is a tape player digital well to explain further on a computer such as the ZX Spectrum just about any portable tape player could be used as long as there was an analog earphone or line out Jack that could be plugged directly into the computer the c2n uses a proprietary Edge connector that plugs into the tape expansion Port of the Commodore 64. what this means is it's not possible to use any standard regular tape recorder for the c64 there is however aftermarket adapters that you can purchase to do just this but this was certainly not something that was available back in the 80s the advantage of a digital format like this is that it supports error correction but subsequently a disadvantage is that the Commodore data set is slower than conventional analog tape systems but before we get too far ahead of ourselves let's first talk about exactly how a Commodore c64 even knows what to do with Theta found on cassette to start have you ever wondered what a c64 game sounds like on a standard tape player well this is 2022 and I don't own a tape play anymore so let's cheat a little and open up a c64 tape WAV file in Windows here's a listen [Music] [Applause] now this may have some familiarity to you if you're used to the sounds of a dial-up modem in the late 90s and early 2000s but if we zoom in closer on the data you'll note that it's comprised of many different Square wave patterns these square waves are different lengths and that accounts for the differences in sounds these differences in sounds also determine if the binary data is a one or a zero when play is pressed on the tape drive the c64 is waiting for data when the square waves are fed to the c64 there are a maximum of three different Square wave patterns that are encoded on c64 tape these are long medium and short to determine if a 1 or a zero is the next value the c64 sensors when the waveform moves from a greater than zero value to a lesser than zero value this event is called a pulse and causes an interrupt request to be delivered to the C CIA chip on the c64 each byte of data is identified by a long Square wave like this one here and then a one bit is identified by a medium Square wave followed by a small square wave like this one here and a zero bit is identified by a small square wave followed by a medium Square wave now the other interesting thing about the Commodore 64 data set was it had its own error correcting and the way that it would do this was effectively have two copies of the same data on cassette if I enter this basic program and save it to cassette what's happening is it's saving two separate copies of the data one after the other so in the instance if an error occurs during loading the first time round the c64 remembers where the previous error occurred and retries with the second copy of the data of the tape in general commodore's tape format is reliable because of its built-in error correction and detection but this has the side effect of being slower than the analog tape drives of its competition however tape speeds can be significantly sped up by using what's known as a turbo or fast loader this can cut down a 15 minute data load to as little as 5 minutes essentially turbo loaders work by identifying a 1 or a zero as a single Square wave instead of pulses of two or more this compresses down the bits of data but because the standard tape loader on the c64 would be able to interpret this during the initial load of the game from tape the first thing that it must do is put the turbo loader program resident in memory then the program will load the turbo or fast load data almost every c64 game I've played used a turbo loader and there were many different ones on the market to load games from tape on average a normal load time is about four to six minutes developers got creative and did what they could to make that way to load games more bearable and sometimes they went that extra mile in 1987 a fast loader was developed known as Invader load this was developed by Richard applin an experienced c64 and Amiga developer at the time it contained a mini Space Invaders game that only required 8 kilobytes of data four kilobytes was for the absolutely amazing Rob Hubbard Soundtrack This Is A Space Invaders minigame and one that's completely playable as as the main game is loading from cassette this was all done many many years before namco's pattern to prevent other companies from having playable minigames as loading screens Namco may have patented the concept but they were certainly not the first although tape was a suitable format there were many games that were great on floppy disk that did not translate well specifically ones that required multiple loads as you progress through the game would often require the user to either manually fast forward rewind or turn the cassette over to side B to load the next portion of the game multi-load cassette games really broke up the fun and the immersion of the gameplay as you'd need to wait at least another two to five minutes for the next level to load worse if you died you would need to rewind the tape back to where level 1 was stored and reloaded this of course all worked but it was a bit tedious thankfully some games once again had brilliant loading graphics and music such as the last ninja by System 3. now of course Publishers were very concerned about software piracy when it came to cassette it was very easy just to acquire a boombox that had two tape decks and you could simply make a copy of the source cassette now tape copy protection was actually something that was looked into and Incorporated with some levels of success tape copy protection was implemented mainly to stop freezer cartridges such as the action replay to work these could be easily detected by the cartridge Port however straight duplication of tapes was the biggest concern as the average person could simply do it if they had a decent enough tape deck however the results were often inconsistent most of the time a simple tape duplication wouldn't work or would error out this is because a copy of a cassette on a consumer level Hi-Fi would often introduce taped hiss and noise this meant that the square wave patterns that the c64 is looking for would be inconsistent as compared to the original Master on top of this other tricks were used to master the tape with a weak signal but still enough for the data set to read in the data this meant that the tape noise would be audible enough to result in errors and finally most Hi-Fi tape decks record in Stereo but the data set expects data in mono this causes issues as most stereo tape deck heads read mono data on the edges of the tape whereas the data set reads from the center of the magnetic data for that side as we mentioned the c2n has error correction however with the much more compressed fast load data that we talked about earlier it meant that it was easier for tape duplication to fail but with that all said with the right cassette tape a good tape Deck with noise reduction and the right levels of EQ you could pretty much copy any game on the market and this was a major concern for software houses in the UK at the time with the legal bootlegging of games being resold on the used Market this would go away when the world moved to compact discs in the late 90s just kidding they got cracked as well but of course I have a lot of love and Nostalgia for the c64 it is the first system that I ever used and the data set was a necessary Evil by Commodore it was crude but it got the job done and look it really promoted the Commodore brand in many different countries around the world and that's one of the reasons why I think it was the most successful home computer for such a long time but we are going to leave it here for this episode thank you so much for watching guys if you liked it don't forget to leave me a thumbs up and I'll catch you guys in the next video bye for now foreign [Music]

Channel: Modern Vintage Gamer

Views: 410,982

Keywords: modern vintage gamer, mvg, c64, commodore 64, tape drive, cassette player, c2n, datasette, retro, 8 bit, micro, home computer, video games, how stuff works, old school, piracy, copying, duplication, gaming, bedroom coder, fast load, turboload, slow, tapes, micros

Id: cS7SWdTVKys

Length: 12min 0sec (720 seconds)

Published: Mon Nov 21 2022