Extended memory&8-bits

[Gunstar]

I've decided to start a new topic on extended memory 8-bits that started in my '1200XLE' thread, so maybe more people could add to the discussion, that they may have missed it, as it was included in the other thread. let me bring everyone up to speed, so there's no need to review the '1200XLE' thread.

 

A reply from remowilliams in the '1200XLE' thread mentioned a problem with the RPG game Alternate Reality: The Dungeon, which is capable of using extended memory of at least a standard 130XE. Remowilliams said that his upgraded 1200XL (Rambo XL-256k) "...doesn't work properly with the extra memory..." I thought I had noticed a difference too, from my 130XE(pre-320K upgrade, i.e. standard 128K) and my Ramo XL upgraded 1200XLE. But it had been a long time since I had played the game on the XE, so I wasn't positive about the differences in memory usage between the two machines.

 

@remowilliams; Does AR:D report 128k at game boot-up on your 1200? Or 64K?

 

I did some further memory studying of both my 1200 and 130. Using AR: D game first, I noticed that on both the 1200 and 130 that the program worked exactly the same, from the boot where it recognized at least 128k of memory in both machines; "128k memory initilization" is what it says after checking on computer&memory type. Then in-game they work exactly the same with disk&memory access. Now, from my memory (mine, not the computers) it works differently than a standard 130XE in that it doesn't seem to load as much into and from memory. Of course I asked, and am asking for someone who has a standard 128k 130XE to test AR:D on their computer to see if it will load multiple dungeon sections into memory or not, since I no longer have an unmodified 8-bit to test with AR:D.

 

Now, I also tested my 256k 1200 and 320k 130 with a demo program called 'Cyberspace XE' which is just a 'Movie Maker' movie that uses extended ram as a ramdisk. This program specifically recognizes and reports what type of Atari 48k+ computer you have. It recognized my 1200 as a "800/1200XL 256K" and my 130 as a "320XE 320k." So it appears my computers are recognized properly, and are working as they should. What does this mean with AR: Dungeon? Well, AR:D as I stated, recognizes at least 128k of memory on these machines, but then doesn't seem to use it anyway (yet to be proved with a control test on a standard 130XE 128k). If this is the case, why doesn't it use the extra memory? Even just 128k of it? It recognized at least 128k of memory.

 

My memory upgrades are recognized and used as they should be with other programs, it seems to prove to me that the 320K 130 is still working just like a standard 130 (including ANTIC compatibility with the memory) and the 1200 is recognized and used as a proper Rambo XL upgrade that is not ANTIC compatible. So if there where a problem with AR:D's memory use, one would think it would still work properly with my 130, but not the 1200. But it seems to recognize BOTH as a 128k XE and then not use it properly...

 

Does Alternate Reality: the Dungeon not expect to find MORE than 128k and when it does, refuses ALL extended memory and revert back to 64k? If so WHY? If this is the case, if it ignores all extended ram if it sees more than 128k, then why would the program report back that it's a 128k machine instead of a 64k machine like it does on a standard XL? There IS more at stake here! It could be a VERY important bit of information in reagards to the on-going conversion of AR games to Flash cartridge from disk. I'd be curious to know how Atari emulators and AR:D use memory too...

Edited July 27, 2006 by Gunstar

[Wilheim]

Gunstar,

 

IIRC, during the AR: D program, after the title demo and before the "XX Kb Memory Inicialization", you can force to initialize it with 48k RAM, just by pressing SELECT. You will notice the differences between 48 and 128 kb RAM. 48 and 64kb initializations are almost the same.

 

Try it to test.

 

(sorry, I forgot to tell what key is pressed)

Edited July 27, 2006 by Wilheim

[Wrathchild]

Thanks for raising this - by using the cart, the need for actually using the extra memory is made redundant as the access to the cart is fast enough, i.e. the extra memory is a just cache, so the data that is required is copied to the working RAM anyway.

 

Looking at the code for the Dungeon, if the check is done solely at startup then what I'd recommend (and will most likely be doing for the FlashCart version), is to bypass the over 64K check. So 48K machines work without using the memory under the ROMs and all others can. It maybe OK even to get ALL systems to use the 48K model as the overheads are not worth worrying about? But so long as all >64K memory models work correctly with the PORTB access it can see leaving that in being a problem either?

 

For the issue described above, a recommendation would be to hack

the few bytes required in the startup to go into 64K mode.

 

Regards,

Mark

[Gunstar]

Well, if you can force it to 48k, I don't know how, and I have all the original documentation for the game and it doesn't mention this anywhere that I can find. Also, the difference between 48k and 64k initilization is far more extensive than you realize. I recently sold a 48k 800 and just recently upgraded my 1200, and had recently tested the difference between 48k and 64k, and it is significant, blatantly obvious in load times and how often the disks are accessed. I just don't recall the difference between 64&128k. If you can tell me how to force a 48k load I would appreciate it and compare again to my upgraded system to see if they are at least using 64k; this seems to be obvious to me after trying it on the 800, but I'd like to be totally sure. What I will try is using the original 800 OS in my 32-in-1 OS to see if that forces a 48k load.

[Wilheim]

Ooops, I didn't tell how to force the 48kb initialization. Press and maintain SELECT during the load between the title demo and the memory initialization.

 

To be honest, I didn't notice the difference with 48 and 64kb with this game in particular. But I noticed the difference between 64kb and 128kb, mainly because in 128kb it uses the extended RAM as a cache of encounters, some places and maps.

[Gunstar]

Thanks for raising this - by using the cart, the need for actually using the extra memory is made redundant as the access to the cart is fast enough, i.e. the extra memory is a just cache, so the data that is required is copied to the working RAM anyway.

 

Looking at the code for the Dungeon, if the check is done solely at startup then what I'd recommend (and will most likely be doing for the FlashCart version), is to bypass the over 64K check. So 48K machines work without using the memory under the ROMs and all others can. It maybe OK even to get ALL systems to use the 48K model as the overheads are not worth worrying about? But so long as all >64K memory models work correctly with the PORTB access it can see leaving that in being a problem either?

 

For the issue described above, a recommendation would be to hack

the few bytes required in the startup to go into 64K mode.

 

Regards,

Mark

 

Thanks Wrathchild, I did think about the redundancy in extended ram with the flashrom, but thought it important to mention as possible code that may have to be looked inti, or, at least, those looking might be able to see exactly how it checks for extra memory to enlighten us all, e.g., possibly it checks for multiple memory configurations like 800 AXLON as well as XL Rambo, XE, etc. I know that Philip Price used 128k (presumably AXLON) upgrade 800 when programming THE CITY, and the rumor is that it checks for more than 48k too, and I definately notice a difference with THE CITY and 48k&64k atari's, but not as much with the XE's 128k, BUT, it could be that anything beyond 64k with THE CITY is only looking for AXLON compatible and therefore would not recognize an XE's 128k. I'd like to know how similai/dissimilair THE CITY&DUNGEON are in memory checks since THE DUNGEON does recognise 48, 64 and at least 128k XE...does it recognize AXLON memory too? It appears to recognize RAMBO memory, but to what extent is the question. With this knowledge it might make it possible for others to hack the code to include ALL types of memory upgrades, to take full advantage without a flashcart, just using real disks and upgraded computers, or SIO2PC&computers or even to get the most out of the game with and emulator. I don't expect you to be concerned with memory upgrades while working on a flashcart conversion, but maybe you have to come across it in your work and can pass on the info, or, maybe it wouldn't take much to hack yourself, and you'd be willing to do it for hacker glory or something to give the community while waiting on your flashcart version, if it's not too hard a hack...

 

KEY:

AXLON-original 800 extended memory standard. 128k or 256k swapped in 8k blocks.

RAMBO-new extended memory standard for XL models(XE compatible in CPU mode only). 256K swapped in 16k blocks.

130XE-Official Atari extended memory standard with CPU&ANTIC compatibility. 128k+ swapped in 16k blocks.

Edited July 27, 2006 by Gunstar

[ijor]

What I will try is using the original 800 OS in my 32-in-1 OS to see if that forces a 48k load.

 

Are you using the original or a crack?

 

Many protections check both the OS and the hardware. So using the original OS-B ROM might be not enough for getting exactly the same behavior as in a true 800 computer. As a matter of fact, some protections will break and won't run at all if you attempt to use the OS-B or OS-A ROM in an XL computer.

 

I have no idea if this is affecting The Dungeon or not. If it does, it might affect even a crack.

[Gunstar]

Ooops, I didn't tell how to force the 48kb initialization. Press and maintain SELECT during the load between the title demo and the memory initialization.

 

To be honest, I didn't notice the difference with 48 and 64kb with this game in particular. But I noticed the difference between 64kb and 128kb, mainly because in 128kb it uses the extended RAM as a cache of encounters, some places and maps.

 

OK, I tested it out in 48k mode by forcing it with the select button. I also took it a step further, figuring that if there is a 48k "force" why wouldn't there be a 64k "force" as well? I was right! There is a 64k "force" by copying your 48k "force" but holding down OPTION in between the opening sequence and memory initilization instead of SELECT. First off, The 48&64k difference with the dungeon is not as drastic as I thought I recalled, I believe I had this confused with the city game. But, there is a difference; while it does seem to load constantly like the 48k version, it does seem to be shorter load times, so I figure it must be using the extra 16k ram as a "cache" of sorts. Now, in 128k mode the program is indeed recoginizing and using more than 64k and it shows by instant loads from extra memory all over the place and much less frequent and shorter disk load times, BUT, it still doesn't seem to be loading the dugeon MAPS into extended memory like it does on a standard 130XE (still need this verified on an unmodified 130XE), the load times are just as long and frequent between 64k mode and 128k mode when going between map sections appears. So extra memory is definately used with both of my upgrades, but not as efficiently as with a standard 130XE(again, still need verification on map loading).

[Gunstar]

What I will try is using the original 800 OS in my 32-in-1 OS to see if that forces a 48k load.

 

Are you using the original or a crack?

 

Many protections check both the OS and the hardware. So using the original OS-B ROM might be not enough for getting exactly the same behavior as in a true 800 computer. As a matter of fact, some protections will break and won't run at all if you attempt to use the OS-B or OS-A ROM in an XL computer.

 

I have no idea if this is affecting The Dungeon or not. If it does, it might affect even a crack.

I'm using original disks for the tests, not cracks. But instead of using OS-B, I just used the "force" options spoken of above to test 48/64/128k modes. Quite handy, I didn't know they existed! I still need verification on my standard 128k XE assumptions though, to know for sure if XE XMS is used differently from XL XMS.

 

I also still need remowilliams to expand on his original statement that his RAMBO XL upgrade isn't working properly with AR:D, as I've now proven that RAMBO does use memory beyond 64k with AR:D AND my 320K XE upgrade uses it exactly the same. I need to know if he sees the 128k initilization or a 64k one, he may not have his RAMBO jumpers set correctly. There are 3 jumpers on the RAMBO board that are to be set differently for the different XL models. I also still want to know for sure if AR:D uses 800 AXLON memory as I've been told AR:C does. For sure AR:C uses 48k and 64k modes, but it's assumed, I think, that it used AXLON memory since Philip Price used an AXLON memory 800 to program it. I haven't ever gotten verification on this myself, I couldn't find an Axlon memory upgrade for my 800 when I had it, so I was never able to test this out on either game.

Edited July 27, 2006 by Gunstar

[+remowilliams]

I also still need remowilliams to expand on his original statement that his RAMBO XL upgrade isn't working properly with AR:D, as I've now proven that RAMBO does use memory beyond 64k with AR:D AND my 320K XE upgrade uses it exactly the same.

Well I hooked her up to verify - and I was wrong.

 

It does initialize at 128K. The issue I had with AR:D on this machine is that it doesn't work at all and I could never figure out why.

 

It will load the intro, initialze and get to the point where it should display the initial selection screen. Instead it just keeps asking me to insert Disk 1. I tried using APE with cracked images (Heist and Homesoft), a .PRO boot image, and the original disk in my Indus - and they all do exactly the same thing. Though it loads other protected software fine, from .PRO images, originals or the VAPI loader I'm testing.

[Gunstar]

I also still need remowilliams to expand on his original statement that his RAMBO XL upgrade isn't working properly with AR:D, as I've now proven that RAMBO does use memory beyond 64k with AR:D AND my 320K XE upgrade uses it exactly the same.

Well I hooked her up to verify - and I was wrong.

 

It does initialize at 128K. The issue I had with AR:D on this machine is that it doesn't work at all and I could never figure out why.

 

It will load the intro, initialze and get to the point where it should display the initial selection screen. Instead it just keeps asking me to insert Disk 1. I tried using APE with cracked images (Heist and Homesoft), a .PRO boot image, and the original disk in my Indus - and they all do exactly the same thing. Though it loads other protected software fine, from .PRO images, originals or the VAPI loader I'm testing.

Do you know for sure that your RAMBO jumpers are set for a 1200XL instead of an 800XL? It may not have anything to do with your problem, but it's possible. Also, I use 1050 drives, but I am going to be getting a working Indus drive from a friend on Saturday, so I will be able to test it with that to verify or eliinate your Indus from the problem you are having. I do recall having problems with cracked versions, though don't remember exactly what. The cracked city disks seem to work properly, but not cracked dungeon disks. In both cases the game writes to multiple disks throughout gameplay, and you MUST use the same disks with the same character disk. Mixing them up with other copies leads to many problems and crashes. But I don't recall for sure if this would effect disk 1 side 1 at all, but it does effect other sides. Since you have tried cracked images, pro images and originals I think it must be either a disk drive problem or a memory problem like Rambo jumper settings. If you had ONLY tried cracked versions, I would have blamed them.

Edited July 27, 2006 by Gunstar

[Gunstar]

Has anyone been able to test a standard 130XE with Alternate Reality the Dungeon yet? To see how it handles the extra memory and loading times&frequency? I still think that RAMBO XL and 320XE upgrades use the 128k memory differently than a standard 128k 130XE. But I don't recall for sure. Mainly as far as keeping multiple dungeon map areas in memory or if there is still access to the disk.

[MEtalGuy66]

Has anyone been able to test a standard 130XE with Alternate Reality the Dungeon yet? To see how it handles the extra memory and loading times&frequency? I still think that RAMBO XL and 320XE upgrades use the 128k memory differently than a standard 128k 130XE. But I don't recall for sure. Mainly as far as keeping multiple dungeon map areas in memory or if there is still access to the disk.

 

I just tested it on 3 systems: a bone stock 800XL, a bone stock 130XE, and a (Scott petersen upgrade) 320XE. Theres definitely a difference between 64k and 128k operations. As far as the difference between the 320xe and stock 130xe, if there is one, its so negligible that I can't notice it at all. Both initialize as "128k."

 

I would suspect that any 16k bank-scheme extended RAM setup for the XL/XE would be recognized and act the same, assuming also that it uses the same PIA bits for bank select of the FIRST extended 64k as a 130XE (which RAMBO does.)

 

The game definitely doesnt use separate ANTIC and CPU access to extended ram, so 100% 130xe compatability should not be an issue. The RAMBO style upgrades should work fine.

Edited August 24, 2006 by MEtalGuy66