X68000 HELP !

[cat9921]

HI all

great forum, Ok were to start 

I have a x68000 original model that I got from jauce.com . I have managed to get the power on thanks to this site and have a master disk to load and I have a scart adapter to try.  But I do not get a TV signal from my sharp ?

I have read a bout this

https://gamesx.com/wiki/doku.php?id=x68000:fixing_rgb_output

The problem is I am not good at electrics    I only just managed to get the power done from help by a friend. I don't know if the keyboard is working either, the keys don't light up, and obviously not being able to get a signal on the tv, not sure if it's working

So what I am asking is this is there a person in the uk that can fix this and recap as well.
Sorry for such a begging post for help but I do not know what else to do

Thanks

[SuperDeadite]

SCART adapter?  Is your moniter compatible with this?  The system outputs RGBHV at 31khz.  Your typical 15khz SCART tv isn't going to work.

[haightc]

Like superdeadite said the default resolution is closer the VGA.   The x68000 uses an odd sync timing so even then it might not work.   For example my ikegami htm-1700 would choke on the resolution.    My Megaview 29 will kind of display but the picture is fuzy.   However on the XM2950 and viewsonic GS900 the picture is fine.   Of all my professional monitor it looks best on the viewsonic.

[cat9921]

First off A big thank you for the replies . As you lot have figured I am a noob to all of this
I live in the Uk and the adapter that I mention is this one

https://www.ebay.co.uk/itm/RGB-SCART-Sharp-X68000-cable-x68k/331636530283?epid=517134266&hash=item4d3713dc6b:g:WhYAAOSwymxVO-Ep:rk:10:pf:0

So how would you go about getting the x68000 on a UK TV or monitor ?
Thanks

[skpstmgs]

PC CRT (31KHz+) - Most X68000 titles should default to 31KHz, so this is a pretty good solution and you can probably find one for cheap or even free if you check local listings. You just need to make sure you have an adapter to physically hook up the cable from the X68000 to a VGA input. 15KHz/24KHz titles obviously won't work, but only a minority of games default to these modes.

OSSC (Open Source Scan Converter)+HDMI to VGA adapter into a PC CRT will allow you to linedouble 15KHz and 24KHz video modes so they will work on a common 31KHz PC CRT. This is what I use but I also split the signal before it enters the OSSC as a way of completely bypassing any processing since it's better to use it directly for 31KHz.

XPC4 into any LCD/CRT screen that is 31KHz (640x480 and higher).

The OSSC will output the same refresh rate as the input, so plugging it into a PC LCD may or may not work. a PC CRT is a safer bet for it working. A lot of games run at around ~55Hz instead of the 60Hz that modern LCD displays expect.
XPC4 outputs a constant 60Hz which will be compatible with any modern display, but it can introduce some frame stuttering/jerkiness when scrolling, plus it adds about a frame or two of input lag (not too noticeable for most people).

I also heard of people using Amiga monitors which may support 15/24KHz, but I have zero experience with these so maybe someone else can chime in.
Another thing that is probably possible is splitting the signal into a PC CRT and a 15KHz CRT TV separately, and use whichever is required based on the game, though you'll probably have to use some powered VGA splitter and that cable you linked probably won't be of any use. I think you'd need to adapt the DB15 to VGA, split it with a VGA splitter, hook up one VGA cable into a PC CRT, then use a VGA to Scart adapter to the CRT TV. The latter will require a cable that combines the H+V sync into Composite sync.

[cat9921]

OK just thought you would all like to know, I have just tried another TV and a get a bit of a picture through, here is the screen shot

https://ibb.co/khgxNT9

The same tv is connected to the amiga 1200 and it has no problem with a display 

[haightc]

The J-RGB to SCART cable linked earlier just merge the H and V sync which can cause a lot of issues.     There should be ready made cable to convert to VGA.   It's pretty easy to make a cable yourself that is J-RGB to VGA, you can even get terminal type so you can make yourself a cable without soldering.    If your TV/monitor doesn't take VGA just use a simple VGA to HDMI transcoder.   

[cat9921]

The J-RGB to SCART cable linked earlier just merge the H and V sync which can cause a lot of issues.     There should be ready made cable to convert to VGA.   It's pretty easy to make a cable yourself that is J-RGB to VGA, you can even get terminal type so you can make yourself a cable without soldering.    If your TV/monitor doesn't take VGA just use a simple VGA to HDMI transcoder.

I ordered a scart to HDMI, Will that work as I ordered it before I saw your post ? 

[leonk]

SCART out of an X68000 is not a good idea.  I know it's been tried before (heck, I made by own cable!) but after extensive testing on my oscilloscope I can tell you that most X68K issues are due to people trying to get SCART to work! 

The frequency is out of range of SCART (31k vs 15k) and the SYNC is all wrong (SCART requires combined horizontal + vertical sync, X68K only puts them out as separate 2 signals.  Combining them together without a special circuit is dangerous).  Worst part is the levels.  Real SCART expects 75ohm 300mV peak-to-peak SYNC.  X68000 puts out 5V peak-to-peak.  Try feeding that into your XRGB mini and see how long before it blows.

[cat9921]

OK trying to get my head all around this    So if I order this

https://www.ebay.com/itm/Sharp-X68000-VGA-Cable-Converter-Adapter-RGB-Use-any-VGA-monitor-31Khz-Video-/273550325192

then I order this

https://www.ebay.com/itm/HDMI-to-VGA-converter-adapter-3-5-mm-audio-jack-full-HD-1080P-black-N3/122087176610?epid=1278897008&hash=item1c6cf679a2:rk:5:pf:0

Will That work ? If not can I have some links to what you guys recommend

Thanks

[leonk]

The first is correct.. will allow you to connect X68K to standard PC VGA port.  But second link is HDMI to VGA?!?

Your best bet is either use computer LCD screen.. or if you really want big screen TV, use OSSC to convert from VGA to HDMI.  The OSSC has the VGA port on it already.

[skpstmgs]

The HDMI to VGA converter is only useful if you want to hook up the OSSC to an analog display like a PC CRT, otherwise you just use the HDMI output, but I'm not sure how compatible the signal being output will be with modern displays.

[cat9921]

The first is correct.. will allow you to connect X68K to standard PC VGA port.  But second link is HDMI to VGA?!?

Your best bet is either use computer LCD screen.. or if you really want big screen TV, use OSSC to convert from VGA to HDMI.  The OSSC has the VGA port on it already.

Ok Thanks will order one and will let you know how it goes that ossc are not cheap  Think I try the first one just to test 

thanks again

[haightc]

You can get VGA to HDMI scart transcoders.   I think I paid $30 for mine. Just try to avoid cheap scalers.   However if your monitor accepts VGA I would just start with that.   

[hoshikawa]

You need a sharp monitor or an XPC-4, accept nothing less. it's not a cheap hobby....

[SuperDeadite]

You need a sharp monitor or an XPC-4, accept nothing less. it's not a cheap hobby....

Hell no.  29" tri-sync arcade moniter for the win

[skpstmgs]

You need a sharp monitor or an XPC-4, accept nothing less. it's not a cheap hobby....

Hell no.  29" tri-sync arcade moniter for the win

Do they make these anymore or is there anyplace that sells old stock?
Also, do they auto-switch or does it require some kind of manual switching of resolutions?

[frankmonk]

yeah, tri sync arcade or if you are lucky an nec xm29.... best options for this sweat machine

[SuperDeadite]

From what Ive heard XM29 doesnt work with 24khz.  But there are only a handful of games that need it.  As for getting a new arcade moniter.  Easy in Japan.  I think Happ has in USA.  No idea on Europe.  And of course you want an auto-sync.

[frankmonk]

The XM29 does 24khz but all other models like the xm29 plus or xp29 do not

try to get a microvitec M1438 monitor if in europe. these are the tri sync monitors I am aware of which are rather easy to obtain, especially in the UK.

[haightc]

Yep, last I checked HAPP sells them for brand new still for like $500.  A trisync arcade monitor isn't going to look as good as a professional monitor but should still be better than a consumer CRT.   Even the XM29 is a pretty big step down from from JVC pro monitors.   Some of the OEM monitors are pretty decent but not all monitors are the same.   I have sharp 606(?) which I won at online auction for 1000 yen, but it ended up costing 22,000 to ship.   It produces a pretty good image all conisdered but I probably wouldn't have gotten it knowing it had to go EMS.    If you are just doing the x68000 I might recommend doing a dual monitor setup with a professional/graphics grade CRT then having a PVM you can toggle over to when you can use 15 kHz modes.   IMO is 15kHz mode in available use it, most often it looks and runs better.