Andy Rea's original ULA design blog/schematic.
Andy Rea's original ULA design blog/schematic.
Re-discovered this whilst browsing other things and thought it worthy of repost on the the site for historical reasons if nothing else and also for the techies who may learn something from the text.
http://www.rtin.be/zx81/ZX81.ULA.Replac ... 12.43).htm
Also this..
http://www.rtin.be/zx81/ZX81.ULA.Replac ... 41.45).htm
http://www.rtin.be/zx81/ZX81.ULA.Replac ... 12.43).htm
Also this..
http://www.rtin.be/zx81/ZX81.ULA.Replac ... 41.45).htm
Last edited by Moggy on Sat Aug 27, 2022 7:33 pm, edited 1 time in total.
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Re: Andy Rea's original ULA design blog/schematic.
Thanks Moggy.
I only get raw html on the first link but the second one works fine and shows schematics.
I only get raw html on the first link but the second one works fine and shows schematics.
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
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- Posts: 45
- Joined: Sun Nov 03, 2019 9:56 am
Re: Andy Rea's original ULA design blog/schematic.
Cheers for posting the link. This will come in very useful.
Re: Andy Rea's original ULA design blog/schematic.
That's weird Lardo!
Works for me with Firefox win 7 but not google chrome win10!
However the html in this zip should work.
This is already on the forum courtesy of Mrtinb.
Also archived here...
http://web.archive.org/web/200904262218 ... A/ula.html
Works for me with Firefox win 7 but not google chrome win10!
However the html in this zip should work.
This is already on the forum courtesy of Mrtinb.
Also archived here...
http://web.archive.org/web/200904262218 ... A/ula.html
- Attachments
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- ZX81 ULA Replacement ula.zip
- (370.93 KiB) Downloaded 132 times
Re: Andy Rea's original ULA design blog/schematic.
I just thought these documents were valuable, so I downloaded them from Internet Archive Wayback Machine (web.archive.org), as the original homepage was gone.
You can see the pages in Firefox. The files are a webarchive, where pictures are included into the HTML.
You can see the pages in Firefox. The files are a webarchive, where pictures are included into the HTML.
Re: Andy Rea's original ULA design blog/schematic.
Hi, do you know if Andy still has the ULA to sell?
I cannot find this information.
mrtinb I saw on one of your posts that you bought a Andy´s ULA.
Could you please take a good quality photo of the Top and the back of the ULA and post the photos here?
Thanks
I cannot find this information.
mrtinb I saw on one of your posts that you bought a Andy´s ULA.
Could you please take a good quality photo of the Top and the back of the ULA and post the photos here?
Thanks
Last edited by dognaldo on Thu Oct 20, 2022 8:59 pm, edited 1 time in total.
Re: Andy Rea's original ULA design blog/schematic.
Andy has left the zeddy community
In theory, there is no difference between theory and practice. But, in practice, there is.
Re: Andy Rea's original ULA design blog/schematic.
If you want to buy a ULA replacement, there is the vLA81:
https://www.sellmyretro.com/offer/details/38492
https://www.vretrodesign.com/products/v ... eplacement
https://www.tindie.com/products/Charlie ... placement/
https://www.sellmyretro.com/offer/details/38492
https://www.vretrodesign.com/products/v ... eplacement
https://www.tindie.com/products/Charlie ... placement/
Re: Andy Rea's original ULA design blog/schematic.
Paul, Martin,
Thanks for the answers.
I'm going to buy a Vla81 from Vretro.
But regardless of buying one I decided to set up a ULA just like Andy's reading the forum topics.
That's why I asked for the photos.
Thanks for the answers.
I'm going to buy a Vla81 from Vretro.
But regardless of buying one I decided to set up a ULA just like Andy's reading the forum topics.
That's why I asked for the photos.
Re: Andy Rea's original ULA design blog/schematic.
There are some pictures of it in this topic:
https://sinclairzxworld.com/viewtopic.php?f=8&t=2928
The design ZIP file in this topic is for an older design.
https://sinclairzxworld.com/viewtopic.php?f=8&t=2928
The design ZIP file in this topic is for an older design.