XL/XE compatible Atari 800?

[Tempest]

Not to rush you or anything, but is there an ETA on this project or is it a "It's done when it's done" kind of thing? I've been waiting for something like this for a long time and now that I'm using my 800 instead of my 800XL I really want it.

 

Tempest

[iainjh]

my soldering skills are ...limited. I can follow instructions, but I cant etch a PCB (if thats still the right term, its an old term I recall from my dad) or work stuff out myself. doh!

 

I guess I got spoilt recently with my Sdrive, would love it to be able to buy something as cool as this and get my 800 into proper full time use. Even if a board is not the full solution.

 

Thanks for replying warerat and I understand we all have 'lives' to live. would still find it v cool if it did progress.

 

 

cheers, Iain

[timofonic]

Any news about this? I'm HIGHLY interested on this upgrade! I only need the schematics if manufacturing isn't possible...

 

 

Adding VBXE compatibility and other addons could be awesome too

Edited November 3, 2009 by timofonic

[+warerat]

Any news about this? I'm HIGHLY interested on this upgrade! I only need the schematics if manufacturing isn't possible...

 

 

Adding VBXE compatibility and other addons could be awesome too

 

Well, the schematics for this are surprisingly simple (four IC's-- two SRAMs, one ROM, one 100-pin CPLD, handful of pullups, a 3.3V regulator, and a Maxim reset IC). But completely useless without the CPLD core logic which controls the whole thing and is where all my time, sweat, and tears have gone. So yes, this has consumed 100s of hours of my time to perfect it to where it is today while still having a life that doesn't involve Atari or computers.

 

As a result of changing my design philosophy on this several times since I first started I decided to make some hard decisions about how this gets installed. As a result, this is an obtrusive (but not destructive) install and once it's in there, you can't go back to bone-stock (original OS and memory cards will not work) unless you remove the entire upgrade. You have to pull two IC's from the motherboard (and have jumpers in place on a few pins) as I re-purpose some of the pins on the OS slot to reduce the external wiring necessary. As an 800 owner I know it's impractical to have to pull out cards if you want to go back to stock so I've successfully implemented BOTH architectures at the hardware level and they are jumper selectable-- I think you'll agree that makes up for it. So if you want to go back to 4-port 800 mode you just move the jumpers. There are a few things I need to verify as a feel-good measure to validate specific portions of the hardware implementation but for all intents and purposes this is an All-In-One Personality module that pretty much can make the 800 act like any 800/XE model. Remember ports 3/4 don't work for joysticks in XE mode, but you can still use 8 paddles and no trigger on port 4..

 

So what it looks like now:

Stock 48K 800 OS-B (verified OK)

Stock 52K 800 OS-B (verified OK, RAM at $C000-$CFFF)

Axlon 512K 800 OS-B (verified OK, with Claus Buchholz Tron animation, Axlon diags)

 

Stock 128K 130XE ANTIC-enhanced (verified OK)

Peterson 320K 130XE 8ACE (verified OK)

Peterson 576K 130XE 8ACE (verified OK)

CompyShop 576K 130XE 26AE ANTIC-enhanced (looks OK, but has trouble with some demos-- I'd have to validate with someone who has this). But then again I could just add another SRAM for full 1088K, but not much software to use it.

 

XE mode is 100% PORTB compatible, including built-in BASIC C. And yes, it should be VBXE compatible but I'll know for sure when I get my VBXE board here this month. There would be major logistical problems squeezing it on the CPU board and getting it back in the metal housing. It could be plugged into a custom board that connects to one of the free memory slots with handful of connections to ANTIC as I provide all the XE ECI signals and hardware I/O from the OS board. PBI is implemented, but again, logistically difficult getting that ribbon cable out of the metal cage, but not impossible.

 

Thanks for being patient.

[MEtalGuy66]

Sounds kick-ass...

 

So there will be a header that includes all of the ECI/PBI signals for those who want to connect some sort of cable to connect a PBI device?

[+warerat]

First off, I'd like to thank Larry White in the community for trusting a complete stranger off the 'net and letting me borrow his Bit 3 FullView-80 to test in this modified 800 rig.

 

So I've validated that in 800 mode you can still run your slot 3 80-column boards (and keep 48K/52K/512K Axlon modes). This has interesting implications in 130XE mode as it would not normally be possible on a real XL or XE computer. The 6545 CRTC hardware registers are still visible at $D5XX so you could make a driver in 130XE mode to control the 80-column display. The downside is there are lots of devices using that same address space. The Bit 3 maps its 4K ROM a page at a time at $D6XX but from what I disassembled of it, there are many references to OS-B ROM locations. What makes the board unique to the 800 is a signal on the bus called EXSEL- (not to be confused with XL/XE EXTSEL-) that disables the databus buffers that connect the personality slot module to the CPU.

 

I'm still learning how this board interacts with the memory map but under real conditions you have to ignore EXSEL- in XE mode as it's technically not valid for that architecture. If I do that I don't see the ROM get mapped in for XE mode. As an experiment, allowing EXSEL- to work in XE mode makes the Bit 3 ROM completely visible. Except for all those OS-B references that hang the machine... Good stuff.

 

Thanks, Larry!

[+bf2k+]

That's a nice clear 80 col display... I like.

[+warerat]

For the metallurgically challenged (re: you suck at soldering and running jumpers but can take the computer apart), there's a paddle board that re-wires a few pins on the OS slot and only needs six connections to the CPU board. Just pull the two TTL chips, plug this board in it's place, and it's all underneath the plastics. Only needs six wires to the CPU board. If you can handle a 32-in-1 OS installation, you can handle this. Can't plug your old boards back in with this installed but at this point in the design you can turn it back to a stock 800 with the flip of a jumper.

[FastRobPlus]

For the metallurgically challenged (re: you suck at soldering and running jumpers but can take the computer apart), there's a paddle board that re-wires a few pins on the OS slot and only needs six connections to the CPU board. Just pull the two TTL chips, plug this board in it's place, and it's all underneath the plastics. Only needs six wires to the CPU board. If you can handle a 32-in-1 OS installation, you can handle this. Can't plug your old boards back in with this installed but at this point in the design you can turn it back to a stock 800 with the flip of a jumper.

 

This is really cool. It could lead to a jump in Atari 800 use!

It might be too late for me. I bit the bullet and bought a couple of 1200XLs and packed my 800 up for sale.

[+remowilliams]

For the metallurgically challenged [...]

Wow that looks great! Can't wait!

[Tempest]

Any update? I finally got my S-video modded 800 and I'm dying to get this module

 

Tempest

[Almost Rice]

I would like to know too. My 800 module seems to have stopped working.

[Tempest]

Bump?

[iainjh]

polite bump?

 

for any update or eta or if the project lives (it lives! ) etc

 

TIA

[Defender II]

First off, I'd like to thank Larry White in the community for trusting a complete stranger off the 'net and letting me borrow his Bit 3 FullView-80 to test in this modified 800 rig.

 

So I've validated that in 800 mode you can still run your slot 3 80-column boards (and keep 48K/52K/512K Axlon modes). This has interesting implications in 130XE mode as it would not normally be possible on a real XL or XE computer. The 6545 CRTC hardware registers are still visible at $D5XX so you could make a driver in 130XE mode to control the 80-column display. The downside is there are lots of devices using that same address space. The Bit 3 maps its 4K ROM a page at a time at $D6XX but from what I disassembled of it, there are many references to OS-B ROM locations. What makes the board unique to the 800 is a signal on the bus called EXSEL- (not to be confused with XL/XE EXTSEL-) that disables the databus buffers that connect the personality slot module to the CPU.

 

I'm still learning how this board interacts with the memory map but under real conditions you have to ignore EXSEL- in XE mode as it's technically not valid for that architecture. If I do that I don't see the ROM get mapped in for XE mode. As an experiment, allowing EXSEL- to work in XE mode makes the Bit 3 ROM completely visible. Except for all those OS-B references that hang the machine... Good stuff.

 

Thanks, Larry!

 

Put me on the list for 2.

It was the ability to use it with my Bit-3 80-col card that is what convinced me!

[Tempest]

Another bump. I'm really interested in this.

 

Tempest

[iainjh]

I sort of asked this before, but would like to ask again more specifically - is there an alternative I could look for to update my 800 to be compatible with XL and more ram for demos etc? any suggestions please are welcome.

 

I do have an xl, but the A800 has a special magic and I'd love to use it more.

 

cheers all and esp to warerat who did such cool stuff in the earlier posts. still v cool.

[OldAtarian]

Another bump. I'm really interested in this.

 

Tempest

 

I'd be interested in a clone of the Bit-3 80 column board.

[+Stephen]

Another bump. I'm really interested in this.

 

Tempest

 

I'd be interested in a clone of the Bit-3 80 column board.

Same here!

[+warerat]

I'm back after a long hiatus.

 

This thing hasn't been forgotten. From a design and prototype perspective it is complete and does exactly as advertised (and more). I'm not going to lie-- I've been a slug and have had other things going on so I haven't finished the PCB layout for this. But it is a single card solution and does require soldering some jumper wires.

[iainjh]

cool!

 

do you think it will be available to buy /make at all?

 

v happy to make it worth your while or assemble from pcb if easier /better..

 

 

whatevers good! please let us know ..

 

[Tempest]

But it is a single card solution and does require soldering some jumper wires.

Did you ever make a switch that can turn off the XL compatibility mode or is that impossible?

 

Glad to hear you're still working on this.

 

Tempest

[+warerat]

But it is a single card solution and does require soldering some jumper wires.

Did you ever make a switch that can turn off the XL compatibility mode or is that impossible?

 

Glad to hear you're still working on this.

 

Tempest

 

Yep, you can select between stock 800 and XL. So one board can look like seven different Ataris.

[iainjh]

what do you think warerat ? :)anything we can do to help (beyond bugging you )

 

cheers as ever Iain

 

 

 

 

cool!

 

do you think it will be available to buy /make at all?

 

v happy to make it worth your while or assemble from pcb if easier /better..

 

 

whatevers good! please let us know ..

 

[joeventura]

 

It's Over Johnny!