New GTIA chips!

[atariksi]

Sure would be a good time to add some minor improvements to the GTIA. For example, make the color-lum registers 8 bits instead of 7, i.e. use all 4 luma bits to get 256 colors. Add 7 more color-lum registers to change the 9-color GTIA mode into a 16-color mode.

Curt, are such enhancements out of the question? We could call it the VTIA!

 

Or are you looking to faithfully reproduce the original?

 

May need to modify some things anyway if the repductions can't get the color clock shifts right on the Gr.9 vs. Gr.10. Here's an idea:

 

Get rid of the self-test and replace it with a BIOS configuration (i.e., make it more useful):

Allow user to select from BIOS A7800 MARIA or A800 GTIA/ANTIC chipset and gives readout of current cartridge type plugged in whether it's A7800 or A800.

Allow user to select boot drive letter or boot from joystick port.

Allow user to set date/time.

Allow user to select PAL/NTSC

...

and it keeps the settings on cold boot without requiring a battery.

 

I guess the enhancements to GTIA can be selected via software as program needs them.

[Curt Vendel]

I think what may be best is to establish a new section of Atari Museum devoted to the chips or I'm going to register a new domain and its purpose will be to put the data out there, put together a highly technical forum and then tie that forum over to Atariage for people to discuss the work - similar to the way the Programming area is apart from the console forums.

 

The reason for this is I'd like to generate a discussions on the designs, implementations, tests, results and improvements and keep the a lot of the "wishlist" crowd out of the discussions from day to day. I'm not saying anyone would be barred, it will again - be just like the programming section, but focused strictly on that, and to keep more common talk/discussion to the other forums.

 

So this will be the 2010 project - the "Year we make Contact" (with the inner Atari's)

 

 

 

Curt

[dwhyte]

So this will be the 2010 project - the "Year we make Contact" (with the inner Atari's)

 

Righteous! I eagerly await the results of your hard work.

[Kalvan]

Do you have plans to do the SYLVIA chipset?

[Bongomat]

Hi Curt,

 

this is good news and marvellous work you do there. A friend and I tried to implement the XL in a FPGA. But it is pretty much reverse engineering with a lot of traps and problems - since we both don't have access to a logic analyzer. This will be sped up considerably with your achievements. Maybe a VHDL definition could be genereated nearly automatically with the data you get...

 

I'm looking forward to hearing from your progress.

 

Elmar

[philipj]

How in the world did I miss this topic... This makes me glad I purchased a 1200 XL from a local flea market. This is excelent news.

 

I think the Atari Lynx used a good chip set especially the "Suzy chip" with the coprosessor. Imagine an 800 with the power of an Atari lynx.

[Curt Vendel]

Lynx is another situation - I have all of the data from the original tapes of the Lynx, I found the entire bankers box with not only all of the original Epyx documents, but also copies of RJ Micals and Dave Needles engineering journals so the Lynx is something that I want to get something going on later in 2010, right now the focus is on the 8bit computers and possibly something with the 2600/7800 chips.

 

I'm talking with a good friend and former VLSI engineer about extracting the SPICE netlist data out of the GDS files to see if it can be transposed over to VHDL, its not a straight forward process and may have some stops and starts, but it looks like it will be doable with some elbow grease and some determination, lets hope for the best that we can make this a reality and not a pipedream.

 

Someone commented that the GTIA had mostly been redone in the new XE video board, which is great - but is that data freely out there for all to access? If not, then doing this work and putting this material out for all to access and work on is a must if we are going to breathe a new level of life into the 8bits in physical products and designs.

 

 

Curt

 

How in the world did I miss this topic... This makes me glad I purchased a 1200 XL from a local flea market. This is excelent news.

 

I think the Atari Lynx used a good chip set especially the "Suzy chip" with the coprosessor. Imagine an 800 with the power of an Atari lynx.

[yuppicide]

Great news. I don't really know Curt or much about him, but he's one of the people on here I like to think of as Macgyver. They seem to know and do a lot.

[Retro Rogue]

I don't really know Curt or much about him, but he's one of the people on here I like to think of as Macgyver.

 

 

ROFL. Maybe David Lightman meets Punky Brewster, but MacGyver?

[GroovyBee]

MacGyver! Only if he'd designed things using a swiss army knife, duct tape, some wire, 3 pieces of chewing gum and a small foreign coin.

Edited December 26, 2009 by GroovyBee

[ijor]

GDS and/or netlist files would be awesome to have. Were the GDS files posted in this thread at all? I can't find them.

 

However, both GDS and netlist files are almost useless for a modern recreation. Except, of course, for helping in the reverse engineering. But for the purpose of reverse engineering, schematics are far much more useful.

[ninoy1995]

Im not much of a tech guy, does this mean that an Atari 2600 remake from Legacy Engineering a possibility? Thanks Guys!

[carmel_andrews]

Claus...Tweaking the GTIA to do more things is interesting, as would the idea of 3 gtia i.c's like someone suggested... a better idea would be a design like the one they used for pucka US doubler's, I.E have all the chips in the same package

[supercat]

Thus, if you could just translate the TIA back into VHDL this would be of great help to those of us who like to experiment with FPGAs and old video game architectures such as the Atari2600.

 

Translation from NMOS to VHDL is apt to be tricky. There are a variety of tricks one can use in NMOS which aren't practical in CMOS; I don't think such tricks would translate into VHDL either.

 

BTW, I wonder if anyone ever constructed a two-transistor-plus-one-resistor XOR gate in NMOS. The input load will be variable, but even adding inverters on the inputs one would still come out ahead of a normal three-gates implementation.

Edited December 30, 2009 by supercat

[+CharlieChaplin]

Well,

 

the topic is "new GTIA chips" - what about new Antic chips ?!? Or some upgraded Antic chips...?!?

 

-Andreas Koch.

[Bryan]

Translation from NMOS to VHDL is apt to be tricky. There are a variety of tricks one can use in NMOS which aren't practical in CMOS; I don't think such tricks would translate into VHDL either.

 

I remember the first time I saw the "input capacitance as a short-term register" trick. I can't imagine how much die space that saves.

[Curt Vendel]

Well, I'm going to focus more on the CGIA and KERI as they are in CMOS, also I'm going to release the files for the SARA-B shortly as a starting point, I'll have a new set of pages up in February devoted to the Atari Semiconductor Group, I'll post when this is ready. Got a few other things on my plate right now like putting the finishing touches on the new PC keyboard encoder for XL/XE computers as part of the Pizza-Box 1200XL project, so I need to get that wrapped up, that is also going to help get things back on track for another project I've had waaaaaaaaaaaaaay on the backburner for a while.

 

 

Curt

 

Translation from NMOS to VHDL is apt to be tricky. There are a variety of tricks one can use in NMOS which aren't practical in CMOS; I don't think such tricks would translate into VHDL either.

 

I remember the first time I saw the "input capacitance as a short-term register" trick. I can't imagine how much die space that saves.

[+Stephen]

Well, I'm going to focus more on the CGIA and KERI as they are in CMOS, also I'm going to release the files for the SARA-B shortly as a starting point, I'll have a new set of pages up in February devoted to the Atari Semiconductor Group, I'll post when this is ready. Got a few other things on my plate right now like putting the finishing touches on the new PC keyboard encoder for XL/XE computers as part of the Pizza-Box 1200XL project, so I need to get that wrapped up, that is also going to help get things back on track for another project I've had waaaaaaaaaaaaaay on the backburner for a while.

 

Curt

Very cool that you have a CMOS starting point. I still think it's insanely cool you recovered the original files as well. Even if they don't get rebuilt in that form, the information is still out there.

 

Stephen Anderson

[HARMIK]

Awesome awesome stuff Curt thank you.

[+grafixbmp]

I so hope you waaaaay backburner project has something to do with portable 2600's. (I miss you so FB portable 2) *CRIES*

[+Allan]

I so hope you waaaaay backburner project has something to do with portable 2600's. (I miss you so FB portable 2) *CRIES*

I was hoping it was the 7800 keyboard with OSS's BASIC and Videowriter.

 

Allan

[supercat]

Well, I'm going to focus more on the CGIA and KERI as they are in CMOS, also I'm going to release the files for the SARA-B shortly as a starting point, I'll have a new set of pages up in February devoted to the Atari Semiconductor Group, I'll post when this is ready.

 

Out of curiosity, how hard would it be to produce a graphical rendering of STELLA with transistor-level resolution? I'd be curious to see how the physical layout of the chip compares with the schematics.

[Curt Vendel]

Give that man a cookie...

 

 

I so hope you waaaaay backburner project has something to do with portable 2600's. (I miss you so FB portable 2) *CRIES*

I was hoping it was the 7800 keyboard with OSS's BASIC and Videowriter.

 

Allan

[Level42]

New here, but a long time Atari fan (From 2600 to ST and everything in between). Although I still have several of those machines, I'm mostly into arcade collecting now though. I wonder if a DIL Pokey would be possible and commercially interesting ? Pokey's are still widely available today. They are used heavily on arcade games (F.I. my Star Wars cockpit has 4 of them). Although I personally never seen one go bad, it does seem to happen.

 

At least, it's great to know that it would be possible to reproduce them....if we ever run out of them....

[kamakazi]

This is by far the best news I've heard since Atari closed its doors. Looks like it would also benefit the Atari machines that no longer work where replacements parts are hard to find. It wouldn't be too hard to create a single system (like the 2600) using these chips and adapting them to fit into the old-fashioned Atari 2600 shell. I feel a tear coming on. After reading this, these great 8-bit consoles will live on. We should of sent an Atari on that satelite instead of a gold record. Then again, it might of given aliens the wrong impression about us lol. Very interesting Curt, can't wait to see what all developes after this.