556 replies to this topic

[Tempest]

I've asked this before, but I figured I'd ask again just incase some has thought of something new in the past year or two. Is it possible to hack an Atari 800 so it is compatible with Atari XL/XE software that requires 64K+?

Tempest

[remowilliams]

Hopefully sometime soon

[zektor800]

Yeah, I am waiting for this as well. At least a 64k XL/XE can be modified to add 800 compatibility....but I would still *love* to have my 800 used as my "main" machine.

[warerat]

Tempest, on Thu Nov 16, 2006 11:29 AM, said:

I've asked this before, but I figured I'd ask again just incase some has thought of something new in the past year or two. Is it possible to hack an Atari 800 so it is compatible with Atari XL/XE software that requires 64K+?

Tempest

Absolutely! Same applies to the 400.

http://www.atariage....showtopic=84836
http://www.atariage....p;#entry1167756

Edited by warerat, Thu Nov 16, 2006 9:10 PM.

[carmel_andrews]

someone's already doing that aren't they...isn't that you WERERAT

[Almost Rice]

Its warerat. I think tempest had asked this before in 2003 or 2002 and got no response.

Edited by Almost Rice, Fri Nov 17, 2006 9:39 AM.

[Tempest]

Oh sweet!

Tempest

[carmel_andrews]

I think there might be an issue with the Port B location ($D301)

In the 800 it's used for joysticks 3/4, in the xl/xe it's used for bank switching...has wererat come across this yet

Also any dos older then dos 2.5 (ramdisk version), with built in 800 stylee ramdisk option, if loaded in xe mode might still be trying to access mem. loc $d800 (the 800/400's bank switching location) in an xl/xe this location might not be used and therefore might crash the program (dos)

[warerat]

carmel_andrews, on Sat Nov 18, 2006 3:20 AM, said:

I think there might be an issue with the Port B location ($D301)

In the 800 it's used for joysticks 3/4, in the xl/xe it's used for bank switching...has wererat come across this yet

Also any dos older then dos 2.5 (ramdisk version), with built in 800 stylee ramdisk option, if loaded in xe mode might still be trying to access mem. loc $d800 (the 800/400's bank switching location) in an xl/xe this location might not be used and therefore might crash the program (dos)

This upgrade converts the memory map on the 800. I thought I explained this thoroughly before in the older threads relating to the upgrade, but with this board plugged in, you *lose* 800 compatibility. Ports 3/4 are electrically connected to the board (hence the need for running connections to the motherboard), so therefore the memory map is identical to one on that of a XL/XE. As a result, you *cannot* use ports 3 and 4. If you plug joysticks in there and try to use them, you will crash the machine. The 800 can be returned to stock by plugging in the original boards.

I have studied the 400/800 architecture very thoroughly and I understand where and what changes need to be done to meld the bridge between these first-generation Atari's and the later models. So any plug-in cards that work in the 800, will no longer work. No Omnimon, no Omniview, and no memory cards of any kind. XL/XE hardware compatibility and full 800 compatibility are mutually exclusive, period. This is a single board that plugs in the personality module slot. Therefore in keeping with Atari's original intention for this machine, you can change the "personality" of the machine by switching boards. Well, you can.

So to address your statements directly:

Quote

In the 800 it's used for joysticks 3/4, in the xl/xe it's used for bank switching...has wererat come across this yet

Yes, and Yes. In this 800 upgrade, PIA PORTB is used for XL/XE memory management. You lose the ability to run devices in ports 3/4. None of this would be possible in a compatible way if you didn't give up ports 3/4.

Quote

Also any dos older then dos 2.5 (ramdisk version), with built in 800 stylee ramdisk option, if loaded in xe mode might still be trying to access mem. loc $d800 (the 800/400's bank switching location) in an xl/xe this location might not be used and therefore might crash the program (dos)

Why do you say the bank switching area is $D800? What specific brand of 800 memory upgrade did this? Axlon banked memory via writes to $CFFF to select the bank, and the bank appeared in 16K increments in $4000-$7FFF. Some home-built 800 upgrades used $D700 instead, but the memory still appeared in $4000-$7FFF. Some other boards mapped the remaining 16K out of the 64K in $C000-$CFFF, in 4K increments. Regardless, it doesn't matter. $D800 is the 2K Floating Point ROM in both the 800 and the XL/XE. There is no way to switch it out, unless you have a PBI device, which while the hooks are there in this upgrade to do it, it is not specifically implemented.

You have a full XL/XE memory map, so it makes about as much sense to run an 800 version of a ramdisk program that doesn't work on an XL/XE on this modified 800, which from a hardware perpective, *IS* a XL/XE. So yes, naturally, it will not work. No 800 style bankswitching will work with this.

There are a few folks here in the forum that have either seen this personally, or have some of my initially modified cards and can validate software compatibility:

Metalguy66 (has seen my 800)
Almost Rice (has a true 64K 800 with 800XL compatibility, no switchable BASIC or selftest, also has seen it)
JR> (64K 800, 800XL compatibile, no switchable BASIC or selftest)
doctorclu (has the second of the 576K upgrade, full 130XE, his plugs into ports 3/4)

I'm not modifying ROM cards for this anymore, it's easier just to build a PCB with everything on one board.

The only thing this upgrade doesn't provide, is a HELP key.

[warerat]

Just an update for those that are interested how this is coming along.

I finally finished verifying the behavioral simulations before committing the design into silicon. Looks like every thing works like it should in the Altera simulator. In the aerospace business we get a long company holiday (today is my last day of work until next year) so I will spend some time finishing the wiring on the prototype board and seeing if it works in real hardware.

If it works from there, then it's just a matter of sourcing parts and generating a finished PCB. The current design supports three unique configurations (stock 128K 130XE, 320K 130XE w/BASIC, 576K 130XE wo/BASIC) selectable via two jumpers. If you want to save some money and don't care to have the 320K/576K modes, then the board can be populated with a single 128K SRAM and the 512K chip can be added later if desired.

I'll keep you posted on further progress.

[Gunstar]

warerat, on Thu Dec 21, 2006 10:31 PM, said:

Just an update for those that are interested how this is coming along.

I finally finished verifying the behavioral simulations before committing the design into silicon. Looks like every thing works like it should in the Altera simulator. In the aerospace business we get a long company holiday (today is my last day of work until next year) so I will spend some time finishing the wiring on the prototype board and seeing if it works in real hardware.

If it works from there, then it's just a matter of sourcing parts and generating a finished PCB. The current design supports three unique configurations (stock 128K 130XE, 320K 130XE w/BASIC, 576K 130XE wo/BASIC) selectable via two jumpers. If you want to save some money and don't care to have the 320K/576K modes, then the board can be populated with a single 128K SRAM and the 512K chip can be added later if desired.

I'll keep you posted on further progress.

Glad to know you will have the time over the holidays to work on this some more! I'll be buying your 576k model when the time comes and buying another 800 (sold my other one last summer) just for this upgrade! Not sure what I'll do with my 320k XE and Rambo 1200XL after that, but the XE will probably be the one to go. I recently started a new job in the industrial/heavy equipment manufacturing sector and we too have a long company holiday! Friday the 22nd is my last day, and I return on Jan. 2nd! I'll also be finishing/starting a lot of long overdue electronic projects over the holidays! Though mine are personal and not something I'm making to sell (though I'm glad you are; I could do this mod for myself, especially if I had your schematics, but I'd rather buy yours as I've got too much on my plate already!).

P.S., I think it's really cool that you are using an Altera to do the circuitry and run simulations; I learned to use it while I was studying electronics back in 2001/02 and have intended to buy my own ever since, but I haven't had an extra few hundred to do it yet! It's a magnificent piece of equipment. I loved just dragging the components around in the window and instantly testing the circuits! I had actually thought about putting an entire 8-bit onto the Altera and then burning a custom chip out of it to make a portable at one time. The plan was to use a Lynx case&screen since the Lynx screen resolution is the same as Gr. 7 on the 8-bit, and have a scrolling feature for the higher resolutions. But I'd just use a more modern portable with higher res. screen now.

Edited by Gunstar, Thu Dec 21, 2006 5:00 PM.

[warerat]

Gunstar, on Thu Dec 21, 2006 4:51 PM, said:

P.S., I think it's really cool that you are using an Altera to do the circuitry and run simulations; I learned to use it while I was studying electronics back in 2001/02 and have intended to buy my own ever since, but I haven't had an extra few hundred to do it yet! It's a magnificent piece of equipment. I loved just dragging the components around in the window and instantly testing the circuits! I had actually thought about putting an entire 8-bit onto the Altera and then burning a custom chip out of it to make a portable at one time. The plan was to use a Lynx case&screen since the Lynx screen resolution is the same as Gr. 7 on the 8-bit, and have a scrolling feature for the higher resolutions. But I'd just use a more modern portable with higher res. screen now.

This a pure combinatorial design, it would use about 150 equivalent discrete gates, about 20 inputs, and 10 outputs, so a CPLD with lots of I/O is all you need, as well as all the logic equations. It's just a custom address mux/decoder that integrates in the 800 bus slot. The design is coded in VHDL so there's no dragging around of any circuits.

The tools to design CPLDs and FPGAs don't cost anything, you can download Xilinx Web Editions and Altera Quartus II for free that cover any devices you could conceivably use to design something for the Atari.

Edited by warerat, Thu Dec 21, 2006 6:40 PM.

[doctorclu]

warerat, on Sat Nov 18, 2006 10:34 AM, said:

doctorclu (has the second of the 576K upgrade, full 130XE, his plugs into ports 3/4)

I'm not modifying ROM cards for this anymore, it's easier just to build a PCB with everything on one board.

The only thing this upgrade doesn't provide, is a HELP key.

All I have to say is I love this modification and use it practically daily in my BBS'ing. Nothing like an Atari 800 running Ice-T XE (which is not normally possible) and running the MyIde Flash cart (also not usable on a stock 800).

When Warerat makes the next run of the 576K XE mods, I'll probably pick one up. Either that or a 128K mod. Figure use that one and preserve the Beta version.

[warerat]

doctorclu, on Thu Dec 21, 2006 10:25 PM, said:

warerat, on Sat Nov 18, 2006 10:34 AM, said:

doctorclu (has the second of the 576K upgrade, full 130XE, his plugs into ports 3/4)

I'm not modifying ROM cards for this anymore, it's easier just to build a PCB with everything on one board.

The only thing this upgrade doesn't provide, is a HELP key.

All I have to say is I love this modification and use it practically daily in my BBS'ing. Nothing like an Atari 800 running Ice-T XE (which is not normally possible) and running the MyIde Flash cart (also not usable on a stock 800).

When Warerat makes the next run of the 576K XE mods, I'll probably pick one up. Either that or a 128K mod. Figure use that one and preserve the Beta version.

Yeah, that version of the mod is *very* alpha. Only two of those complete complete mods in existence that I know of, unless someone else has done it (yours and mine). If I can't find a reliable source of reasonably priced 512K DIP SRAMs, I'll have to move to SMT based ones. Fortunately, I don't forsee that being an issue for at least a couple of years-- there are still plenty of DIPs out there, even on new designs but eventually that will dry up.

[warerat]

Status update. Some progress-- I got some signs of life, but display is garbled. You can see the 800 6502 jumping to the reset vector and running the code from the XL OS.

Stay tuned.

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[Cybernoid]

Nice. I could use a nice tektronics logic analyzer...

[remowilliams]

warerat, on Mon Jan 8, 2007 11:13 PM, said:

Status update. Some progress-- I got some signs of life, but display is garbled. You can see the 800 6502 jumping to the reset vector and running the code from the XL OS.

Stay tuned.

Cool

That is a sweet setup there

[FastRobPlus]

Any updates on this? It's my favorite A8 project.

[Ralphy Rocket]

Cool Tools!

[mimo]

any updates?

[MEtalGuy66]

mimo, on Tue Oct 2, 2007 5:27 PM, said:

any updates?

DO a search. Theres a much newer thread for this.

As far as updates, Warerat is still considering the possibility of a production "plug in" board which takes the place of the "personality board" in the 800. Unfortunately, the end cost of such a unit would depend heavily on the price/availability of cheap 512k SRAM chips.

The project has not been "dead" by any means.. At least 3 fully functional 576k XE compatible 800s (done by Warerat) are currently in use by users of this forum. However, I dont think he particularly fancys the idea of "blue-wiring" a custom board for each person who wants one. This is why he is considering a production run of boards. For the last 2 semesters, he has been very busy with night classes (in addition to his full time job) towards his masters degree in engineering.

I'll leave any further comments to him. He is still quite active on this forum...

[mimo]

thanks for the news.

[warerat]

mimo, on Wed Oct 3, 2007 3:05 AM, said:

thanks for the news.

I haven't forgotten. I'm done with the education thing now so I can dedicate some time back to this. I have a quasi-working single-board "personality module" that replaces all the RAM modules and the stock OS module.

Now I just need to pull the thing out of mothballs, and look at all my notes again to see how I ever got this to work at all.

[mimo]

put me on any list that there may be for one, maybe 2 if you can make it happen for the 400
good luck

[tjlazer]

Cool, a Plug'N Pray board would be awesome indeed! That way it can easily be reverted to a stock 800 correct?