Atari 800 memory upgrade question

[Magic Knight]

Hi

 

Ive Just bought a stock Atari 800 and (after successfully retrobriting it up :0) ) am looking at what expansion options for memory?

 

After reading loads on here, can't seem to see if the Atarimax, The!Cart etc would allow the 48k unit to play games like dropzone or any of the 64k requirements with its onboard ram boosting it up.

 

Are these carts able to boost the memory or what add-ons or upgrades are currently available? (Besides the elusive incognito).

 

I'm open to modding 16k cards also if info available. :0)

 

(Sorry if this has been covered somewhere before)

[Rybags]

Normal small cartridges won't upgrade the system Ram although some do have Ram, often SRAM that can be battery backed and is more oriented towards software development.

 

Incognito is the top of the range for 800 Ram upgrades and gives XE compatability as well as 1 Meg Ram and other good stuff though I don't think there's any in production or for sale.

 

If you can aquire and mod 16K cards with confidence then that's probably your best bet.

[Magic Knight]

Normal small cartridges won't upgrade the system Ram although some do have Ram, often SRAM that can be battery backed and is more oriented towards software development.

 

Incognito is the top of the range for 800 Ram upgrades and gives XE compatability as well as 1 Meg Ram and other good stuff though I don't think there's any in production or for sale.

 

If you can aquire and mod 16K cards with confidence then that's probably your best bet.

 

Thanks

 

I did own a 800 around 4 years ago and fitted a first batch Incognito board, but had to sell the unit (along with other things) when i split with the wife. Top piece of kit the incognito and miss the brilliant setup i had.

 

 

Not sure why this is out of production and Lotharek doesn't still produce this on his store? (even while Incognito 2 is being developed i believe)

 

Anybody know that and any links to modding up a 64k (or 128k) board?

[+slx]

Unless you need a Ramdisk there isn‘t much Software that will take advantage of the Axlon-type RAM expansions. To make the 800 compatible with XL programs requiring >48K you need Incognito or something like the PIAMOD described on Mathy‘s http://www.mathyvannisselroy.nl/special%20stuff.htm

 

ClausB is the resident 400/800 RAM guru here and might have additional insights. I am more of a reader than solderer, so I have not tried any of this.

 

 

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[Magic Knight]

Unless you need a Ramdisk there isn‘t much Software that will take advantage of the Axlon-type RAM expansions. To make the 800 compatible with XL programs requiring >48K you need Incognito or something like the PIAMOD described on Mathy‘s http://www.mathyvannisselroy.nl/special%20stuff.htm

 

ClausB is the resident 400/800 RAM guru here and might have additional insights. I am more of a reader than solderer, so I have not tried any of this.

 

 

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Thanks, ill check this out,

[Magic Knight]

Also - Does anyone know if using 2 x 32k Intec Peripherals memory boards would actually work (64k total) - anyone tried this..?

 

Failing that ill try this - http://atariage.com/forums/topic/242691-atari-800-256kb-upgrade/

Edited November 14, 2018 by Magic Knight

[+tf_hh]

Also - Does anyone know if using 2 x 32k Intec Peripherals memory boards would actually work (64k total) - anyone tried this..?

 

Failing that ill try this - http://atariage.com/forums/topic/242691-atari-800-256kb-upgrade/

 

a.) Using an Atari 800 without Incognito or another heavy modification you can only access 48 (or 52KB with some hacks) memory at once. All other solutions require bank-switching. Without mods to the mainboard and personality cartridge the last 16 KB can´t access by RAM, even if you put a 64 KB RAM cart in. The old series (400/800) never include such mechanism like the XL/XE series.

 

b.) I´m quite sure that only one of the non-standard (i.e. 8 or 16 KByte) RAM carts works fine. And only in the middle slot, where all needed Sx select lines are availible

[Magic Knight]

 

a.) Using an Atari 800 without Incognito or another heavy modification you can only access 48 (or 52KB with some hacks) memory at once. All other solutions require bank-switching. Without mods to the mainboard and personality cartridge the last 16 KB can´t access by RAM, even if you put a 64 KB RAM cart in. The old series (400/800) never include such mechanism like the XL/XE series.

 

b.) I´m quite sure that only one of the non-standard (i.e. 8 or 16 KByte) RAM carts works fine. And only in the middle slot, where all needed Sx select lines are availible

 

Thanks,

 

Ill ploughed through the web this morning and cant believe the amount of mods made for taking the 800 to capacities from 64k all the way up to 512mb and they've all been on small runs and/or unavailable.

 

Ive looked through the refined Jerzy Sobola mod (256k) and am going to knock up a gerber file on Eagle for manufacture. If it works, ill post some pictures and stuff here. :0)

[Gunstar]

I also find myself in the predicament of recently receiving an 800 as a gift and am currently getting ready to retro-brite it too, change out the capacitors and do the miner cartridge ports mod so The!Cart and MyIDE 2 will work with it (up to 48/52K of course). I'm also hunting for an Incognito, for the right price. Or the possibility of an Axlon ram upgrade in the meantime. I think it's the Mosaic 64K/128K boards for the 800 that gives you 52K of main memory and the rest is banked. I'm not sure if any Axlon originals gave you more than 48K of main memory, I'll be looking into it though.

 

If I remember correctly the extra 4K in the 52K memory is mapped under the OS, similar to XL/XE's 16K. But I don't know if, for example, the extra 4K is mapped to the same locations as the first 4K of XL/XE's 16K under the OS or not. If it were, that might mean there are some programs out there that are said to require 64K, but might in fact just require more than 48K, but maybe would fit within 52K of 800 ram?

 

Though in my recent quest to find out all the legacy software that uses the XE and/or Rambo standards of memory upgrades to take advantage of my 576K 1200XL, I have found out more software than I knew also takes advantage of the Axlon banking scheme. Probably everyone knows of the Synapse Syn-series productivity sofware that uses both Axlon and XE/Rambo upgrades, but I also have found XLEnt Software's desktop publishing series of interconnected programs also takes advantage of Axlon memory and other word processors and whatnot.

Edited November 14, 2018 by Gunstar

[Gunstar]

From looking at the 400/800 memory upgrade faq on Atarimania, it seems the extra 4K in 52K memory upgrades is continuous, right after the first 48K so it should be compatible with the first 4K of XL/XE 64K memory, which if I'm understanding correctly only 62K of which is really available. This is stuff I remember reading about before, but just forgot.

Edited November 14, 2018 by Gunstar

[+slx]

The 52K adds RAM from C000 to CFFF which is unused on the 400/800 (unless you have Omnimon installed). You can use that space for machine language subroutines, display lists, character sets, etc. at the expense of making your program unusable on the 99,5% of machines that don't have RAM there. So it's more of a "because it can be done" mode (which on a larger scale one could say about any mod to a 30+ year old computer).

 

I found a better description of the second PIA here but it still requires a mod (to the ROM board?) allowing dual original and XL ROMs and a RAM mod allowing the new PIA to switch RAM in the same windows the XL does.

 

The 62 vs 64 is probably due to the RAM that would be mapped to the register space at D000 to D7FF which AFAIK can't be used (as the registers must be "visible" all the time). I only had a plain 48K 800 BITD so all this bank switching is still a bit hard to fully wrap my mind around.

[Gunstar]

The 52K adds RAM from C000 to CFFF which is unused on the 400/800 (unless you have Omnimon installed). You can use that space for machine language subroutines, display lists, character sets, etc. at the expense of making your program unusable on the 99,5% of machines that don't have RAM there. So it's more of a "because it can be done" mode (which on a larger scale one could say about any mod to a 30+ year old computer).

 

I found a better description of the second PIA here but it still requires a mod (to the ROM board?) allowing dual original and XL ROMs and a RAM mod allowing the new PIA to switch RAM in the same windows the XL does.

 

The 62 vs 64 is probably due to the RAM that would be mapped to the register space at D000 to D7FF which AFAIK can't be used (as the registers must be "visible" all the time). I only had a plain 48K 800 BITD so all this bank switching is still a bit hard to fully wrap my mind around.

This is what I originally thought, that the 4K wouldn't be compatible with XL/XE 16k under the OS. But after reading some memory upgrade faqs, which where saying it was continuous, right after the first 48K, I thought that meant compatible. I should have cracked my Mapping The Atari book and checked those memory locations...

 

Thanks!

 

I think I'm going with one of these DIY 800 Axlon compatible project too, as I doubt I'll be able to get an incognito anytime soon. And now is good a time as any, with my 800 in pieces for a retro-brite and new caps and cartport mod to use MyIDE 2 and The!Cart anyway...

[ClausB]

This mod gives 62K:

http://atariage.com/forums/topic/185500-using-the-atari-400-48k-board-in-the-800/page-2?do=findComment&comment=2731076

[ClausB]

Someone asked about 2 32K boards. They could be modded to give 62K, or they could be modded to give 160K, Axlon style. BITD I turned a 32K board into a 128K board:

http://atariage.com/forums/topic/122750-64k-atari-800/?do=findComment&comment=1676834

[adamchevy]

If only we could get another run of incognito boards. I had an opportunity to buy one but stupidly passed it up. I would commit to 2 of them this time.

[Gunstar]

This mod gives 62K:

http://atariage.com/forums/topic/185500-using-the-atari-400-48k-board-in-the-800/page-2?do=findComment&comment=2731076

This one being XL compatible is going to give the 800 a lot more "64K" games, depending on what "sort of" means in that post. It might be tough for me to choose between this one and an Axlon compatible for more than 62K. If only I could have my cake and eat it too! Maybe I could rig it to switch between a couple upgrades. It looks like I'd need to find a 400 48K board for the job. I've got 3 16K boards, is there a 62K or Axlon upgrade that can be made using 2 or 3 of them? I'm willing to dig deep and get my hands dirty. If I ever get an Incognito, I'm going to make a real PBI out the back of the 800, just so you know how dirty I'm willing to get. A-1 technician here, just not a full-fledged engineer with the where-with-all to design my own Incognito.

 

Edit: I think I messing up the two threads you pointed too, the "sort of" comment was in the other one...

Edited November 15, 2018 by Gunstar

[ClausB]

Yes you could start with a 16K board instead of 48K, but it would take more work. You would have to reroute the power traces (look at my old 48K 400 instructions: http://atariage.com/forums/topic/123207-expanding-the-400/#entry1488304) and add the extra gates per the schematic.

Edited November 15, 2018 by ClausB