Differences between XE and XL

[Osbo]

I just got a XE system. So far all the games I tried with SIO2PC works. Are there games only for the XE system? And what are the differences other than the case and detachable keyboard?

[Goochman]

You have an XE Game System correct? That is the only one with a detachable keyboard -

 

There are some port connector differences between the 800XL and the XEGS. The XEGS comes with Missile Command built in (130XE and 65XE do not). The XEGS also comes with a better MMU chip called Freddie.

 

There are some additional changes in the 130XE/65XE line. Very few progs require more than 64K which the 130XE has.

[Osbo]

yeah, the system and the manual says atari xe system. I have an 800xl too. I knew about the build in game (missile command) is there any other game(s) specific for this system?

[+kheller2]

yeah, the system and the manual says atari xe system. I have an 800xl too. I knew about the build in game (missile command) is there any other game(s) specific for this system?

911828[/snapback]

 

They are all cross compatible between XL(w/ 64K) and XE line.

[Gregory DG]

The only cart game I can think of that might have a problem is Flight Sim II. I think it requires 128 K (but doesn't the XEGS only have 64?) so there's probably some banking going on or something.

[miker]

Flight Sim II cart is bank-switching but requires 64k, not 128k of RAM.

And the XEGS models have 64k, just like 800XLs and 65XEs.

[Osbo]

I opened the keyboard the other day to clean it up, and there is a little red led, but I couldn't get it to work.

[Piotr D. Kaczorowski]

800XL (and 65XE) doesn't have pullup resistors for PB2-PB6 (PIA).

Edited September 6 by Piotr D. Kaczorowski

[+MrFish]

3 hours ago, Piotr D. Kaczorowski said:

800XL (and 65XE) doesn't have pullup resistors for PB2-PB6 (PIA).

 

Congrats!

 

 

[Piotr D. Kaczorowski]

@MrFish,

 

Thank you very much, and after thinking it over, I fully agree

[Rybags]

Why the need for pullups?  I seem to recall posted not so long ago little known information that PORTB has internal pullups where PORTA doesn't.

Which explains why PORTB 0->1 transitions don't experience the lag like PORTA does.

[Piotr D. Kaczorowski]

@Rybags,

 

I haven't given it much thought yet. The 130XE has PORTB lines connected to the EMMU, while the 800XL/65XE does not. The used lines are connected via 3k (or 3.3k) pull-up resistors.

There are many smart people here. Some surely know. Maybe they'll tell us too.

 

For now, I'm gathering information about the differences between XL and XE, as I'm interested in the COLD BOOT (Rapidus) issue reported by FJC.

 

I also have concerns about a few other things, but I won't be sharing them until I have solutions. These topics mainly involve the impact of various extensions on cross-talk in the data and address buses, the use of serial termination with resistors to prevent it, as well as the power traces and their routing around the motherboard and various Atari chips.

[Marius]

To get back on topic haha: I believe basketball doesn't work correctly on XEGS with the keyboard attached (or detached, can't remember) ... I believe because the attached/detached flag was formerly used in the 400/800 for something else (has something todo with the extra joystick ports compared to the XL and XE(GS).) In Basketball it causes issues.

[Rybags]

The TRIG2 and 3 lines do other duties on XL/XE.

TRIG3 on all becomes the cartridge sense.

TRIG2 is keyboard sense for XEGS.

 

The OS replicates the port 1/2 values into the shadows representing ports 3/4.  But some games read the hardware registers directly, and games that support 4 at once can run into problems.

[TGB1718]

On 9/6/2024 at 5:04 PM, Piotr D. Kaczorowski said:

I haven't given it much thought yet. The 130XE has PORTB lines connected to the EMMU, while the 800XL/65XE does not. The used lines are connected via 3k (or 3.3k) pull-up resistors.

There are many smart people here. Some surely know. Maybe they'll tell us too.

The resistors are there probably as PORTB can be Tri-state and maybe there were issues if they went inactive (floating).

Also the pullup devices in PORTB are active and can not go above 2.4V when high, so adding a pullup makes sure

its 5V when logic '1'

[Piotr D. Kaczorowski]

1 hour ago, TGB1718 said:

The resistors are there probably as PORTB can be Tri-state and maybe there were issues if they went inactive (floating).

Also the pullup devices in PORTB are active and can not go above 2.4V when high, so adding a pullup makes sure

its 5V when logic '1'

I've checked the 800XL motherboard and PIA's PORTB lines. Both sides are not connected, so I assume that an unsteady state, rather than a tri-state, might occur on those lines.