Axlon RAM on an Incognito 800

[Britishcar]

I feel like I can do just about anything Atari related on the Incognito 800 thanks to its beautiful engineering! One thing that has me stumped, though, is the Axlon emulation when in Coleen mode.

 

When in XL/XE mode, one can choose Stock Config, 320K RAMBO, 576K CompyShop or 1088K RAMBO. You can also choose stock OS's, Fastchip, etc. Very tidy.

 

However, in Coleen mode, you choose Base Memory first: 16K, 32K, 48K or 52K. Then of course, you can choose your OS such as Stock A, Stock B, A-Fastchip, B-Fastchip etc.

 

Also in Coleen, there is the option of choosing "Axlon Emulation" Enabled/Disabled but with no amount of memory option, etc.

 

So my questions are:

 

1) Do you need to choose 48K or 52K for this to work properly? (Doesn't the Axlon extended RAM bank into the "unused" 4K at $C000 to $CFFF?)

 

2) Does turning on "Axlon Emulation" automatically assume 1meg of Axlon extended RAM? (And should I have the base RAM set to 48K or 52K to do this?)

 

For example, I can't get Top-Dos 1.5 to recognize any Axlon behavior in my Incognito 800 despite my goofing around with these settings. Top-Dos will enable Axlon mode but then flips out when I try to access it's RAMdisk at D8:.

 

Any Incognito experts have any advise for me?

[Rybags]

AFAIK the Axlon expansion actually uses $4000-$7FFF to bank in the extra RAM, as per the 130XE but the banking register is $CFFF instead of PORTB/$D301.

 

Which config? I'd give 48K a try first. A particular DOS not recognising it mightn't mean it's not right as many RamDisks only work on certain memory configurations to begin with.

[Britishcar]

Thank you, Rybags. After further futzing around, I've discovered that 52K plus Axlon in Incognito freaks Top-Dos out.

 

However, going into 48K plus Axlon, I can finally get Top-Dos to create an 883 sector RAM drive (what it defaults to).

 

BUT, despite showing 883 "sectors" of RAM available, it fails when trying to copy any file greater than about 40 sectors long (about 5K?).

 

So....as long as you stay under about 5K of RAMdiisk, it works, otherwise, pffffttt. I suppose it's only staying in the original 4K area or so and not banking out to extended RAM.

 

Dunno...if anyone else is trying to use Coleen/Axlon in an Incognito, please let me know!

 

Again, thank you for the advise, Rybags.

[Rybags]

Strange - it's my understanding Axlon did 16K blocks overlaying $4000.

There's other expansions around that do banking of 4K at $C000. 5K limit is weird in itself for the copying.

 

Possibly 52K confuses it with Axlon enabled as well. I'd assume that means a flat 52K with the Axlon selectable @ $4000, possibly the Dos thinks 52K available means there's bankable memory @ $C000.

[Britishcar]

Rybags, you're correct. I've been reading more about the Axlon memory scheme. It does use 16K blocks at $4000, etc.

 

I've now tried MYDOS 4.53 which sets up RAM drives fairly easily. It will set up a huge RAM disk in XL/XE mode, format it and write to it.

 

When I set up a RAM drive in Coleen 48K, Axlon mode, MYDOS will set up the drive, format it but the moment you copy anything to it, MYDOS freezes.

 

Again, the Incog may be functioning perfectly and I just am not aware of how much configuration is needed for Axlon use in most software or DOS environments...?

[Rybags]

Configuration is either auto, semi-auto or via some sort of parameter file. But that aside the DOS and/or it's Ramdisk handler has to be able to handle the many possible types of expanded Ram types that are around.

 

I've practically never used Top Dos, if you could find some decent documentation for it maybe it has mention of what it's able to handle.

[Britishcar]

Ok...this does seem to be a problem with my Incognito.

 

I've pulled up the same Top-Dos 1.5 ATR that I'm using on the 800/Incognito into Atari800MacX and set the emulator to Atari OS/B (Axlon Memory). Then I can enable an Axlon RAM drive, format it and copy files to it.

 

Using the same ATR, I set the Incognito to 48K, OS-B with Axlon emulation. Using the same Top-Dos procedure, it enables the Axlon drive, formats it but pukes (freezes) the moment I try to copy any files to it.

 

Does the Incog have a different sort of set up for Axlon memory when in Coleen (800) mode?

[candle]

it's hard to say for sure, but i'll give it a go when i'll have some kind of display for my atari here in warsaw

axlon was only tested with sdx, so i can't be really sure of anything

it would be a good thing if someone with psychical axlon expansion board would do the same test as you did

[BillC]

it's hard to say for sure, but i'll give it a go when i'll have some kind of display for my atari here in warsaw

axlon was only tested with sdx, so i can't be really sure of anything

it would be a good thing if someone with psychical axlon expansion board would do the same test as you did

I don't think AXLON made a RAM card over 256KB, but Magna Systems made 256KB/512KB/1MB Axlon compatible RAM cards.

[Britishcar]

Candle, thank you! I don't have a physical card for my 800 so I can't do a physical test, just the emulator test, etc.

 

If it helps with understanding what might be going on, I CAN create the drive, initialize the drive and then copy one or two very small files to it...but no more that 4 or 5K in size total.

 

Anything larger results in freezes or freakouts from the machine.

 

If anyone has a way to test an Axlon board, here is what I am doing in both emulation (Atari800MacX) and the Incognito 800:

 

1) Load up TOP-DOS 1.5 © 1985 R.K. Bennett without BASIC and set to base 48K (a very nice menu-driven DOS with lots of configurability and a nice help system)

2) Binary Load (L) the "AXLON" file on the TOP-DOS disk. It will say "Installing Axlon ramdisk ..." and "AXLON" will appear in your menu/status area.

3) Binary Load (L) the "IZRAMDISK" file on the TOP-DOS disk. It will then say "Initializing ramdisk"

4) You should have a single density 883 sector ramdrive 8: to work with -- depending on the size of your expansion card?

 

In emulation, this works great. On the Incog, it fails. Same ATR image for TOP-DOS.

[sup8pdct]

Try superdos 5.1. Part of its boot process is to load dup to the ram disk. If it freezes, there is a problem somewhere.

 

James