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Olivetti M19

Jan de Lange said:
Question: does the M24 monitor have the same slow phosphor as the M19? Or is it totally incompatible?
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DSM1912 has P39 type coating, which is also used by IBM 5151 and a plethora of other MDA monitors.
I cannot find what type of phosphor M24 monitors have in any of my documentation.

I think I get why you're asking, and my answer would be yes - the dithering should work on M24 monitors too. It actually works on M24 monitors, with EGC card and custom programming one can send out more than 16 colours to DSM2412/C as a feature. In some other thread there was a discussion and a question was raised how much would refresh rate suffer eg how much would monitor flicker showing such a mode, as there were no documented examples found. But it is indeed a documented feature in the AT&T DEB development manual. That is for colour screen I see no functional difference for mono screen as far as dithering capability is concerned, it can only be better as the green phosphor should have more persistence than whatever RGB coating used.

Then again this doesn't matter much, as 1ST1 says these are high frequency screens and M19 signal is out of bounds.

Jan de Lange said:
I think monochrome is more interesting.
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Hunt for MDA/Hercules monitors, not much of them but https://www.ebay.de/itm/206226453480 on bid and still in cheap realms
 
The only Olivetti PC that can connect such a screen is the M19 which is the topic of this thread :)
 
Zare said:
I think I get why you're asking, and my answer would be yes - the dithering should work on M24 monitors too.
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No. The M24 videofrequency is tooo fast for M19 monitor, and that's valid for any text and graphics mode of M24. And M19 video signal is tooo slow for M24 monitor. M19 video is below of CGA standard, means, slower than 15kHz. Doesn't care if you compare the monochrome MDA-alike monitors or color monitors for M19 and M24. The M19 was made for lowcost with a graphics card which supports very cheap lowcost monitor frequency, with special phospor coating which lightens very long to hide the low refresh rate, otherwise it would flicker. And M24 video timing is beyond standard-CGA, so even a normal fixed frequency CGA monitor won't work on M24, so here you need the original monitor or something multisyncing like NEC, TVM, or modern TFT from that 15khz list which is flexible enough to support something like 24khz as well...

What I never have seen if someone tried to get a real MDA monitor on M24. Maybe it is possible, you need to get the M24 to make the MDA alike video signal, but I have doubts if a standard MDA monitor would be fast enough for M24 video frequency. To switch the M24 to monochrome output you need to let pin 2 and 10 of the connector open while for a color monitor you need to ground both. This pin changes the card's behaviour in some matters, not only it outputs a monochrome (dithered) videosignal, but it also changes some text attribute behaviour.

But all of this really should be discussed in a extra thread, M24 not equal to M19, different model, different specs, different technology, different target customer (low cost versus "better than IBM"). I don't understand that no moderator reacts here, also not on the report button for a separation of topic. Maybe more peoples should report the seapration of topics.
 
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No no I didn't mean connecting M19 dithered signal to it, but generally the monitor should accept a dithered signal of appropriate frequency, like in the custom colour mode on the DEB card.
 
1ST1 said:
What I never have seen if someone tried to get a real MDA monitor on M24. Maybe it is possible, you need to get the M24 to make the MDA alike video signal, but I have doubts if a standard MDA monitor would be fast enough for M24 video frequency. To switch the M24 to monochrome output you need to let pin 2 and 10 of the connector open while for a color monitor you need to ground both. This pin changes the card's behaviour in some matters, not only it outputs a monochrome (dithered) videosignal, but it also changes some text attribute behaviour.

But all of this really should be discussed in a extra thread, M24 not equal to M19, different model, different specs, different technology, different target customer (low cost versus "better than IBM"). I don't understand that no moderator reacts here, also not on the report button for a separation of topic. Maybe more peoples should report the seapration of topics.
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I am planning to try an MDA CRT monitor hopefully within several weeks (still too busy with other tasks) with the remnants from M24 I acquired.

Feel free to create or point to M24 topic.
 
george said:
Feel free to create or point to M24 topic.
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I am not a moderator here, otherwise I would cut out and separate that M24 discussion in a new thread. And I don't want to be moderator, not here and anywhere else, but I ask myself, where they are, and why they don't do anything in such matter, also like 486/pentium topics moving away from XT/286 subforum. That never happens. But this is again offtopic from offtopic.
 
Different people may put different order/choose different subsets in one and the same information. By the way would you help me remember what was the model of this 286 CPU based Olivetti PC that I used to have for a while. The monitor had higher scan rate than the CGA but graphics card was recognized by most of the PC software as CGA.
 
I can display the M19 mono signal on VGA and also on the Macintosh M1212 using a reconfigured Mceblaster (Pico). That gives flicker in the grey scales as a normal LED panel and the M1212 are too fast (not slow enough). So now I am working on the software time integration, but that's rather complex with 2 video buffers and 3 state machines at 270 MHz fighting for bus access and bandwidth. A slow phosphor VGA monitor would make the integration step not necessary (easy way out).
 
"not a slow phosphor VGA monitor", because every VGA monitor will be too fast, and the digital TTL signal can't be feed directly into analoque VGA input. But the original monitor Olivetti DSM-1912 would make it easy. Recently I got a 3rd one cheap as just 30 euros , so now all my three M19 have original monitor.
 
I wouldn't mind getting another one, have 2 but my original monitor has lost brightness. I actually never seen one on ebay sale. Do you have a list of sites where you source them? I understand if your sources are private :)

@george how do you intend to make M24 display 18 kHz frequency?

@Jan de Lange do you mind shooting a quick video how the 16-color bar looks like on your setup?
 
I too am in the market for a "new" M19 monitor. That's why started the VGA route. @Zare At present I am working on other things, but I will create a capture when I have the screen up and connected. My pico signal goes into VGA and M1212 via a resistor DAC. Works fine.
 
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So here it is. Now I have a ETV 500 system. The ET 109 is just added as a dummy to ilustrate how a complete ETV 500 system looked like. The ET 109 typewriter has no interface option but my similar looking ET 116 with the serial interface is stored and in front is a stack of other machines, no way to reach it at the moment... The keyboard is from ETV 260. ETV 500 originally has been delivered in two configurations: a) system plus ET 112/116 typewriter, used as keyboard and printer, b) system plus ETV 500 keyboard plus DY-450/800 daisywheel printer. I will not try it during the next weeks, no time...

Later, first step will be to attach an ET 2x00 typewriter with ETV kit to ETV 500 keyboard connector and boot it with the ETV 2900 diskette, this should work immediatelly. Then creating a diskette from ETV 260 master, removing the ETV 260 drivers, put german keyboard driver and attach the DY-450/800, this also should work immediatelly. Then the challenge, attach the ET 116 and try if it would type and print after starting CTTY COM1. But I think the standard ET 116 with the standard LCU 116 has no cursor keys, a ET 112/116 with ETV kit would be required. Maybe my ET 225 with ETV-300 kit works??? That would be wonderfull.
 
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