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Re: Ferranti ULA 5C114E info?
Posted: Wed Oct 07, 2020 1:47 pm
by Moggy
1024MAK wrote: ↑Wed Oct 07, 2020 9:10 am
RobG wrote: ↑Tue Oct 06, 2020 6:19 pm
BTW, which memory bypass caps were problematic, the glass ones or the black ones?
In terms of reducing the visible artefacts that are often referred to as jail bars, it’s not that the capacitors fitted are defective. It’s more along the lines that people expect a much better picture on their higher resolution TVs today compared to in the 1980s when most home computers were being used with 14” CRT TVs.
Mark
Just to add to this. There can be differences between modern sets as well.
For example when I first put my Atari STe through a top quality LCD monitor the jail-bars were horrendous to the point of almost being unwatchable (I am aware of the various solutions out there), however when used with my bargain basement LCD TV not only is the picture still sharp and clear but the jail-bars have disappeared completely.
Re: Ferranti ULA 5C114E info?
Posted: Wed Oct 14, 2020 2:14 am
by RobG
I got some interesting news about my 5C114E ZX Spectrum. According to the person I got it from, my ZX came in a box full of Sinclair related products, mostly TS1000 and TS2068 machines. The box was removed during cleanup from server room of some company located in Middlebury, CT. Well, Timex's HQ was located in Middlebury, CT (I had a pleasure of visiting it once back in early 90's when I bought my TS2068 from one of the employees.) So, looks like my ZX is a genuine 5C114E model!
Re: Ferranti ULA 5C114E info?
Posted: Wed Oct 14, 2020 11:06 am
by 1024MAK
RobG wrote: ↑Wed Oct 14, 2020 2:14 amSo, looks like my ZX is a genuine 5C114E model!
Or was a U.K. model partly modified...
Can you please confirm what TV / video picture standard it’s producing?
And which type of modulator is or was fitted?
Mark
Re: Ferranti ULA 5C114E info?
Posted: Wed Oct 14, 2020 11:24 am
by 1024MAK
As a comparison, here are a couple of photos of an issue 2 U.K. board produced around March/April 1983:
- U.K. issue 2 ZX Spectrum board #1
- U.K. issue 2 ZX Spectrum board #1, close up showing ULA and crystals
And a slightly earlier issue 2 U.K. board produced around February 1983:
- U.K. issue 2 ZX Spectrum board #2
- U.K. issue 2 ZX Spectrum board #2, close up showing ULA and crystals
Note that the Z80 has been replaced at some time.
Mark
Re: Ferranti ULA 5C114E info?
Posted: Thu Oct 15, 2020 9:12 pm
by RobG
1024MAK wrote: ↑Wed Oct 14, 2020 11:06 am
Or was a U.K. model partly modified...
Can you please confirm what TV / video picture standard it’s producing?
And which type of modulator is or was fitted?
It looks like there are only 3 differences (compared to UK boards:) ULA, color burst crystal, DC jack.
Perhaps this is a prototype or a pilot version (since it was found at Timex's headquarters.)
It is definitely NTSC and it has standard modulator (UM1233)
Re: Ferranti ULA 5C114E info?
Posted: Fri Oct 16, 2020 8:21 am
by 1024MAK
RobG wrote: ↑Thu Oct 15, 2020 9:12 pm
1024MAK wrote: ↑Wed Oct 14, 2020 11:06 am
Or was a U.K. model partly modified...
Can you please confirm what TV / video picture standard it’s producing?
And which type of modulator is or was fitted?
It looks like there are only 3 differences (compared to UK boards:) ULA, color burst crystal, DC jack.
Perhaps this is a prototype or a pilot version (since it was found at Timex's headquarters.)
It is definitely NTSC and it has standard modulator (UM1233)
With a UHF channel 36 UM1233 modulator, it does point to being a prototype or similar unit.
Mark