Redesigning a ZX Spectrum 128k - my childhood dream

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    Northern Lights Pinball Show - 27th & 28th October 2018

    Visit the Thread here!!

    Buy your DISCOUNTED tickets here and support this event!

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    Another weekend. Loads more machines. Be there.

myPinballs

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#1
The ZX Spectrum was my favourite thing in the whole world when i was 8. It's what led me into a world of software and hardware design. Every since i first got a rubber keyed 48k, i always thought one day i'll make my own, never really thinking that it would be possible. However with my lifetime of 8-bit pinball hardware repair knowledge always expanding and with me developing my own range of replacement cpu and sound board hardware for various pinball systems over the last few years the thought reappeared in my mind and now didn't feel to far away :)

If you would like to read more about this project i have created an article on my blog page describing the last 18months development of it :) blog.mypinballs.com This project will be part of my NLP stand this year, so we should all be able to have a go on some classic games including the advanced pinball simulator :D

Also here are some pics of how its looking now :) Do you remember the 'Advanced Pinball Simulator'??

IMG_6582.JPG

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The board is now working lovely, has been a major learning curve with some tricky moments, but has been so rewarding. I'll be making my first batch of assembled boards and kits soon so you to can have a new 128k Spectrum in and old case :) The boards will be available like all my other pcbs and products on my web store here.

http://mypinballs.co.uk/electronics/store.jsp


The new boards will feature:

  • Reduced chip count and power consumption
  • Reduced custom chip usage
  • Fully spectrum 128k compatible
  • 8 pages of 16k ram 128k total
  • High quality picture - RGB scart socket with proper tv identification capability.
  • Standard female 21 pin socket for use with stock fully wired scart cables
  • Built in kempston joystick port
  • Built in IDE 40 pin connection
  • Uses the 128k ULA IC - Ferranti 7K010E/Amstrad 40056
  • Full set of test pads
  • Power leds
  • Low power 5v regulator
  • Single 12v supply power in
  • Modern reset chip and on board reset button
  • AY-8912 sound generator on board for retro 80s music
  • AY-8912 expansion connector for 3rd party dev
  • Sound line in for Tape loading or loading wav files
  • Sound line out for connection to amps and playing music
  • Fully compatible card extension port
  • Full plate through design, no SMD
  • Designed and assembled in UK

Finally some videos with classic 128k music (similar to the wonderful gottleib 80b games from the same era :))


 
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Courtney Blush

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#3
Wow, I will need one of these for the museum. It should be on display next to the ZX80, ZX81, 16k Rubber Key, 48k Rubber Key, 48k +, +2, +3, Vega Handheld and Micro TV, missing the toast rack 128 k and the MK14.

I am opening a museum here in Birmingham (The Midlands Retro Museum) which will have displays (interctive) of vintage audio, gaming, computer, console, home life items from 1900 thru present day.
 

Wiredworm

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Apr 7, 2013
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Grimsby
#6
Absolutely amazing work Jim. :)

The ZX Spectrum was my first computer and I think I must have been about 8 when we got it as it was close to launch and I was born in 1974. I spent many many many hours playing games on it and hammering in listings from Input magazine. My parents were highly amused that i'd sit for hours typing in hex DATA statements, only to run the program at the end and find it reboot the machine due to an errant value i'd mistyped. I'd simply sit down and start over again; it's probably the reason why i'm so determined and patient nowadays.

Like you, it's probably also the reason why I have a fascination with electronics, although my skills are far more modest than yours. And despite working as a Server Tech I still dabble a fair bit with Z80 assembler, C# and a few other languages too. :)

I'd definitely be up for buying one of these once they come available. If you have a 'pre-orders' list then please stick me on it.
 
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myPinballs

myPinballs

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#9
Awesome work mate :D The Speccy was my first computer too :thumbs:

Just so I understand, the board is designed so it can be retro-fitted into an empty 128K case? Will it support game loading from an SD card?
Yes, the board will fit into any ZX Spectrum + case or ZX Spectrum 128k ' toastrack' case

The pcb has a fully compatible extension port card slot so you can use any number of 3rd party sd card extensions such as divIDE. Also there is an IDE connector included which can allow Compact Flash memory cards to be plugged in via adapters. I currently load games using the sound in route with WAV files directly on a usb drive played through an amplified speaker.

Plenty of choices :)
 
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stoptap

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#12
Yes, the board will fit into any ZX Spectrum + case or ZX Spectrum 128k ' toastrack' case

The pcb has a fully compatible extension port card slot so you can use any number of 3rd party sd card extensions such as divIDE. Also there is an IDE connector included which can allow Compact Flash memory cards to be plugged in via adapters. I currently load games using the sound in route with WAV files directly on a usb drive played through an amplified speaker.

Plenty of choices :)
Have you tried Speccy Tape Jim ?
It's an IOS app that lets you load games into a Spectrum from an iPhone. You can even download the games directly into the app from World Of Spectrum.
I still occasionally fire up my old rubber key 48k for some Jetpac, Chuckie Egg and Manic Miner fun. Although the picture is starting to get a little wavy now so I will need to replace the caps in it at some point.
 
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myPinballs

myPinballs

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#13
Have you tried Speccy Tape Jim ?
It's an IOS app that lets you load games into a Spectrum from an iPhone. You can even download the games directly into the app from World Of Spectrum.
I still occasionally fire up my old rubber key 48k for some Jetpac, Chuckie Egg and Manic Miner fun. Although the picture is starting to get a little wavy now so I will need to replace the caps in it at some point.
Yes Speccy tape is a nice app but the wos database integration isn't working currently and iOS volume outputs seems a little low on loads
 
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Arv

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Jul 21, 2011
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#15
Can you not plumb in an rj45 like the spectranet board that would be cool.

What about support for those Russian clones?
 

cooldan

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#18
My best mate had a Speccy, I was so jealous as I had a BBC that my dad thought was more 'serious' and that therefore I'd learn programming etc. Did I ********, I played games on it and there were loads of good ones but I still looked forward to going round Alex Charawani's house to play on his Spectrum.

My favourite games were Penetrator, Attic Attack, Jetpac, Zaxxon, Scramble, and of course the Daley Thompson pound-the-keyboard-as-fast-as-you-can Olympic Decathlon one.
 
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RudeDogg1

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#19
My best mate had a Speccy, I was so jealous as I had a BBC that my dad thought was more 'serious' and that therefore I'd learn programming etc. Did I ********, I played games on it and there were loads of good ones but I still looked forward to going round Alex Charawani's house to play on his Spectrum.

My favourite games were Penetrator, Attic Attack, Jetpac, Zaxxon, Scramble, and of course the Daley Thompson pound-the-keyboard-as-fast-as-you-can Olympic Decathlon one.
Did you have grannies garden and Geordie racer? That's the only BBC ones I can remember that we played to death at primary school
 

Wizcat

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#23
Been following on Facebook and well impressed with this project.

C64 was my first though. Begged my Mum and Dad for a while and also did the 'good for my education' bit too. Funnily enough though I *did* start programming on it, and never looked back since :)

I'm hoping Jim had a C64 at one point and has plans for a DIY Commodore project!
 
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DRD

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#24
Like @cooldan , i had a bbc model b. For similar reasons too.

Zalaga was a good one, a very faithful arcade copy for those days ....

image.jpg

Knight lore was my favourite, originally written for the speccy

image.jpg

A niche game called dogfight where two could play at once flying planes doing loop the loops.....

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The spectrum had masses more software available, with much greater sharing opportunities. So saddos with bbc computers had far less fun.

This is a useful site that will help the nostalgia flow ...

http://everygamegoing.com/index.html
 

Pharo

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#25
Knight lore forgot about that one cracking game back then can any body remember the games you got free when you bought a spectrum I don't know if it was the 48k or 128k but I remember playing games called punchy and treasure island is that right.
 

Wiredworm

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Grimsby
#27
Kids coding is making a comeback as my daughter did Scratch at primary school and I'm hoping to get her started with Unity soon as well.

I've been replaying a few of the mentioned classics from the Speccy thanks to Rare Replay on the Xbox One, but Jim's post has reminded me of so many more classics. Really fancy one of these now.
 

Nickbs

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#28
I was at one of the few schools back in the 70's that offered O level computing. With the help of a very enthusiastic. Maths teacher the school acquired the original Commodore Pet & then a Research Machines 380z back in 1977.

I then acquired by own ZX80 when it cam out before upgrading to a ZX81. Acquired A much sought after BBC model B whilst at Uni and managed to be able to do my final year degree project developing software for it. happy days indeed!
 
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myPinballs

myPinballs

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#29
Thanks for all the comments people. Great to hear so many have a speccy story. Be sure to visit me at NLP and check out the prototype :D

Ultimate Play the game wrote arcade games before switching to the speccy hence why their early games were so much better than others. Jetpac and Knightlore are 2 seriously impressive games. Jet Pac was for the 16k speccy to :D

R-type remains my all time favourite and this will be the game playing at NLP along with the advanced pinball simulator mostly i think. The graphics and game play on r-type is almost better than the arcade original. Wonderful stuff. Just wish they had released an extra special version for the 128k.

Next up on the prototype journey is to populate the kempston joystick parts and test out some zipstiks that i picked up off ebay recently.
 

Wiredworm

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Grimsby
#30
Will be sure to stop by at NLP.

On a related note i've got a little project on the go where i'm reverse engineering the ASM code for Manic Miner as a means to learn Z80 assembler. It makes you realise just how much effort it took to get things moving in the old days. Developers are spoilt nowadays.