The hidden 640x400 graphics mode on the QX-16

[vprada]

Thanks everybody for the guidance. I did try several apps, but the only one I could install on a floppy for testing was PCPaintBrush and indeed I was able to get a 640x400 resolution using the ATT video driver !!! this is a huge an interesting development.

I did create a little resident program I named QX16M24 which basically will implement the AX,0040 INT 10 call that enables the 640x400 video resolution in the M24 video card. The PCPaintBrush is actually making that BIOS call to force the machine to enter 640x400. After that the program renders at 640x400. Unfortunately I don't have a serial mouse to test as input device, so I could not load any drawings that would make the resolution difference more evident than what you may see in the two screenshots. (the mousek.exe that emulates a mouse is not working correctly for me)

So this experiment proves than the QX-11 & QX-16 CGA emulation cards use the same VRAM interlace mapping than the Olivetti M19/M24 and ATT Machines and take advantage of the full 32K of VRAM to reach a 640x400 monochrome resolution. I will need to test what possibilities exists for color rendering. Documentation says the QX-16 will do 16 colors at 160x100 but I will need to test that.

Can you mention any other business program that would take advantage of the 640x400 resolution on the ATT / Olivetti PCs ?

 

[Zare]

Can you mention any other business program that would take advantage of the 640x400 resolution on the ATT / Olivetti PCs ?

Well I do remember as a child visiting parents friends and killing time at their M24, which was a double floppy system.
One floppy was for boot, the other had AutoCAD.

For something else via floppies, I need to check the sizes, perhaps GEM+io/msdos/command would fit on a single 360kb system floppy, and then you can run several of productivity applications for GEM from 2nd floppy, supposedly. I think GEM and those apps are early enough to be small enough.

But as I google for qx-16 motherboard pictures I find some some 8 bit ISA lo profile expansion cards, do you have ISA slots in there?
If you do, I would strongly suggest getting a low profile XTIDE CF adapter.

Also, I know nothing of this computer, are you certain it cannot go over 4.77 MHz?

 

[Zare]

Unfortunately I don't have a serial mouse to test as input device, so I could not load any drawings that would make the resolution difference more evident than what you may see in the two screenshots.

Seek the mouse driver for M24 mouse, I will try to locate it later.
M24 mouse is a special thing, that is connected through the keyboard, and it should work (the driver) just by using the numpad cursors of a generic keyboard.

But if you just want to verify, I can say with 99.8% certainty that is 640x400 picture. Menu font, and the fill patterns give it up cleanly.

 

[vprada]

Well I do remember as a child visiting parents friends and killing time at their M24, which was a double floppy system.
One floppy was for boot, the other had AutoCAD.

For something else via floppies, I need to check the sizes, perhaps GEM+io/msdos/command would fit on a single 360kb system floppy, and then you can run several of productivity applications for GEM from 2nd floppy, supposedly. I think GEM and those apps are early enough to be small enough.

But as I google for qx-16 motherboard pictures I find some some 8 bit ISA lo profile expansion cards, do you have ISA slots in there?
If you do, I would strongly suggest getting a low profile XTIDE CF adapter.

Also, I know nothing of this computer, are you certain it cannot go over 4.77 MHz?

The expansion slots on the qx-16 are not isa, but something epson propietary... I know there is a cfcard HD you could adapt to the qx16, but I havent try it. The qx-16 runs at 5.33mhz and I havent heard anybody trying to run it at a higher speed. You could probably change the crystal and adjust the BIOS to make it faster ,but that will require lots of elbow grease.

the QX-11 also uses a propietary expansion bus that doesn't even have all the signals an Isa card requires. The Qx-11 runs at 4.92 and Im pretty sure you can't change that.

The Qx-11 have custom epson chips that implement the interrupt controller, serial controller, diak controller,etc.. Im pretty sure that changing the crystal will break other timings and will skew the different clocks (like the keyboard serial clock or the serial port speed that are already programmed to split the crystal this or that many times)

Im working on a custom card to emulate the propietary epson HD in my qx-11 though... thats another project I will sure at the right time...

Thanks again for the guidance...I will try to test more software and post the results here

 

[Eudimorphodon]

Unfortunately I don't have a serial mouse to test as input device, so I could not load any drawings that would make the resolution difference more evident than what you may see in the two screenshots.

Oh, believe me, I could tell just by looking at the 640x400 shot on its own.

(I spent soooo much time in PC Paintbrush on the CGA XT when I was young, so it was easy for me to tell it's using the higher-res font for the text bar.. and of course the halftone hash is made up of nearly symmetrical squares instead of rectangles.. I would have killed for double the vertical resolution like that.)

I will need to test what possibilities exists for color rendering. Documentation says the QX-16 will do 16 colors at 160x100 but I will need to test that.

FWIW, it might not be referring to a "real" graphics mode, it might just mean the same 160x100 hacked text mode that CGA supports. (As used in games like Round42 and Paku Paku.) I am curious if those games would *run* on the QX-16? There's no BIOS support for that mode, on CGA you have to get it by reprogramming the 6845 accordingly, so unless the QX-16 has something akin to the m24's "scrambler" you would probably need to patch the programs accordingly?

For something else via floppies, I need to check the sizes, perhaps GEM+io/msdos/command would fit on a single 360kb system floppy, and then you can run several of productivity applications for GEM from 2nd floppy, supposedly. I think GEM and those apps are early enough to be small enough.

It's possible to run quite a few GEM programs from floppy disks, even some pretty big ones like ancient versions of Publish-It!, but it's pretty painful. For just launching little things like early versions of GEM Paint/Write/etc. you're fine, and I think even GEM 1.x might have support for AT&T graphics.

 

[vprada]

So EPSON released the QX-11 as an msdos compatible machine but I was not 100% IBM compatible. The QX-11 uses a propietary video chip that was capable of doing 640x400 monochrome and 8 colors RGB 640x200. I creates a custom sierra driver for the native video chip and the color render looks awesome...So I understand what you mean when you say "I would have killed for something like that" ...

I wrote about the color mode of the qx-11 in another post.

sq3 color

To make the QX-11 more IBM compatible, EPSON released an optional IBM CGA card for the QX-11. It is 40 years later that I realize that IBM card is compatibles with the olivetti design (and probably others)

EPSON realized that been just msdos compatible wasnt enough, and they made the QX-16 more hardware compatible with IBM and the "optional" CGA card became standard on the QX-16... both cards (the qx11 and the qx16 versions) have the same exact hardware and behave the same on both machines (though on the qx11 you have to activate the card via a driver loaded on config.sys , the qx16 BIOS activates the card automatically)

 

[Zare]

The expansion slots on the qx-16 are not isa, but something epson propietary... I know there is a cfcard HD you could adapt to the qx16, but I havent try it. The qx-16 runs at 5.33mhz and I havent heard anybody trying to run it at a higher speed. You could probably change the crystal and adjust the BIOS to make it faster ,but that will require lots of elbow grease.

Cf card is a blessing, you get native HDD and easy transfer method, cheaply.
5.33 MHz, well if you put a 8 MHz rated V20 in there that's still some good boost over the 4.77 MHz IBM PC reference.
At this point I think storage is the limiter to what you can do with the machine, even at that slower frequency there is still a lot of usable software to run.

FWIW, it might not be referring to a "real" graphics mode, it might just mean the same 160x100 hacked text mode that CGA supports. (As used in games like Round42 and Paku Paku.) I am curious if those games would *run* on the QX-16? There's no BIOS support for that mode, on CGA you have to get it by reprogramming the 6845 accordingly, so unless the QX-16 has something akin to the m24's "scrambler" you would probably need to patch the programs accordingly?

It looks like on this Epson machine CRTC is freely programmed, and I haven't picked up what is the exact monitor and video signal of it?

In any case, if it is not a CGA 15 kHz signal the CRTC values will differ.

 

[vprada]

Cf card is a blessing, you get native HDD and easy transfer method, cheaply.
5.33 MHz, well if you put a 8 MHz rated V20 in there that's still some good boost over the 4.77 MHz IBM PC reference.
At this point I think storage is the limiter to what you can do with the machine, even at that slower frequency there is still a lot of usable software to run.



It looks like on this Epson machine CRTC is freely programmed, and I haven't picked up what is the exact monitor and video signal of it?

In any case, if it is not a CGA 15 kHz signal the CRTC values will differ.

On the EPSON high resolution monitor the horiz sync is 18.87 and the vertical sync is odd 45.36

 

[brijohn]

The end result is a working custom QX-16 SCI driver that converts Sierra’s 320×200 framebuffer into a dithered 640×400 monochrome display. This appears to be a real native capability of the QX-16 hardware that was not normally exposed through its standard BIOS modes.

@vprada This is pretty cool, have you posted the QX-16 version of the driver? i only said the QX-11 version in your repos.

 

[vprada]

@vprada This is pretty cool, have you posted the QX-16 version of the driver? i only said the QX-11 version in your repos.

I just uploaded the QX-16 version of the driver in my QX-16 repo
To actually play the game you will also need a keyboard driver for the QX-16. The binary for the QX-16 keyboard driver is also in the repo.

 

[vprada]

An additional update on this. I was also able to run GEM 3.0 on the QX-16 using the ATT/aolivetti driver. Monochrome at 640x400.