Why Loading Bars on 80s Micros? [Byte Size] | Nostalgia Nerd

Why Loading Bars on 80s Micros? [Byte Size] | Nostalgia Nerd


If you’ve ever owned one of the more popular
8 bit home computers, and you had software on tape, then you’re almost certainly familiar
with loading bands, loading lines or raster bars, whatever you choose to call them. These multi coloured bands would grace our
home television screens as data streamed in at a baud rate similar to that of early dial
up modems, and for a kid in the ’80s, these multi coloured flashing bands were pretty
awe inspiring just in themselves, but what exactly do these lines mean? Well, first we need to understand how the
data is stored. Software is encoded on tape as a sequence of pulses, the same as would
transmit data to Freeserve in the late 90s over your 56k modem. Since many 8 bit machines
had only a rudimentary tape interface, data was recorded using an unusually simple and
very reliable modulation, similar to pulse-width modulation but without a constant clock rate.
These pulses of different widths (durations) represent 0s and 1s, which are interpreted
by the ROM and CPU into usable code. Because of the problems often faced with loading
data from cassette, solutions were devised to keep the user informed their software was
loading correctly. However not all computers graced their users with this feature, for
example, the BBC Micro, Acorn and Dragon 32 would usually show a loading screen, but a
lot of the time, no other loading cues were provided to reassure the anxious gamer. The original source of these lines could be
charted back to Clive Sinclair’s early machine, the ZX81. This early home computer did have
loading bands, but in this case they were simply a quirk of the design. The cassette
audio in used the same pin on the ULA chip as the display, hence an interference pattern
would be displayed. Handily, the width of the bars on this interference pattern could
actually be used to determine the correct volume for the tape output. A volume set too
low, or too high could crash the loading process out as the machine struggled to either receive
a signal strong enough or received a signal which was too distorted to be usable. Sinclair’s later machine, the Spectrum adopted
these bands as an official part of the loading routine, and in the case of this machine,
these bands were intentional and hard coded into ROM. Slow and thick Cyan and Red bands
would indicate searching, or the pilot signal for the data. Thinner Blue and Yellow bands
indicate header and data blocks loading into memory. You can see this at the start of most
software loads, where a header is received and displayed on screen straight away. This
happens quickly as the header file is only about 15 bytes, and the Spectrum loads at
roughly 1,300 bits per second, or 160 bytes. This rate varies, and the thinner the stripe,
the higher the baud rate. It’s actually possible to alter the border
colours by modifying the parameters of many custom loaders and making the border flashing
with multicoloured stripes to obtain a fancy border effect during the loading process.
The centre of the screen can be used to display graphics, information of even games whilst
loading. Over on other machines such as the Commodore
64, and Amstrad CPC, the raster bars work a little differently… If you load software on either of these machines,
you may notice that some titles will load without any banding appearing at all, just
like the Acorn machines. However usually the loading band routines
are added by the software coders themselves, and each publisher tended to have their own
signature loader. Some software will load by changing the border colour for each data
block loaded. Some will display an on screen counter, but most will use multi coloured
bands, which were universally recognised from Sinclair users, and allowed easy manipulation
of the screen in both terms of processing time and loading time, providing more time
& cycles to load the software, rather than some fancy loading sequence. The C64 also differs in that the cassette
data sound isn’t played through your television’s speaker, making a loading routine even more
important for signifying everything is a-ok. Of course, this allowed coders to utilise
the 64’s brilliant SID chip and play music whilst loading, to ease the tedious time spent
waiting for Daily Thompson’s Decathlon to spring to life. This was more of a necessity
on the 64, as the original datasette would load at roughly 50 bytes per second, although
in the later ’80s turbo tape software arrived, which allowed software to load a lot faster
through improved decoding and compression methods. If you’re wondering why the programmers never
opted for vertical bars. The simple answer is simple; it would require precise screen
timing, and this differs between NTSC and PAL. TV’s naturally scan from top to bottom,
left to right, so plonking some arbitrary colours on screen whilst it refreshes is the
natural choice. In the Commodore this can be done from a single memory address. And so ends the tale of 8 bit raster bars.

100 thoughts on “Why Loading Bars on 80s Micros? [Byte Size] | Nostalgia Nerd

  1. I hated the ones on the C64 that, if you had the telly volume up, played the cassette audio (or a derivative thereof) through the speakers at the beginning of the turbo load sequence. I think Commando is one of those. I used to call them "Squealy" loaders. Thankfully the data sound was quickly replaced by loading music 🙂

  2. All wr have now is a little loading bar that doesn't even show you how much has been loaded or it's being loaded at all. For that we would have to go to task manager and look up the cpu and or disk usage.

  3. I never knew that existed. The only cassette based computer I had was the TI99/4A. Once I got my C128 I bought the disk drive with it.

  4. Wow. So I finally found out what the Last Ninja Loading Tunes are for on the C64. Of course, when it takes to play the tape for minutes it makes sense to have some music there.

  5. c64….
    4-6 minutes of load time… I know those days very very well..
    Epyx fast load cartridge was gold back in the day – loads 6 times faster.
    FIBER0PTIC/FBR, The HUMBLE Guys, Napalm & Worship…

  6. A friend had a fastloader copy of Last Ninja II, where the loading bars were small white bars on a black background, more like white noise than the normal full width bars. They were awesome. 🙂 Can't find it anywhere online though, anyone knows about it?

  7. On my C64 I could always tell when one of my tapes was shot because the raster bars would be all thin and messed up.

  8. No wonder the kids of today have no patience; they weren’t trained in the ways of tape loaded games.

  9. The title suggests it was normal, but my experience was the opposite – the Pet, Apple ][, BBC micros all loaded without raster bars and a steady screen.

    However the Sinclair ZX80 & ZX81 used the processor to generate the screen which means that when loading there was no time to process the screen and the tape input at the same time. To show something was happening on the ZX81 (at least IIRC) the tape in pin was connected to the video out circuitry which meant that the display became an image of the loading data – people became proficient at looking at a screen and being able to tell you what part of a program was loading (by the patterns of the bars).

    For the ZX82^WSpectrum Sinclair was using a ULA to generate the screen and so could have used a system of numbers to let you know how far the loading had gone, but stayed with their familiar raster bars but only on the border.

  10. I remember being 4 or 5 and being legit freaked out by these on my C64 at the time. Feud was the worst for me!

  11. ZX Spectrum also changes the border lines with an address although it's an IO address not a memory address like the 64. It's the lowest 3 bits of port 254. e.g. OUT 254,1

  12. The C64's built-in tape loading routine completely blanked the screen. How boring. I never saw raster bars when loading stuff from tapes. Then again, I didn't use tapes all that much, not when a disk drive was available. I did see raster bars on some disk loading screens, though.

  13. What fucknut would give this video a thumbs down? Anyways I can say I was "THERE" from the VERY beginning of video gaming and I'm still as fucking immature as back then!

  14. the way your videos start with spectrum loading borders with an image that 'loads' completely unlike a spectrum makes me eyetwitch every time

  15. Thank fuck for tape loaders. They made loading games on the Datassette way less tedious. Of course the 1541 Disk drive wasn't overly fast either. LOL. I had my Datassette when I had my VIC-20. It wasn't so bad with that because VIC games were not overly big, but once I upgraded to the C64, boy oh boy, was it ever slow. PS: I live in Canada, and the datassete wasn't as popular here with the C64 because most people had disk drives, I eventually got my 1541 about a month after getting my C64. The datassette was still the second most popular medium on the VIC here though, with Cartridges being the most popular.

  16. Now if someone could make a video about raster bars showing up during a loading of a DVD/Blu-ray (with a loading screen before the menu and options).

  17. Congratulations! This kind of videos of yours are simple, short and effective, and that is one of the best. Deeper than the usual jokes about 80’s retrocomputing ; ) Thank you

  18. Interesting! Now I wonder how it could load stuff for the loading screen and game at the same time, like to load loading graphics and music into memory. Surely that would slightly slow down the actual game loading?

  19. So what's the joke with Daley Thompson's Decathelon? I've heard british gamers make a lot of mentions about it when talking about old games

  20. Hold on, you also missed mentioning the Amiga. Although it's wasn't for loading, you'd very often get raster bars when unpacking. PowerPacker, ByteKiller and others could also have them if the coder wanted. I used to use them all the time as it was very simple to do by just changing COLOR00 usually, depending on how many bitplanes you'd got active. Come on, tell people about this! Or I could tell you and show you exactly how it's done.

  21. Huh, I had sort of decided that on the C64 that they were using the video memory for data-transfer or something to make loading faster and that that was why you saw the colors. Well, now I know.

  22. I will still never know just how many hours of my childhood were spent watching these bars flash and waiting for the game to load in though.

  23. My brother and I went to show my mom the game "Garbage" on our Timex Sinclair 1000 that we typed in from a book. She saw the raster bars and asked if that was the garbage. Random memory that I somehow never forgot from 35 years ago 😀

  24. I remember how smug I felt back then when I bought my first microcomputer, opting to go straight for a CPC 6128 with its floppy disk drive. It literally saved me hours upon hours of waiting for games to load on cassettes… that is, until I decided to save a few bucks on certain games buying them on cassette anyway, and then I was worse off because regular cassette players usually worked like crap when you tried to connect them to the computer. And I don't know about other people, but even with original tapes I had a depressingly high amount of read error with some games, and only with a few of them I could resume the load process if there had been an error (with most you had to start over from the very beginning).

  25. I remember my copy of Buggy Boy on the C64 was so temperamental I had to sit completely still for 20 mins whilst it loaded. Otherwise.. crash. Also : remember using the tiny wire at the back to soft reset the machine and enter pokes/ sys commands 🙂

  26. Ahhh the memories. LOADING…… yes! FUZZY BARS & NOISE….. yeeeeeessss!! PICTURE APPEARING……….. ya dancer!!! MORE FUZZY BARS……… Yippee!!!!!

    CRASHED…… SHIT!!!!!!!!!!!!

  27. I don't remember raster bars when loading from tape on my VIC-20 or my TI-99/4A. Though the TI did make lots of lovely noises; its tape format appeared to be packetized and have a distinctive carrier tone of F above high C, giving tape data for the TI a musical, rhythmic crunching quality.

    In retrospect the raster bars are a neat hack. Changing the border color involves poking to a single memory location, something easily done and taking close to no time at all in the middle of a tight loop processing and verifying incoming tape data and giving immediate feedback into how the load is going. Something our modern computer culture, with its vague icons and "something went wrong" error messages, just can't tolerate, alas.

  28. the Sinclair Spectrum Lodingroutine was equal to the Apple II routine, so with some tricks (the missing Header Informations), the Spectrum was able to read Apple Tapes.
    So I could transfer Pictures from the Apple II to the Specky

  29. Happy memories. I learned Sinclair Basic in a Friday afternoon and programmed an app over the weekend with my Speccy 48. Brilliant version of Basic, terrible keyboard.

  30. 0:42 "Well, first we need to understand how data is stored." No, we need to understand how data ARE stored.

  31. Why didn't I think of this back in the day….but….many CRT TV's had analog controls to allow you to "tweak" the viewing area size. So I guess you could increase the image almost to the point where the load bars are mostly off screen? Of course this would be annoying if the TV was also used as a …..TV. As you'd have to keep resizing. Maybe that's why I didn't do it back in the day. Coz it would piss my dad or my brother off 😀

  32. NAMCO's patent on "loading games" (which expired in 2015) has always irritated me, because Joe Blade 2 did it first. Gah!

  33. From my memories of the CPC. Mid to late in that machines life all games displayed the raster border effect plus fast loading. Loading screens displayed quicker and I recall one game playing a tune too.

  34. Reminds me of a PC I used that had the headphone jack right beside the USB port. It wasn't well shielded, so if I had headphones plugged in but no music on, I could hear noise as the data transferred from my USB stick.

    Eventually I fried that USB stick with an accidental jolt of static electricity. I could immediately tell because, instead of the usual patterns of data being transferred, I'd just hear a solid tone for a few seconds before Windows reported an error. Clearly the USB part was still working but no actual data was being sent from the flash chip anymore…

  35. This would have been a nice feature to have as the version of the Radio Shack Color Computer did not do this, I had the early 16k one with the terrible keyboard https://upload.wikimedia.org/wikipedia/commons/thumb/2/20/TRS-80_Color_Computer_1_front_right.jpg/300px-TRS-80_Color_Computer_1_front_right.jpg

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