Issue 3 zeddy no K on screen output
-
- Posts: 2173
- Joined: Sat Nov 26, 2016 2:42 am
Re: Issue 3 zeddy no K on screen output
I built a test ZX8-CCB and attached it to my non functioning zeddy and got no output at all.
I had previously tested my test equipment on a known good zeddy.
So I assume it is not the RF modulator at fault. Does that just leave the ULA / Z80? Both of which are soldered in.
My test setup. In hindsight I should have ordered a bigger box so I could drill two holes to expose the adjusters for fine tuning to individual zeddys.
Something to do another day!
I had previously tested my test equipment on a known good zeddy.
So I assume it is not the RF modulator at fault. Does that just leave the ULA / Z80? Both of which are soldered in.
My test setup. In hindsight I should have ordered a bigger box so I could drill two holes to expose the adjusters for fine tuning to individual zeddys.
Something to do another day!
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
- 1024MAK
- Posts: 5118
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: Issue 3 zeddy no K on screen output
Is it because the Zeddy is scared of the larger computer it is sat on ...
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer later in the year.
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer later in the year.
-
- Posts: 2173
- Joined: Sat Nov 26, 2016 2:42 am
Re: Issue 3 zeddy no K on screen output
I had not considered the intimidation factor before. I will sit it elsewhere!
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
-
- Posts: 2173
- Joined: Sat Nov 26, 2016 2:42 am
Re: Issue 3 zeddy no K on screen output
So I moved my zeddy from on top of the Apple (6502 vs Z80 - just like at school!) and lo and behold it worked!
Well, that and I removed the ULA, fitted a socket and tried another one...
So it was the butler all along! I mean the ULA.
Actually not a bad picture for a 184 ULA
Lardo
Well, that and I removed the ULA, fitted a socket and tried another one...
So it was the butler all along! I mean the ULA.
Actually not a bad picture for a 184 ULA
Lardo
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
- 1024MAK
- Posts: 5118
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: Issue 3 zeddy no K on screen output
Well done that man
Mark
Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer later in the year.
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer later in the year.
Re: Issue 3 zeddy no K on screen output
Nice little enclosure you have! Did you make it?
TS 1000 bought in 1982 and brought back to life by Sir Ian
-
- Posts: 2173
- Joined: Sat Nov 26, 2016 2:42 am
Re: Issue 3 zeddy no K on screen output
I bought the enclosure off eBay, drilled a couple of holes, stuck in a bit of breadboard to isolate the cables from me being clumsy (so just the breadboard gets broken if I yank the cables) and soldered it all together.
In hindsight a bigger box would have been better - very fiddly at that size! Plus I would be able to drill two extra holes to expose the tuning pots.
Lardo
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
- 1024MAK
- Posts: 5118
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: Issue 3 zeddy no K on screen output
Hands up! Now don't move! This is a thread heist!
So, about time I posted a photo of my test ZX8-CCB All right! Get back in your waggon and be on your way...!
Mark
So, about time I posted a photo of my test ZX8-CCB All right! Get back in your waggon and be on your way...!
Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer later in the year.
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer later in the year.
Re: Issue 3 zeddy no K on screen output
Where did you find those nifty clips?
TS 1000 bought in 1982 and brought back to life by Sir Ian
- 1024MAK
- Posts: 5118
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: Issue 3 zeddy no K on screen output
The ones in my photo were obtained via eBay. Search for 'mini hook test clip". They are some of a pack of ten for £0.99. I reduced the length of the hook slightly (cut a bit off the end) so that it is easier to hook under resistor leads.
I also used an inline phono (RCA/cinch) socket (that I already had) and used some lengths of black heat shrink tubing.
Mark
I also used an inline phono (RCA/cinch) socket (that I already had) and used some lengths of black heat shrink tubing.
Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer later in the year.
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer later in the year.