Live data from Hacker News

Show HN: I recovered one of my earliest ZX-Spectrum games from an audio cassette

news.ycombinator.com

1–10 of 18 posts

Show HN: I recovered one of my earliest ZX-Spectrum games from an audio cassette

#1
Recently, I managed to recover some of my earliest work from the ZX Spectrum era from an old audio cassette.

It is a mini-game, that I created as a teen, called "Atomix," written in BASIC with a mix of Z80 assembly — some of which I coded myself, while other parts were disassembled from existing games. I put the game in an modern emulator and recorded a screencast. See the video in my linkedin post:

https://www.linkedin.com/feed/update/urn:li:activity:7288665...

Re: Show HN: I recovered one of my earliest ZX-Spectrum games from an audio cassette

#2
Well done. Speaks volumes (sorry) to the robustness of the encoding model.

This was Kansas City Standard? 300bps. The zx format is I believe much the same.

My audio tapes from this period are badly affected by heat, and stretching (I made a geared tape rewinder out of meccano which worked but was not kind to tape)

Re: Show HN: I recovered one of my earliest ZX-Spectrum games from an audio cassette

#3
That's so cool!! I'm kind of sad I mostly missed that era of computing. Always thought the ZX Spectrum was a cool system. It's neat that writing your own software was accessible and practical all the way back then. I'll probably buy one when I have the money and room to collect that sort of thing.

There's something that seems very satisfying about loading software from tape, too.

That's what I love about coding. All you need is a computer and an idea and nobody can stop you creating it.

Re: Show HN: I recovered one of my earliest ZX-Spectrum games from an audio cassette

#4

That's so cool!! I'm kind of sad I mostly missed that era of computing. Always thought the ZX Spectrum was a cool system. It's neat that writing your own software was accessible and practical all the way back then. I'll probably buy one when I have the money and room to collect that sort of thing. There's something that seems very satisfying about loading software from tape, too. That's what I love about coding. All…

You haven’t missed it! It’s still there! My kids are learning Scratch - but they are also learning C on the Vic-20 (6502 cpu), which is simple enough that the disassembly is easy to understand. The compiler and IDE are cc65 and VSCode - the commodore keyboard is very bad and it’s a lot easier to run the debugger/monitor on an emulator.

Re: Show HN: I recovered one of my earliest ZX-Spectrum games from an audio cassette

#5

That's so cool!! I'm kind of sad I mostly missed that era of computing. Always thought the ZX Spectrum was a cool system. It's neat that writing your own software was accessible and practical all the way back then. I'll probably buy one when I have the money and room to collect that sort of thing. There's something that seems very satisfying about loading software from tape, too. That's what I love about coding. All…

You can get back to it, :)

https://retrogames.biz/products/thespectrum/

Re: Show HN: I recovered one of my earliest ZX-Spectrum games from an audio cassette

#6
post #5

That's so cool!! I'm kind of sad I mostly missed that era of computing. Always thought the ZX Spectrum was a cool system. It's neat that writing your own software was accessible and practical all the way back then. I'll probably buy one when I have the money and room to collect that sort of thing. There's something that seems very satisfying about loading software from tape, too. That's what I love about coding. All…

You can get back to it, :) https://retrogames.biz/products/thespectrum/

Unfortunately, it's not sold in the Netherlands :-(

Re: Show HN: I recovered one of my earliest ZX-Spectrum games from an audio cassette

#7
post #6
post #5

Earlier quoted context omitted.

You can get back to it, :) https://retrogames.biz/products/thespectrum/

Unfortunately, it's not sold in the Netherlands :-(

I thought it was everywhere in Europe, I can guarantee that at least in Portugal, Spain and Germany I have seen them at plenty of electronic stores during Christmas.

Re: Show HN: I recovered one of my earliest ZX-Spectrum games from an audio cassette

#8
post #2

Well done. Speaks volumes (sorry) to the robustness of the encoding model. This was Kansas City Standard? 300bps. The zx format is I believe much the same. My audio tapes from this period are badly affected by heat, and stretching (I made a geared tape rewinder out of meccano which worked but was not kind to tape)

The ZX Spectrum ROM loader is 1500bps and some games loaded at over 3000. There wasn't any encoding, just straight-up 1s and 0s straight into RAM.

Re: Show HN: I recovered one of my earliest ZX-Spectrum games from an audio cassette

#9

That's so cool!! I'm kind of sad I mostly missed that era of computing. Always thought the ZX Spectrum was a cool system. It's neat that writing your own software was accessible and practical all the way back then. I'll probably buy one when I have the money and room to collect that sort of thing. There's something that seems very satisfying about loading software from tape, too. That's what I love about coding. All…

> There's something that seems very satisfying about loading software from tape, too.

Uhhh.. as someone who used to load software from tape on a CPC 464 ages ago, I can tell you that it was painfully slow. Nothing satisfying about it for me...

Re: Show HN: I recovered one of my earliest ZX-Spectrum games from an audio cassette

#10

That's so cool!! I'm kind of sad I mostly missed that era of computing. Always thought the ZX Spectrum was a cool system. It's neat that writing your own software was accessible and practical all the way back then. I'll probably buy one when I have the money and room to collect that sort of thing. There's something that seems very satisfying about loading software from tape, too. That's what I love about coding. All…

> There's something that seems very satisfying about loading software from tape, too. Uhhh.. as someone who used to load software from tape on a CPC 464 ages ago, I can tell you that it was painfully slow. Nothing satisfying about it for me...

You might like my Amstrad CPC demo from 10 years ago called Breaking Baud.

It was a custom turbo loader for the CPC that had a co-operative multi-tasking thing going on, so it had a loader, music player, realtime data decompressor and some spare time left to do some other things.

I had plans to make the demo even better, but actually what got produced was quite pure because everything, literally EVERYTHING, is loaded directly into RAM and then decompressed in place (that's what the random white flashes are you might see at times - it's usually where a RLE marker was placed in RAM and shown by the display hardware before the background task to expand/copy the RLE section was executed).

As such, every step of the animations loaded could actually a full screen independent of the last, it's just most of the time it compresses super easily as the delta from what's already in the memory at that point is very small.

The live capture of the demo as it was presented live for the first time is here: https://www.youtube.com/watch?v=D62jpqZ6TG4 Someone else running it on real hardware (but sadly turned down the tape volume after a minute or so): https://www.youtube.com/watch?v=G7HEK1B2oIc

This is a very early prototype that actually shows the speed of loading completely unrelated images, just relying on compression - some of the screens load 16KB in around 10 seconds: https://www.youtube.com/watch?v=qfGcvWOaFFw (BUT BE WARNED IF YOU ARE SENSITIVE TO FLICKER)

Post reply on HN