6591: The Atari 2600 System-on-a-Chip

[+SvOlli]

Hello!

 

I'd like to hack up my own 2600. To keep the amount of soldering to a minimum I don't want to do the same approach as Ben Heckendorn, soldering all three chips together. Instead I want to go for the 2600-SoC 6591 and alike.

 

I could figure out quite a lot by watching a the different projects and entries in the forum. But there are still some things to figure out.

First of all, there are some pins that I couldn't find a description for. These are 15, 21, 24 and 33. I'm hoping that one of these four might set the bit 3 of port B (Color/BW), which is missing in the current descriptions. Since a couple of games make use of it, and it also is used by the as a configuration switch in some of my demos.

 

The other thing is: is there any chance to get "a couple" of these chips without scraping them from bootleg 2600s which are ~60 Euros on eBay? I tried my luck at the places, where I could find other MOS chips in the past, like the CIA 6526 or the RIOT 6532, etc. but no luck.

 

The first milestone is to have a breadboard system that will be made of the chip, connectors for the console switches like reset, select and difficulty as well as the joysticks. The luma/chroma signal should be merged to a composite, since finding an svideo-capable screen is more difficult than a composite one.

 

Also did anyone decapped the chip? Has MOS created a new silicone, or are those just three dies in one chip?

 

Greetings,

SvOlli

 

[+SvOlli]

Small additions.

Here's this pinout, as I could figure it out so far as ASCII art:

                                ___ ___
                     A4 C : 1 -|   V   |- 48: C A3
                     A5 C : 2 -|       |- 47: C A2
                     A6 C : 3 -|       |- 46: C A1
                     A7 C : 4 -|       |- 45: C A0
                     A8 C : 5 -|       |- 44: A VCC
                     A9 C : 6 -|       |- 43: A GND
    DIFFICULTY P0   PB7 R : 7 -|       |- 42: C A12
    DIFFICULTY P1   PB6 R : 8 -|       |- 41: C A11
    GAME SELECT     PB1 R : 9 -|       |- 40: C A10
    GAME RESET      PB0 R :10 -|       |- 39: C D0
    P0 LEFT         PA7 R :11 -|   6   |- 38: C D1
    P0 RIGHT        PA6 R :12 -|   5   |- 37: C D2
    P0 DOWN         PA5 R :13 -|   9   |- 36: C D3
    P0 UP           PA4 R :14 -|   1   |- 35: C D4
                          :15 -|       |- 34: C D5
    P1 LEFT         PA3 R :16 -|       |- 33:  
    P1 RIGHT        PA2 R :17 -|       |- 32: C D6
    P1 DOWN         PA1 R :18 -|       |- 31: C D7
    P1 UP           PA0 R :19 -|       |- 30: A GND
                  AUDIO T :20 -|       |- 29: T VIDEO CHROMA
                          :21 -|       |- 28: A VCC
    P0 FIRE       INPT4 T :22 -|       |- 27: T VIDEO LUMA
    P1 FIRE       INPT5 T :23 -|       |- 26: C /RESET
                          :24 -|_______|- 25: T CLK

The external functions are added, and the IDs should explain themselves. The single letter is the component which typically drives this pin. [C]PU, [R]IOT, [T]IA, [A]LL (for power).

 

Another thing that I forget in the last post was that I've encountered three different numbers for 2600 SoCs so far.

6591, 6592 and 8591. My guess is that 6591 and 6592 generate different TV signals. And my guess is that the 6591 is done in NMOS technology while the 8591 is done in HMOS(2). This would resemble the rest if the MOS numbering scheme: 6581 is the SID in NMOS, while the 8580 is the one in HMOS(2). Some for the CPU 65xx vs 85xx, but the lower numbers don't have to match, as the 8500 has the same pinout as the 6510.

 

[pcrock]

On 30/07/2019 at 16:52, SvOlli said:

Small additions.

Here's this pinout, as I could figure it out so far as ASCII art:

                                ___ ___
                     A4 C : 1 -|   V   |- 48: C A3
                     A5 C : 2 -|       |- 47: C A2
                     A6 C : 3 -|       |- 46: C A1
                     A7 C : 4 -|       |- 45: C A0
                     A8 C : 5 -|       |- 44: A VCC
                     A9 C : 6 -|       |- 43: A GND
    DIFFICULTY P0   PB7 R : 7 -|       |- 42: C A12
    DIFFICULTY P1   PB6 R : 8 -|       |- 41: C A11
    GAME SELECT     PB1 R : 9 -|       |- 40: C A10
    GAME RESET      PB0 R :10 -|       |- 39: C D0
    P0 LEFT         PA7 R :11 -|   6   |- 38: C D1
    P0 RIGHT        PA6 R :12 -|   5   |- 37: C D2
    P0 DOWN         PA5 R :13 -|   9   |- 36: C D3
    P0 UP           PA4 R :14 -|   1   |- 35: C D4
                          :15 -|       |- 34: C D5
    P1 LEFT         PA3 R :16 -|       |- 33:  
    P1 RIGHT        PA2 R :17 -|       |- 32: C D6
    P1 DOWN         PA1 R :18 -|       |- 31: C D7
    P1 UP           PA0 R :19 -|       |- 30: A GND
                  AUDIO T :20 -|       |- 29: T VIDEO CHROMA
                          :21 -|       |- 28: A VCC
    P0 FIRE       INPT4 T :22 -|       |- 27: T VIDEO LUMA
    P1 FIRE       INPT5 T :23 -|       |- 26: C /RESET
                          :24 -|_______|- 25: T CLK

The external functions are added, and the IDs should explain themselves. The single letter is the component which typically drives this pin. [C]PU, [R]IOT, [T]IA, [A]LL (for power).

 

Another thing that I forget in the last post was that I've encountered three different numbers for 2600 SoCs so far.

6591, 6592 and 8591. My guess is that 6591 and 6592 generate different TV signals. And my guess is that the 6591 is done in NMOS technology while the 8591 is done in HMOS(2). This would resemble the rest if the MOS numbering scheme: 6581 is the SID in NMOS, while the 8580 is the one in HMOS(2). Some for the CPU 65xx vs 85xx, but the lower numbers don't have to match, as the 8500 has the same pinout as the 6510.

 

 

[pcrock]

Hi. I know that this is an old post but I have some information.

I own a Brazilian PAL-M console that uses the 6592 chip. The oscillator xtal frequency is 14.30244Mhz. It works great.

Today I received a piece IC marked 6591(92). I decided to try it in the circuit putting it in the place of original 6592 ic and all works great too. With colors working in PAL-M all ok.

I also tried on both IC (6591(92) and 6592) to use a NTSC xtal version (14.31818Mhz) but I got no colors!!! The games runs ok but only black and white screen is get.

 

PS--> 6591 and 6592 chip is an Atari 2600 all in one chip. It appears that it haves a very impressive compatibility with a real console that uses the 3 famous chips (6507 6532 6526) and It can run all games I tested but IT IS NOT COMPATIBLE with paddles (but is ok  compatible with the Drive controller).

6591/6592 chips haves four pins that is not connected to circuit. I made a lot of tests with then but now I am sure. This chips IS DEFINITELY NOT COMPATIBLE with paddles.

Edited March 15 by pcrock

[+SvOlli]

Of course they are not. They lack the pins that are required for paddles. The paddles are connect to an analogue pin each.

[pcrock]

3 hours ago, SvOlli said:

Of course they are not. They lack the pins that are required for paddles. The paddles are connect to an analogue pin each.

That Is exactly what I said.

But since exists 4 not connected pins in that IC, I did some tests with it to be sure that those pins could (or not) to be the paddle pins. 

In Brazil there exist some Atari 2600 clones (by Milmar) that not supports paddles but only the connexion is needed. The circuit is already there! You just need to add 4 wires.

 

[+x=usr(1536)]

After re-reading @pcrock's post, I realised that I had misunderstood what he was saying.  Deleted.