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New Hardware: Atari 400/800 Super Color CPU Card


tf_hh

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Hi,

 

some years ago I gave a promise to an ABBUC member to make a video-out solution for his Atari 400 without the need of changing parts, scratching conducting paths or any other destructive mod to his Atari 400. He´s a real "hardcore" collector with no way in give-and-take regarding this point.

 

After tinkering around with an "add-on" PCB for the GTIA socket I failed, because there´s not enough space. Of course - from a collector´s view - it´s a No-Go to remove the metal cabinet, so I decide to create a complete new CPU board with the needed components directly on it.

 

I´ve reached the goal by 99%. A very little bit of soldering is required and the need to drill one hole into the metal assembly - the shielded video cable needs a place to break out, there´s no way else than making a new 5 mm hole somehwere in the upper part of the metal assembly.

 

So here´s my solution: The Super Color CPU Card for Atari 400 and Atari 800 systems

 

post-15670-0-55387200-1483453652_thumb.jpg

This PCB is a complete replacement for the original CPU card in any Atari 400 or 800 using PAL or NTSC. This PCB works NOT with SECAM. You are able to use both CPU-types found in the Atari 400 and Atari 800 series, the standard 6502B MOS CPU (without HALT signal) and the Atari-specialized version 6502C, also called "Sally". Chips (CPU, ANTIC and CTIA or GTIA) are not included and must be pulled of the built-in Atari CPU card. But they are always in sockets, so it´s easy.

 

Circuitry on this PCB is nearly 100% the same like at the genuine Atari CPU card with some changes to make it possible to use both CPU types. You only need to set five jumpers to select the desired CPU type. Addiitonal the PAL color clock generation circuit is onboard for PAL systems. There´s a seperate jumper to select PAL or NTSC - this jumper connects the GTIA "PALC" pin to either the output of the PAL color clock generator or directly to 3,57 MHz system clock (NTSC). Only for clarifying this: You can´t just switch the jumper and make a NTSC system to a PAL computer or vice versa. At least you´ve to change ANTIC, GTIA and of course the system clock crystal at the mainboard ;)

 

At least a third jumper block (not existing an the prototype shown on the picture above) enables/disables the 75 Ohm termination resistors for Luma, Chrominance or CVBS output. This setting must be tested depending on the connected monitor or television - sometimes the picture quality is better with, sometimes without termination resistors.

 

The video out solution is based on the Atari 800 XL video circuitry without mixing Luma and Chroma together. Of course the well-known mods are already integrated. The final signals are amplified and filtered by the Fairchild FMS6410 VideoAmp. This chip also generates the CVBS signal. So you can use either S-Video (Y/C) for best picture quality or CVBS for common monitors and televisions which doesn´t accept S-Video (Y/C) input.

 

Please notice: This video solution can´t performing magic. I test it on different computer monitors and televisions. The best performance - as ever in every setting with old computers - will be shown on CRT (tube) monitors or televisions. Of course for Atari 400 owners EVERYTHING is better than the antenna (RF) output, but don´t expect a higher quality than the regular Atari 800 S-video output. It might be better, but I can´t promise. That´s impossible by the dozens of different monitors, cables, T.V. systems and so on.

 

Scope of delivery

  • One PCB "Super Color CPU Card" for Atari 400 or Atari 800 computers, capable using 6502B or 6502C CPU, runs on PAL or NTSC systems
  • A manual (illustrated installation instructions) in german and english (sent by email with shipping out notice)
  • One DIN connector 5 pin to lead out the video signals (optional for Atari 800 users)
  • approx 50 cm shielded cable for video out
  • approx 50 cm shielded cable for internal audio connection (optional for Atari 800 users)

I offer two versions of the PCB

  • "Standard" = Full populated (except Atari custom chips) PCB, standard HASL surface (as shown in the picture above)
  • "Gold" = Full populated (except Atari custom chips) PCB, gold-finished (ENIG) surface (like my Sys-Check and many other solutions)

The ENIG (gold-finished) surface is more rugged against rust and fouling. Because the naked PCB price doubles when choosing ENIG at this board size, I offer two versions.

 

Prices

  • One "Standard" PCB = 48 Euros each
  • One "Gold" PCB = 59 Euros each
  • Registered and insured shipping 1 or 2 piece(s) worldwide = 9 Euros
  • Registered and insured shipping 3 or 4 pieces worldwide = 12 Euros
  • More than 4 pieces or specialized = please ask

Info: After some bad experiences with some postal services I only ship insured now.

 

Time schedule

  • I will collect orders and payments until the end of January, the 22.th 2017 (GMT)
  • At the end of January I will order the parts and PCBs
  • Assembling and shipping out can take up to 6 weeks, because there´s no holidays for me, assembling will be done in my spare time
  • Depending on shipping time you will get your PCB(s) in March or April 2017 - This is the worst case, but I won´t promise things I can´t realize. So this is a safe suggestion.
  • First payment, first serve: I can´t make all PCBs at one time, so small batches will be made. Date & Time of cleared payment sets the order of shipping out

Please sent me a PM (personal message) or leave a post in this thread. You will get an answer soon.

 

Practical hints for Atari 400 users

 

The Atari 400 hasn´t any S-Video/CVBS output and no standard monitor jack, just an antenna (RF) cable. This cable is replaceable, so the best way is to remove the whole cable. You can use the hole in the case where the antenna cable was now for the new video out cable. At the end a standard DIN 5 pin connector coupling is applied. You can use ANY standard CVBS or S-Video cable made for any Atari XL or XE (or the Atari 800) to connect your Atari 400 to a monitor or television. The sound signal must be clamped from the main PCB. Nothing is destructive, only two solder drops at the mainboard of your Atari 400 must be made and one hole with ~5 mm diameter must be drilled in the metal cage for leading the video cable out.

 

Practical hints for Atari 800 users

 

Remark: The Atari 800 has already a quite good video output (S-Video). The CVBS output ranges something in the middle of existing video solutions. The need of my Super Color CPU card isn´t really mandatory for an Atari 800 owner, but it CAN improve video quality. Of course without any promises. I repeat that to make this point of view clear for all interests.

 

The first option is to go ahead like the Atari 400 user. Replace the antenna cable with the new video cable. The existing monitor connector is always out of function when replacing the Atari CPU card with my Super Color CPU Card.

 

Second option for Atari 800 users is to use the existing monitor jack with the new Chroma, Luma and CVBS signal. For this purpose the best way is to bend away the three connections from the mainboard to the power-PCB transmitting these three signals. This is reversible, non-destructive and needs only four additional drops of solder at the monitor jack.

 

The manual will show how to do and also point at the junctions where to grab the audio signal, too. If you want, the external monitor DIN 5 pin coupling connector is already soldered. Leave your wish with your order, otherwise I will ask when confiming your payment.

 

Any questions? Feel free to ask :thumbsup:

 

Jurgen

Edited by tf_hh
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Interesting. I keep thinking that a custom CPU card for the 800 with an integrated VBXE would be something that's totally worth it.

 

Yes, indeed. When I draw the first schematics for this card, I planned to try to make it work together with an VBXE. Technically I was sure to found a solution creating the EXTSEL and CASINH signals needed by VBXE. Some mods to the 800 mainboard and the personality mainboards should have be done.

 

But I discard this in the further development due to the following:

 

- The VBXE PCB won´t fit together with the CPU card in the metal assembly of the 800 computer

- For the 400 it´s totally impossible without huge changes to the main PCB

- ... most significant reason: VBXE can´t be used really useful with an 400/800 operating system (see below)

 

VBXE would work technically flawless with an old 400/800 operating system, but most of the software not. The modern type of memory expansions using PORTB ($D301) can´t used on a 400/800 PCBs without heavy mods. To make VBXE work fine, also a new personality board must be created or an Incognito must be present.

 

Maybe there are 1, 2 users out there who would purchase something like this... but spending nearly 300 bucks (all together) to make an Atari 800 work like a modded 800 XL for half the price... I think this wouldn´t be a burner :)

 

Jurgen

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I keep meaning to fit a VBXE inside my Incognito 800 (which is absolutely doable using a lot of wires) but the inability to make it look really neat puts me off. Definitely a CPU card with integral VBXE would be the way to go, but despite the notion that this would be a red hot product for Incognito owners, I have to wonder how well it would actually sell.

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Question, Have you tried your card with Incognito?

 

Yes, I´ve tested it and it works flawless.

 

I forget to mention in my 1st post: On the backside of the PCB (where no components are placed) there are two solder pads for "IRQ" and "HALT", the two signals which must be grabbed from the CPU card for Incognito.

 

Jurgen

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Yes, I´ve tested it and it works flawless.

 

I forget to mention in my 1st post: On the backside of the PCB (where no components are placed) there are two solder pads for "IRQ" and "HALT", the two signals which must be grabbed from the CPU card for Incognito.

 

Jurgen

Shut up and take my money. One Gold for me. (800)

Edited by skr
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Yes, I´ve tested it and it works flawless.

 

I forget to mention in my 1st post: On the backside of the PCB (where no components are placed) there are two solder pads for "IRQ" and "HALT", the two signals which must be grabbed from the CPU card for Incognito.

 

Jurgen

 

Yeah, Better put me down for one. I guess the Gold one. NTSC/800

 

Followup, would it be feasible to add a pcb header pin to those two solder points?

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I keep meaning to fit a VBXE inside my Incognito 800 (which is absolutely doable using a lot of wires) but the inability to make it look really neat puts me off. Definitely a CPU card with integral VBXE would be the way to go, but despite the notion that this would be a red hot product for Incognito owners, I have to wonder how well it would actually sell.

 

I think a CPU card with VBXE and an accelerated 65816 with linear RAM would appeal to most (if not all) Incognito owners. If such a card were to hit the market, it may cause enough excitement to get Incognitos back in production :)

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I keep meaning to fit a VBXE inside my Incognito 800 (which is absolutely doable using a lot of wires) but the inability to make it look really neat puts me off. Definitely a CPU card with integral VBXE would be the way to go, but despite the notion that this would be a red hot product for Incognito owners, I have to wonder how well it would actually sell.

Yeah, electrically it seem fairly straight forward -- but it's a physical nightmare.

 

 

 

I think a CPU card with VBXE and an accelerated 65816 with linear RAM would appeal to most (if not all) Incognito owners. If such a card were to hit the market, it may cause enough excitement to get Incognitos back in production :)

 

I'm not sure a 65816 holds much appeal to me, mostly because I'm not sure what I'd do with it...but yeah, something like this could be the missing link for 800 owners. Maybe we should stop crowding this thread and start a new one to gauge interest.

 

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I am very interested in one GOLD populated board too.

 

Could you please explain the Sound solution for Atari 400 a bit more?

I now added a STEREO board in the 400 to have Sound out. I did not understand how to get sound-out without this stupid STEREO board solution ;)

 

thanks

Marius

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Hi,

 

I set up a order list where every order and payment status is tracked. Will keep it up to date every 24h once or more until 01/22.

 

View list here: http://www.van-radecke.de/SuperColorCPUCard/SCCC_order.txt

 

If anything is wrong at the order list, please contact me. Thanks!

 

Jurgen

Edited by tf_hh
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Oh no! _NOW_ you come out with this great shit, just two weeks after I finished my Atari 400 video solution with this mod here:

http://electronicsentimentalities.com/5200InstallInstructions.html

So, I think it's too late for me now.

 

Some annotations:

- I made the mod without any case modifications. I used the hole for the antenna cable for a shielded 50cm cable with a standard Atari DIN connector.

- No need to drill a hole in the metal IMHO cause there already is one in front of the color potentiometer. Why not use it?

- I'd think it's a good idea to not forget the "Audio in" from the SIO-Port. It should be mixed with the pokey audio signal somehow to be compatible with all Cassette tapes.

- The Atari 800's standard S-Video out is really great. By far the best of all Ataris. I normally would not recommend any mod for this. Composite video out could be a little bit better, who knows?

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Could you please explain the Sound solution for Atari 400 a bit more?

I now added a STEREO board in the 400 to have Sound out. I did not understand how to get sound-out without this stupid STEREO board solution ;)

 

The 400 computer has of course a audio signal on it´s main PCB. The new CPU card just grab this signal from two points (junction R161/C164 Atari 400 mainboard, junction R167/C181 Atari 800 mainboard) and forwards it to the new monitor jack. This is only needed for the 400 or 800, if external monitor jack will be used.

 

Jurgen

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