X68000 & Fm Towns monitor

[yirmiahu72]

Is it possible to use a Towns monitor with the x68000? I know according to the wiki on here the pinouts are similar although not as close as the PC 9801.

Also what about the keyboard? Are the connectors the same for the two?

[SuperDeadite]

Monitor is possible but you need a proper adapter.  Do NOT directly connect an X68K to a Towns monitor with a straight cable, it can fry the X68's video board.

Keyboard is completely different, not compatible at all.

[yirmiahu72]

Thanks.

What sort of adapter?

[caius]

Thanks.

What sort of adapter?

Hi,
basically pinout of A/V for mFM-TOWNS and X68000 are very similar with some differences as you can see:

http://www.gamesx.com/wiki/doku.php?id=av:japanese_rgb-15

The dangerous difference is that in  X6800  +5V is present on pin 7 while FM-TOWNS  it's on PIN9.

[RetroRepair]

Well I finally got my FM Towns II working but having an issue with connecting up the X68000. I have RGB etc connected ok and Ys connected pin 7 on the x68k to pin 9 on the FM Towns monitor input but no picture on the screen.

Am I missing something or is my video output on the x68k fried? I've not seen it working on any monitor yet.

[caius]

I would not connect pin7 from 68000.I can say I have a unique cable for FM-TOWNS, X68000 and PC-9821 that works perfecly with my Microvitec M1438S monitor.

[eidis]

 Hi RetroRepair !

All you need for an image to be displayed is RED, GREEN, BLUE, H-Sync, V-Synch and GROUND. Try disconnecting YS and see if it helps. You might also try connecting it to a PC monitor.

X68000 to PC Monitor Cable/Adapter
http://gamesx.com/wiki/doku.php?id=x68000:x68000_to_pc_monitor_cable

In case if that does not help there is a high probability that the sync inverter is broken and needs to be replaced.

Fixing RGB output
http://gamesx.com/wiki/doku.php?id=x68000:fixing_rgb_output

Keep the scene alive !
Eidis

[RetroRepair]

Hmm well I disconnected the Ys so only R,G,B,HS,VS and GND were connected and still no picture. I have an X68000 Compact here to repair and nothing from that either. I should be outputting a video signal as it's looking for a disk.

The internal FM Towns image is working fine so not sure what to make of it.

It's this machine:

http://blogimg.goo.ne.jp/user_image/1c/0a/fa78c32b76c04296be17f90a9d08a363.jpg

[RetroRepair]

I'm wondering if av control or mode need to be present for it to switch? Does anyone know what the towns monitor expects to see on these pins?

[RetroRepair]

Ok well it seems the FM Towns wanted C-Sync on pin 7 (FM Towns monitor side) so I tied both syncs together and presto, up it came!

Really a sync combining circuit should be used but it seems just connecting V and H sync together does work ok.

[caius]

Ok well it seems the FM Towns wanted C-Sync on pin 7 (FM Towns monitor side) so I tied both syncs together and presto, up it came!

Really a sync combining circuit should be used but it seems just connecting V and H sync together does work ok.

That is not normal, i think your FM-TOWNS monitor is faulty since it must accept and works also with separate syncronisms.

[RetroRepair]

This website was what made me think of trying it:

https://translate.google.com/translate?hl=en&sl=ja&tl=en&u=http%3A%2F%2Fhp.vector.co.jp%2Fauthors%2FVA018718%2Ftowns%2Findex_tt.htm


I can't see how the sync lines are wrong, maybe if you use H + V sync you need to be using a computer than can give it the dot clock/AV control/mode signals it expects?

[caius]

Maybe you refers to this diagram for connecting a normal PC to a FM-TOWNS monitor (it uses a AND gate to generate the CSYNC):

https://translate.google.com/translate?hl=en&sl=ja&tl=en&u=http%3A%2F%2Fhp.vector.co.jp%2Fauthors%2FVA018718%2Ftowns%2Findex_tt.htm

Anyway we don't know the specs of your FM-TOWNS monitor, probably it can accept only composite SYNC.

[RetroRepair]

It does seem that way. Maybe H+V sync is inverted on Towns monitors so only C sync from other devices works?