Superboard Colour RGB and composite interface

MK14HAK
Posts: 343
Joined: Wed Mar 16, 2011 1:49 am
Location: New Zealand

Superboard Colour RGB and composite interface

Post by MK14HAK » Sat Feb 23, 2019 8:29 pm

I am thinking of building this RGB colour and composite video interface for the SeriesII RevD 600 board. 9 Chips are required plus 2114 ram in free socket on the RevD. Plugs to existing socket on RevD.
How much of this could be done in PALs ?. Am I right the open collector gates would have to be separate LS03's. Can the LS157 logic be done with a PAL and are they OK at video frequencies ? The composite output should give better video than existing Superboard gate output.Bonus.

A good project for me to get back into learning Dip Trace that I started on a couple of years back, I'm also taking a look at Kicad-Dip Trace import-export options. Or should I just switch to KiCad ?

LS175 LS86 LS20 LS04 LS17 LS10 LS00 LS03 *2
630 Colour 600RevD.jpg
630 Colour 600RevD.jpg (80.14 KiB) Viewed 1487 times
600RevB:16K,2MHz,64x32,470,CEGMON
SuperKit:502,540B,542B,CEGMON, 8" and 5" FDDs
Cards:PE IO,6522 D-A-D, AY3-8910,ProgramGraphics,Color,UK101
WIP:HexDOS,FDD Emulator

MK14HAK
Posts: 343
Joined: Wed Mar 16, 2011 1:49 am
Location: New Zealand

Re: Superboard Colour RGB and composite interface

Post by MK14HAK » Wed Feb 27, 2019 1:53 am

RevD board requires 8T28 and additional 2114 RAM. Colour IF connects to J75.

But what's going on at R5,R7 and R12. I suspect they should be variable ? 220R ? 5K ?
R3,R8,R10 perhaps 4K7

It's also going to need separate HS and VS to drive PC type DVI with a differential analog chip O/P maybe. Its getting complicated.
600RevB:16K,2MHz,64x32,470,CEGMON
SuperKit:502,540B,542B,CEGMON, 8" and 5" FDDs
Cards:PE IO,6522 D-A-D, AY3-8910,ProgramGraphics,Color,UK101
WIP:HexDOS,FDD Emulator

Mark
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Joined: Tue Sep 16, 2008 6:04 am
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Re: Superboard Colour RGB and composite interface

Post by Mark » Wed Feb 27, 2019 9:29 pm

The OSI440 color mod notes described the process of connecting the RGB open collector outputs to the electron guns of a color monitor, modifying the resistors as needed!
The easiest solution would be to find an old RGB CRT that does 15Khz, but unfortunately they are rather expensive these days. (Maybe an old Sony PVM-1354Q Trinitron, or Amiga monitor?) The retro gaming guys use upscalers. Look for "Scart to HDMI NTSC/PAL" Video Converters. I'm not sure they would lock on to the signals sent by the OSI but the run less than $30. The classic arcade guys may have a preferred convertor... I had some links saved, but didn't find them quickly. Anyway, Good Luck!

Steve Gray
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Re: Superboard Colour RGB and composite interface

Post by Steve Gray » Fri Mar 01, 2019 4:47 am

Mark wrote:
Wed Feb 27, 2019 9:29 pm
The OSI440 color mod notes described the process of connecting the RGB open collector outputs to the electron guns of a color monitor, modifying the resistors as needed!
The easiest solution would be to find an old RGB CRT that does 15Khz, but unfortunately they are rather expensive these days. (Maybe an old Sony PVM-1354Q Trinitron, or Amiga monitor?) The retro gaming guys use upscalers. Look for "Scart to HDMI NTSC/PAL" Video Converters. I'm not sure they would lock on to the signals sent by the OSI but the run less than $30. The classic arcade guys may have a preferred convertor... I had some links saved, but didn't find them quickly. Anyway, Good Luck!
I'm also interested in connecting my C4P via RGB. I have several SCART TV/Monitors (like the one in my recent posts) and also several different RGB to VGA or HDMI converters (I have a couple of those $30 HDMI ones, and some GBS8200 converters). I also have Kicad and PCB layout experience. I'm willing to help.

Steve
C4P working, C1P working. 600D Replica working, C4P+D&N floppy not working. 505 board, 610 board, Mittendorf board, TOSIE hacker board need testing, PicoDOS disk untested.

MK14HAK
Posts: 343
Joined: Wed Mar 16, 2011 1:49 am
Location: New Zealand

Re: Superboard Colour RGB and composite interface

Post by MK14HAK » Fri Apr 19, 2019 8:13 am

630 Colour 600RevD
Kicad me please. RevD in colour. :mrgreen:
wrote: So, a little update. I've studied that schematic and it's definitely simple enough to copy and make a little board. I might do that, but in the mean time I've come up with a 3-chip substitute schematic that should do colour but not exactly like the OSI.

Does anyone know of some existing C1P series-2/Superboard Rev D software that uses colour?

So, basically if the 600 Rev D colour option operates the same as the 540B board then colour value 0/1 (yellow) and 14/15 (black) do not make sense. In fact there is no white colour. In a typical RGBI system 0 is black and 15 is white. The circuit I've come up with is "normal" RGBI (where I means "invert") and can be set to act like OSI (light color on darker version, or inverted) or like "normal" RGBI where you have Colour on Black or inverted (black on colour).

Walter and I are planning to breadboard the circuit soon and if it works out I'd like to make a PCB for anyone interested.

Steve
No colour software here. Only the games disks on Mark's site and the programs in C4 manual that I know of.
I'm a little confused here. Does 0/1 not give yellow char on black and black on yellow. 14/15 white on black and black on white. Giving you a white ?
Unfortunately I only have a 540A without colour.
Your SCART LCD, this has TTL RGB I presume - I understood they were analog component YPrPb or analog RGB typically on SCART. Is this an oddball?
Is your 3 chip design likely to work on a 540 mono as well Steve ? I intend having a go at the 630 and a GAL version but it will be a long term project so I will be interested in what you come up with meantime.
Mike

PS. In WinOSI I see the opposite of what the C4 manual suggests. Inverted colours (odd numbers) are giving coloured background symbol black ??
600RevB:16K,2MHz,64x32,470,CEGMON
SuperKit:502,540B,542B,CEGMON, 8" and 5" FDDs
Cards:PE IO,6522 D-A-D, AY3-8910,ProgramGraphics,Color,UK101
WIP:HexDOS,FDD Emulator

Steve Gray
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Joined: Mon Oct 06, 2008 1:54 pm
Location: Markham, Ontario, Canada
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Re: Superboard Colour RGB and composite interface

Post by Steve Gray » Fri Apr 19, 2019 3:53 pm

I have used my Sole SCART TV/monitor with SCART cables I have purchased on ebay with my Amiga, Atari ST, BBC Model B, C128 and various game consoles. It works great. It also has vga, hdmi, component, and composite. It seem to handle both TTL (5V) and analog RGB (0.75 to 1.0 V) fine.

I do not have any experience with the 540 mono board. I have the 540B with colour. The 540B has 2K video ram and 2K (nibbles) colour ram and they are split in the memory map. One line of text always takes 64 bytes in memory even in 32-column mode. So basically if you were in 64 mode and poked a character every 64 bytes you would get a vertical line of characters. If you switch to 32 column mode that vertical line is still there. The superboard Rev D however works differently. In 24 character mode each line uses 32 bytes of ram, and in 48 character mode each line takes 64 bytes of ram. So, software designed for C4P 32-column mode is not going to work on superboard rev d due to the differing amount of ram allocated to each line. And that doesn't even take into account the overscan problem.

Composite colour on the 540B is generated with an NTSC frequency clock run through a chain of inverters to tap the various clock phases. In fact OSI stole this circuit from Don Lancaster's TV Typewriter Cookbook (pg 205). The 540B also has RGB output but I don't know exactly how this works yet.

The Superboard Rev D only has RGB and Invert. It seems the 630 board tries to emulate the 540B but has no NTSC clock so I'm not sure how accurately it emulates it.

As far as I can tell both systems use the invert bit to invert the pixel colour. It appears that in normal mode you have a bright pixels for "1" bits and darker pixels of the same colour for "0" bits. When the invert bit is "1" you get dark pixels on a bright background.

On 540B composite , when colour bits are "0000" you get yellow on dark yellow (or very close to black). There is no "white". There is a "black" and also a "no colour" (according to the manual):
DSC08433 (crop).jpg
DSC08433 (crop).jpg (122.63 KiB) Viewed 1058 times
As for the 630 the circuit is a bit convoluted but it seems to have circuitry to detect "0000" and change it to yellow. There are resistors to modify the output levels. I don't pretend to be able to follow it right now and I've never seen a 630 board or it's output, so it's hard to know for sure how things work.
Here is my current circuit. I tried to give the option to simulate the OSI way, or normal RGB way. It currently does not support monochrome-only output (ie: when colour is NOT enabled via the control register):
Attachments
OSI-600D-colour.pdf
(64.19 KiB) Downloaded 64 times
Last edited by Steve Gray on Fri Apr 19, 2019 4:16 pm, edited 1 time in total.
C4P working, C1P working. 600D Replica working, C4P+D&N floppy not working. 505 board, 610 board, Mittendorf board, TOSIE hacker board need testing, PicoDOS disk untested.

Steve Gray
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Joined: Mon Oct 06, 2008 1:54 pm
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Re: Superboard Colour RGB and composite interface

Post by Steve Gray » Fri Apr 19, 2019 4:14 pm

Also, correct me if I'm wrong but won't the 630 composite output also be in monochrome? I don't see how it could be colour. It does seem to handle the inverse line so it's still a bit of improvement over the 600 composite.

Steve
C4P working, C1P working. 600D Replica working, C4P+D&N floppy not working. 505 board, 610 board, Mittendorf board, TOSIE hacker board need testing, PicoDOS disk untested.

MK14HAK
Posts: 343
Joined: Wed Mar 16, 2011 1:49 am
Location: New Zealand

Re: Superboard Colour RGB and composite interface

Post by MK14HAK » Sat Apr 20, 2019 6:12 am

Yes the composite output is NOT ! colour on 630D. Are you going to add to your design ?
I don't get how the 540B does the intensity modulation. Is it pixel on-time rather than RGB levels perhaps?

What does this look like on 540B ? Compare to WinOSI ?
C4 Color test.BAS
(562 Bytes) Downloaded 59 times
Last edited by MK14HAK on Sat Apr 20, 2019 9:59 pm, edited 2 times in total.
600RevB:16K,2MHz,64x32,470,CEGMON
SuperKit:502,540B,542B,CEGMON, 8" and 5" FDDs
Cards:PE IO,6522 D-A-D, AY3-8910,ProgramGraphics,Color,UK101
WIP:HexDOS,FDD Emulator

Steve Gray
Posts: 279
Joined: Mon Oct 06, 2008 1:54 pm
Location: Markham, Ontario, Canada
Contact:

Re: Superboard Colour RGB and composite interface

Post by Steve Gray » Sat Apr 20, 2019 3:03 pm

I have an updated schematic that fixes some things, adds the monochrome-only display to the RGB output, and has some extra info. The circuit is now 4 chips...

Once we get to RGB we can then add an MC1377 chip to generate colour composite. Walter and I will try to breadboard that too.

Here is the latest version:
OSI-600D-colour.pdf
(83.71 KiB) Downloaded 67 times
Steve
C4P working, C1P working. 600D Replica working, C4P+D&N floppy not working. 505 board, 610 board, Mittendorf board, TOSIE hacker board need testing, PicoDOS disk untested.

MK14HAK
Posts: 343
Joined: Wed Mar 16, 2011 1:49 am
Location: New Zealand

Re: Superboard Colour RGB and composite interface

Post by MK14HAK » Sun Apr 21, 2019 9:18 am

Looking good with the MC1377. Is Canada NTSC or PAL by the way?
Does the C4 540B video look better on composite for graphics compared to RGB ?
That cookbook is a gem ! I hope I can encourage one of my boys to read,I'm teaching them electronics and programming on my SKIT502 having enticed them with a boot disk that launches 8 games from a menu and quits to ROM BASIC with an editor an Toolkit installed. A reboot auto runs any program already in memory. (Things have to be simple to keep them interested.)Will be great to have them adding colour and sound to existing programs.

I've been looking at what additions would be required to make your design work with a RevB and 540 mono. Maybe add 1*2114 and plug into one existing 2114 VRAM socket and a link to address decode...

RevB:

8T28
2114

VID U70-2 existing
CHLD decode *
COLEN decode *
CSYNC U70-11 existing
BLANK U62-10 (DB) existing
SVID U70-3 existing



540 mono:

8T28
2 * 2114
LS00
LS86

VID existing
CHLD decode *
COLEN decode *
CSYNC U4D-6 existing
BLANK U3G-12 existing
SVID non existing

540 mono looks like would need own dedicated pcb but I think RevB would be doable with additions to your evolving design?

Just realised I have a 540B-1 mono not a 540A. Bye the way, is there a component layout pic of the 540B-1. Anyone ??
600RevB:16K,2MHz,64x32,470,CEGMON
SuperKit:502,540B,542B,CEGMON, 8" and 5" FDDs
Cards:PE IO,6522 D-A-D, AY3-8910,ProgramGraphics,Color,UK101
WIP:HexDOS,FDD Emulator

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