Sinclair ZX80 / ZX81 / Z88 Forums

Hi. I came across all this Ferranti ULA 5C114E dated 8344.. These are related to de Czerweny Factory that made several spectrum clones at that time. First ones named CZ2000 had an ISSUE 6A board. Later "CZ Spectrum" model had a different case with same keyboard and rubber membrane and a slightly modified board (low ram only uses +5v, it had two joystick ports and a reset button, rom was not modified). But mine at least had the comon ULA 60001E-7 type. On Google I only found that this ULA model was found on a rare NTSC Spectrum from Chile. But here we have PAL-N TV broadcast..
The last model released by Czerweny was the "CZ Spectrum Plus" wich had the same keyboard as de 48+ and I think the rom was that of the "Spectrum" by Investronica in Spain..
Would it be safe to test one of these ULA on my CZ spectrum clones? (I don't have any of these last plus models)

Hi,

Interesting findings. Anyway, in Europe PAL-B/G is used and its colour subcarrier frequency is 4.43361875 MHz. In case of PAL-N, the colour subcarrier frequency is 3.58205625 MHz and a channel bandwidth of 6MHz. So, PAL-N spec is very close to the NTSC spec, and it might be a reason why Sinclair offered NTSC version of ULA in your part of the world.

Hmm

16K / 48K models

U.K. / Europe 50Hz PAL versions

• ULA 5C102E - used on issue 1 and some issue 2 boards. Needs the “dead cockroach”. Although not known at the time of the production of the issue 1 boards, the “spider” modification is also needed.
• ULA 5C112E - used on issue 2 boards. Needs the “spider” modification.
• ULA 6C001E-6 - used on issue 3 boards. The PCB incorporates the “spider” circuitry as standard.
• ULA 6C001E-7 - used on issue 4 boards to issue 6A boards. Backwards compatible for use on earlier boards.

Earlier ULAs are not recommended for later boards, as changes introduced in the internal circuitry are likely to result in unreliable operation.

All these versions produce a video signal with 312 lines per frame with a scan line time of 64us. The frame rate is 50Hz. PAL inverts the phase of the chrominance V component on alternative scan lines.
Note that the ULA outputs YUV video signals with the Y being inverted.

60Hz NTSC

• ULA 6C011E-3 - used in machines sold in Chile, South America. The Master clock crystal is 14.11MHz. This version produces 264 lines per frame with scan line time of 63.5us. The frame rate is 59.65Hz.
  With this colour system, there is no need to invert the phase of the chrominance V component on alternative scan lines, hence this feature is disabled.

• ULA 5C114E - suspected to be NTSC / 60Hz but not confirmed by any second source (for the first source, see here and here)

128 ULA 50Hz PAL

• ULA 7K010E-5 - used in the ZX Spectrum 128 and +2 (grey)

Mark

bola_dor wrote: ↑Thu Jul 30, 2020 2:24 am Hi. I came across all this Ferranti ULA 5C114E dated 8344..

bola_dor wrote: ↑Thu Jul 30, 2020 2:24 amWould it be safe to test one of these ULA on my CZ spectrum clones? (I don't have any of these last plus models)

See here.
So going on that, I don’t think you will do any damage. But the 5C ULA chips have less compatible DRAM timing compared to the 6C001E-7. And you say that the board that you have is based on an issue 6A (which over here uses a 6C001E-7). So as well as a NTSC video display (which will not be quite right due to the ULA clock speed being slightly out and a PAL colour encoder being used), the ‘lower’ DRAM may not be happy with the sub-standard control and address timing.

Be fun though

Mark

McKlaud wrote: ↑Thu Jul 30, 2020 7:48 am Anyway, in Europe PAL-B/G is used and its colour subcarrier frequency is 4.43361875 MHz.

The U.K. used ITU system I-PAL (ITU standard here) which is very similar, it just has a slightly wider bandwidth and a different off-set carrier frequency for the audio sound channel.

McKlaud wrote: ↑Thu Jul 30, 2020 7:48 amIn case of PAL-N, the colour subcarrier frequency is 3.58205625 MHz and a channel bandwidth of 6MHz. So, PAL-N spec is very close to the NTSC spec, and it might be a reason why Sinclair offered NTSC version of ULA in your part of the world.

The colour subcarrier frequency is a function of the LM1889 colour encoder in the 16K/48K systems. If 625 line / 50Hz timing and PAL colour is needed, a PAL ULA must be used.

Mark

1024MAK wrote: ↑Thu Jul 30, 2020 1:37 pm

bola_dor wrote: ↑Thu Jul 30, 2020 2:24 am Hi. I came across all this Ferranti ULA 5C114E dated 8344..

bola_dor wrote: ↑Thu Jul 30, 2020 2:24 amWould it be safe to test one of these ULA on my CZ spectrum clones? (I don't have any of these last plus models)

See here.
So going on that, I don’t think you will do any damage. But the 5C ULA chips have less compatible DRAM timing compared to the 6C001E-7. And you say that the board that you have is based on an issue 6A (which over here uses a 6C001E-7). So as well as a NTSC video display (which will not be quite right due to the ULA clock speed being slightly out and a PAL colour encoder being used), the ‘lower’ DRAM may not be happy with the sub-standard control and address timing.

Be fun though

Mark

These are new old stock from the CZERWENY Factory in Argentina.. they never made NTSC computers...(mines are all PAL-N) they had a fire that put them down and then another firm took the leftovers and made some machines but there's a black hole in the history there.. Chilean NTSC Spectrum were not made here (as far as I know) they weren't very common... could be a missed proyect.(?)..

Well, the information that the 5C114E comes from only a single source. So it’s possible that the 5C114E Has PAL timing.

Until someone conducts a new test using a 5C114E, it’s all just speculation...

Mark

BTW the source of the info on the 5C114 is here.

Mark

1024MAK wrote: ↑Thu Jul 30, 2020 7:21 pm BTW the source of the info on the 5C114 is here.

Mark

I followed that post but couldn't find the test they used.. there lost of broken links..
I will test one of then on my machines.. that have PAL crystals but may be thebTV can see something on RFvor on composite..
If you konw any test to perform or how to see how many lines per frame is it generating or fps please let me know
I could get an oscilloscope to test the output too..

Unfortunately with forums that don’t allow uploads/attachments, it’s inevitable that there will be broken links all over the place. The broken link to the photo of the board that presumably is/was fitted with a 5C114E is also really frustrating.

Mark