Enterprise Forever
:UK => Hardware => Topic started by: John Fante on 2018.July.30. 18:22:38
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I am running my EP's RGB output through a Open Source Scan Converter. A fantastic kit that gives a great picture on a modern monitor :-)
I am finetuning the settings at the moment and have come a cross an effect that I would like to know if iis intended. It is from the game Chimera that I found on EpJatek disk 2.
As you can see from the video below there is some small "noise" in letters at the bottom and some jittering in the graphics on the side. Is that normal for this game?
Link to Chimera video (https://www.dropbox.com/s/uv7djrpv274kdvr/Chimera.m4v?dl=0)
Thank you in advance!
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You have also a Nick from "bad" series, the noise and the extra characters at the bottom of the screen shows that, my EP has also this kind of Nick chip, some speccy conversions had this noise which did not have black border, and showed the extra characters also (for example in Turbo Esprit, and there was noise and jumping screen in The way of the exploding fist, now I remember only these 2 games)
I think the border effect is not fix on the side, because timing problem in the code.
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John's machine from me, with selected Nick chip. At me on old good CRT don't see any strange effect.
I don't found this game on ep128.hu. Probably removed because buggy?
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John's machine from me, with selected Nick chip. At me on old good CRT don't see any strange effect.
I don't found this game on ep128.hu. Probably removed because buggy?
It is on this disk (https://www.dropbox.com/s/byxmofv2jypcej7/Disk2.hfe.zip?dl=0).
It is in .hfe format since I am using it in my HxC. I have the original files on another PC atm.
I must admit I can not remember where I got the files originally. They have been on my machine for years ... :-)
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John's machine from me, with selected Nick chip. At me on old good CRT don't see any strange effect.
I don't found this game on ep128.hu. Probably removed because buggy?
It is strange, the machine produce the same effect as mine produced back in the eighties and nineties, please try The Way of the Exploding Fist, and Turbo Esprit also, if they produce similar extra character and 'noise' in the bottom, and please try attribute pictures with IView if the machune produce strange pixels on the screen, probably these 2 things shows different Nick 'problems'?
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I think the weird border is just how this game looks. I've tried loading the game into the ep128emu emulator and I still get the same unstable border.
I believe the game is a spectrum conversion and the spectrum code rewrites the border to achieve a multi-coloured effect (see attached image - it only happens on the menu because the actual game doesn't use this effect). But this doesn't work on the Enterprise because the CPU timings are different from the Spectrum.
Is it even possible to have stable border effects on the Enterprise? On the Spectrum the Z80 CPU and the graphics ULA run from the same clock, so you can time the Z80 code exactly.
On the EP, the Z80 and Nick chip run on different clocks which I guess means that you can't predict the exact timings for how long the Nick chip is going to delay the Z80. Perhaps if the variation is only a few clock cycles different and this happens during the horizontal blanking then it would work. Or maybe you would have to set up Nick interrupts and use them to do the timing?...
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I think the weird border is just how this game looks. I've tried loading the game into the ep128emu emulator and I still get the same unstable border.
I believe the game is a spectrum conversion and the spectrum code rewrites the border to achieve a multi-coloured effect (see attached image - it only happens on the menu because the actual game doesn't use this effect). But this doesn't work on the Enterprise because the CPU timings are different from the Spectrum.
Is it even possible to have stable border effects on the Enterprise? On the Spectrum the Z80 CPU and the graphics ULA run from the same clock, so you can time the Z80 code exactly.
On the EP, the Z80 and Nick chip run on different clocks which I guess means that you can't predict the exact timings for how long the Nick chip is going to delay the Z80. Perhaps if the variation is only a few clock cycles different and this happens during the horizontal blanking then it would work. Or maybe you would have to set up Nick interrupts and use them to do the timing?...
Yes :)
yes :)
Yes, I have some stable border effect, without timing, but if you want different border effect than mine, checking Nick interrupt flag is a good idea.
You can test this just enter into the debugger of emulator:
A 1000 3E 0C LD A, 0C
A 1002 D3 BF OUT (BF), A
A 1004 F3 DI
A 1005 3E 01 LD A, 01
A 1007 D3 81 OUT (81), A
A 1009 3E 08 LD A, 08
A 100B D3 81 OUT (81), A
A 100D 3E 09 LD A, 09
A 100F D3 81 OUT (81), A
A 1011 00 NOP
A 1012 C3 05 10 JP 1005
A 1015
;1000 0023 0001 6F3E 06FF B1DF 6562 B253
Here is another:
A 1000 3E 0C LD A, 0C
A 1002 D3 BF OUT (BF), A
A 1004 F3 DI
A 1005 AF XOR A
A 1006 01 81 20 LD BC, 2081
A 1009 80 ADD A, B
A 100A ED 79 OUT (C), A
A 100C 00 NOP
A 100D C3 09 10 JP 1009
;1000 0023 0001 6F3E 06FF B1DF 6562 B253
or this:
A 1000 FB EI
A 1001 3E 0C LD A, 0C
A 1003 D3 BF OUT (BF), A
A 1005 76 HALT
A 1006 F3 DI
A 1007 3E 01 LD A, 01
A 1009 D3 81 OUT (81), A
A 100B 3E 41 LD A, 41
A 100D D3 81 OUT (81), A
A 100F 3E 09 LD A, 09
A 1011 D3 81 OUT (81), A
A 1013 3E 49 LD A, 49
A 1015 D3 81 OUT (81), A
A 1017 3E 59 LD A, 59
A 1019 D3 81 OUT (81), A
A 101B 3E 4B LD A, 4B
A 101D D3 81 OUT (81), A
A 101F 3E 5B LD A, 5B
A 1021 D3 81 OUT (81), A
A 1023 3E DB LD A, DB
A 1025 D3 81 OUT (81), A
A 1027 3E 40 LD A, 40
A 1029 D3 81 OUT (81), A
A 102B 3E 08 LD A, 08
A 102D D3 81 OUT (81), A
A 102F 3E 48 LD A, 48
A 1031 D3 81 OUT (81), A
A 1033 C3 07 10 JP 1007
A 1036
;1000 6020 2081 6F3E 06FF B1DF 6562 B253
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Yes, I have some stable border effect, without timing
Wow - thanks for these. They look really good.
Although when I tried on the emulator, the 2nd demo wasn't stable for me - not sure if I was doing something wrong... Haven't tried it on a real Enterprise though.
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Wow - thanks for these. They look really good.
Although when I tried on the emulator, the 2nd demo wasn't stable for me - not sure if I was doing something wrong... Haven't tried it on a real Enterprise though.
If you mean that it is not stable because the start position of colours can be changed at each start then it is normal. If the picture was moved then please try to run it on EP128 config on 4MHz.
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I have been asking around a bit on the OSSC forum about the different settings on the OSSC, to be sure that I am using the best settings for the output from the EP.
There I get the info that the resistors in the cable are not big enough :?: :
"According to the video out specs the sync is TTL level and the RGB signals are 4 volts. The 100 Ohm resistors are not enough. They should be at least 330 Ohm for RGB. For TTL Csync 470 Ohm is usually used. Otherwise the sync voltage will be too high for SCART and may damage the OSSC."
Link to OSSC forum (https://www.videogameperfection.com/forums/topic/sync-issue-on-enterprise-128/#post-22784)
Retrocables told me that the resistors used in the cables are as they should be according to the official EP documentation (https://www.dropbox.com/s/mlc00fbilsa7lc0/Scart%20resistors.gif?dl=0):
“The resistors value are 100ohm(in RGB signals and Sync) and 470 ohm between pin 8 and 16 for RGB activation singnal.”
I do not have any problems with a very "bright" image, but I would like to hear what people here think about the best size of the resistors in scart RGB cables? I would certainly not want to damage my OSSC ....
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Practice (http://enterprise.iko.hu/pinouts.htm) and some expert tests (https://enterpriseforever.com/hardware/resistor-values-for-scart-cable/) have shown that the Enterprise colours and sync signals could need higher resistors on some equipments, up to 330 Ohm.
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Practice (http://enterprise.iko.hu/pinouts.htm) and some expert tests (https://enterpriseforever.com/hardware/resistor-values-for-scart-cable/) have shown that the Enterprise colours and sync signals could need higher resistors on some equipments, up to 330 Ohm.
Thank you :-)
I do not have the brightness problem when I use the OSSC. BUT, if I take the scart directly to my TV/monitor (an old Samsung that has both scart and DVI and VGA) then the picture is rather bright.
I will see if changing the resistors to 220R (as suggested) will make things better.
BTW: I found a modern LCD-monitor that supports 15khz output. (http://amigax1000.blogspot.com/2017/12/acer-lcd-screen-that-supports-amiga.html) and therefore should support the standard output of the EP.
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You mean multi-sync monitors. You have this (http://15khz.wikidot.com/) list, probably not complete.
To use one of these monitors you don't need electronic adapters, only to arrange the Enterprise signals to the VGA connector.
Personally I use my Enterprise connected to a NEC Multisync 17'' monitor with sound. It has a second DVI input that I plan to use with the GFX-NINE MSX cartridge. The two inputs are switchable with a button.
What I don't know is if this monitor is also able to sync to 25KHz.
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You mean multi-sync monitors. You have this (http://15khz.wikidot.com/) list, probably not complete.
To use one of these monitors you don't need electronic adapters, only to arrange the Enterprise signals to the VGA connector.
Personally I use my Enterprise connected to a NEC Multisync 17'' monitor with sound. It has a second DVI input that I plan to use with the GFX-NINE MSX cartridge. The two inputs are switchable with a button.
What I don't know is if this monitor is also able to sync to 25KHz.
Yes. I also found that webpage along the way :-)
How is the picture quality on your NEC?
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Another alternative, get one Monitor-TV with native SCART input. Primary from LG then Samsung.
I'm using LG M2362DP.
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How is the picture quality on your NEC?
Simply perfect but, as Zozo said, a cheap second hand LCD TV with SCART input can do the same job. Better a 4:3 one. You also can use its VGA input for a PC.