Checking for alt-ram ?

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Checking for alt-ram ?

Postby exxos » Thu Jan 07, 2016 1:32 pm

How does one go about checking if a machine actually has alt-ram installed or not ?

My initial thought was just trying to allocate a huge chunk of memory and see if it can reserve a large enough chunk that it must have alt-ram, but that idea seems pretty bad. Under emulation in steem where it has 14MB STRAM that idea would fail.

So assume there is some "proper" method to get the amount of alt-ram installed on a machine ?

Also some method to work out if a program was run in alt-ram or ST-ram?
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Re: Checking for alt-ram ?

Postby Cyprian » Thu Jan 07, 2016 2:11 pm

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Re: Checking for alt-ram ?

Postby mfro » Thu Jan 07, 2016 2:21 pm

You can safely assume that alternate RAM is available if the _FRB cookie is set. This conclusion is not necessarily true the other way round, however.

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Re: Checking for alt-ram ?

Postby exxos » Thu Jan 07, 2016 2:27 pm

mfro wrote:You can safely assume that alternate RAM is available if the _FRB cookie is set. This conclusion is not necessarily true the other way round, however.


I did see that a couple hours ago, though it appeared it was only for the Magnum alt-ram board. So we a little wary about using it as wasn't sure what was being set by what with it all.



I just found that in fact :) Though I assume it returns zero if it fails to allocate memory, as in, doesn't exist. It doesn't actually say what a "fail" code is.

Return value: The function returns the start address of the reserved block as an untyped pointer. Mxalloc returns a 0 when insufficient memory is available.
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Re: Checking for alt-ram ?

Postby dml » Thu Jan 07, 2016 2:35 pm

You can call Mxalloc and ask for 'TT ram only' and it will return 0 if there isn't any. You can then keep the memory, or free it again (if you're just trying to detect its presence). This is probably the least intrusive way to check for its presence. The next level down is cookies, and below that it gets very nasty.

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Re: Checking for alt-ram ?

Postby Cyprian » Thu Jan 07, 2016 2:42 pm

ok, _FRB looks more adequate
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Re: Checking for alt-ram ?

Postby mfro » Thu Jan 07, 2016 2:50 pm

exxos wrote:I did see that a couple hours ago, though it appeared it was only for the Magnum alt-ram board. So we a little wary about using it as wasn't sure what was being set by what with it all.


Atari ST-compatible custom chips can only deal with memory within the first 16 MB of RAM. TT alternate RAM starts at $1000000 (which ACSI-DMA, for example, is unable to reach). For GEMDOS to be able to read file contents into alternate RAM (or write from it), the _FRB buffer is mandatory. So if it's there, you have alt RAM.

Mxalloc() (as well as Malloc()) returns the largest available amount of memory if called with a -1 argument. But you first need to know if Mxalloc() is available at all (GEMDOS version).

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Re: Checking for alt-ram ?

Postby exxos » Thu Jan 07, 2016 3:06 pm

I see TOS104 is GEMDOS V0.21 though AFAIK only TOS206 supports ALT-RAM anyway ? If thats the case, then I should just check for alt-ram over TOS206 versions.

Though for some reason its causing a stack overflow not sure why :( I have the same problem when trying to open a popup form (basic message with yes/no type input) which I haven't figured out yet. I've tried increasing the stack size but it just takes a second longer to crash. So not really sure why its throwing a wobbly :(

EDIT1:

LMAO..

Code: Select all

FUNCTION CHECK_ALTRAM&
CHECK_ALTRAM&=mxalloc&(2,&h010)

OPEN "DEBUGRAM.TXT" for OUTPUT AS #2
print #2,CHECK_ALTRAM&
close #2

END FUNCTION



I think you have to be a bit clever to work out why that one fails :lol:
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Re: Checking for alt-ram ?

Postby mfro » Thu Jan 07, 2016 3:16 pm

exxos wrote:I see TOS104 is GEMDOS V0.21 though AFAIK only TOS206 supports ALT-RAM anyway ? If thats the case, then I should just check for alt-ram over TOS206 versions.


TOS 1.04 has GEMDOS version 0.15. See the description of the GEMDOS Sversion() system call in TOSHYP.

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Re: Checking for alt-ram ?

Postby exxos » Thu Jan 07, 2016 3:20 pm

mfro wrote:
exxos wrote:I see TOS104 is GEMDOS V0.21 though AFAIK only TOS206 supports ALT-RAM anyway ? If thats the case, then I should just check for alt-ram over TOS206 versions.


TOS 1.04 has GEMDOS version 0.15. See the description of the GEMDOS Sversion() system call in TOSHYP.


Something amiss somewhere then, as Gembench reports 0.32 for TOS206, then when I switch over to TOS104 it reports 0.21, and TOS1.02 v0.19. Then in sysinfo TOS1.02 reports V0.13 :roll:

I'm actually using Sversion, so not sure why its coming up wrong values.
Sversion reports "21" for TOS104, but sysinfo says "0.15" :shrug: :shrug: Is there any other way to get the version number ?

The return number I get from mxalloc is "-32" :shrug:
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Re: Checking for alt-ram ?

Postby exxos » Thu Jan 07, 2016 4:14 pm

A small thought relating to Sversion... if I am getting 21, then hex is 15 which would match what sysinfo says for TOS104.

TOS206 I get 32, which is 20 in hex. So this is probably where the confusion is coming from :roll:

I'm reporting in DEC format, and everywhere else seems to be outputting the value in HEX ?!
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Re: Checking for alt-ram ?

Postby Cyprian » Thu Jan 07, 2016 4:22 pm

mfro wrote:Atari ST-compatible custom chips can only deal with memory within the first 16 MB of RAM. TT alternate RAM starts at $1000000 (which ACSI-DMA, for example, is unable to reach). For GEMDOS to be able to read file contents into alternate RAM (or write from it), the _FRB buffer is mandatory. So if it's there, you have alt RAM.

Mxalloc() (as well as Malloc()) returns the largest available amount of memory if called with a -1 argument. But you first need to know if Mxalloc() is available at all (GEMDOS version).


In case of Atari ST Alt-Ram starts from $40000. From all ST chips only BLiTTER have access to full 24bit address range and have access to ALT Ram. The rest of chips see only first 4MB Ram.

exxos wrote:I see TOS104 is GEMDOS V0.21 though AFAIK only TOS206 supports ALT-RAM anyway ? If thats the case, then I should just check for alt-ram over TOS206 versions.

If I'm not wrong in case of 1.x TOS version, when user would like to use ALT-Ram, should install (in AUTO folder) appropriate application which install "_FRB" cookie and provides needed MxAlloc function.
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Re: Checking for alt-ram ?

Postby mfro » Thu Jan 07, 2016 4:24 pm

exxos wrote:I'm reporting in DEC format, and everywhere else seems to be outputting the value in HEX ?!


That's what TOSHYP misses to tell you: Sversion() return values are BCD coded.

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Re: Checking for alt-ram ?

Postby exxos » Thu Jan 07, 2016 4:31 pm

mfro wrote:
exxos wrote:I'm reporting in DEC format, and everywhere else seems to be outputting the value in HEX ?!


That's what TOSHYP misses to tell you: Sversion() return values are BCD coded.


That explains that then. Seems the original author of Gembench got caught out with that aswell then as I copied his routine :lol:

Cyprian wrote:
exxos wrote:I see TOS104 is GEMDOS V0.21 though AFAIK only TOS206 supports ALT-RAM anyway ? If thats the case, then I should just check for alt-ram over TOS206 versions.

If I'm not wrong in case of 1.x TOS version, when user would like to use ALT-Ram, should install (in AUTO folder) appropriate application which install "_FRB" cookie and provides needed MxAlloc function.


Thats worth looking into then. I've ordered a monster from Alan to use on my STFM, without TOS206 I thought it would be unusable. So the question is, what software and where to download it from..
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Re: Checking for alt-ram ?

Postby Cyprian » Thu Jan 07, 2016 4:36 pm

from his page:
http://www.atarikit.co.uk/
"NEW: The MonSTer board - Dual IDE/8MB RAM/FlashTOS" --> "The ALT-RAM program"
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Re: Checking for alt-ram ?

Postby exxos » Thu Jan 07, 2016 4:46 pm

Cyprian wrote:from his page:
http://www.atarikit.co.uk/
"NEW: The MonSTer board - Dual IDE/8MB RAM/FlashTOS" --> "The ALT-RAM program"


Ahh, well I thought it was the program to set the flags to load stuff in alt-ram, so I never looked into it any more than that :cheers:

On that basis, checking for GEMDOS version isn't going to work, so will have to use the cookie method it seems.
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Re: Checking for alt-ram ?

Postby exxos » Thu Jan 07, 2016 5:02 pm

The _FRB cookie reports "-1" in steem, there doesn't seem to be any clue what returned values are supposed to be and what they mean :shrug:

I assume it means the cookie is there but no alt-ram ? and if it found alt-ram it would report some number instead ?
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Re: Checking for alt-ram ?

Postby Cyprian » Thu Jan 07, 2016 5:26 pm

yep,
Currently Steem and Hatari doesn't support ALT-Ram. It seems that they 'hacked' emulated hardware to support full 14MB ST-RAM.
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Re: Checking for alt-ram ?

Postby exxos » Thu Jan 07, 2016 5:38 pm

Cyprian wrote:yep,
Currently Steem and Hatari doesn't support ALT-Ram. It seems that they 'hacked' emulated hardware to support full 14MB ST-RAM.


I think that was talked about breafly in another thread a few days go somewhere.


Anyway, so the cookie part should be working fine now. Though how to I now check if the program itself was executed in alt-ram ?
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Re: Checking for alt-ram ?

Postby npomarede » Thu Jan 07, 2016 9:36 pm

Cyprian wrote:yep,
Currently Steem and Hatari doesn't support ALT-Ram. It seems that they 'hacked' emulated hardware to support full 14MB ST-RAM.

Nope, Hatari supports alt-ram for Falcon and TT mode since Hatari 1.9, which was quite a lot of changes to handle, as this requires 32 bit support in memory access thus a 68030 cpu, and not a 68000.

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Re: Checking for alt-ram ?

Postby npomarede » Thu Jan 07, 2016 9:43 pm

Cyprian wrote:
mfro wrote:Atari ST-compatible custom chips can only deal with memory within the first 16 MB of RAM. TT alternate RAM starts at $1000000 (which ACSI-DMA, for example, is unable to reach). For GEMDOS to be able to read file contents into alternate RAM (or write from it), the _FRB buffer is mandatory. So if it's there, you have alt RAM.

Mxalloc() (as well as Malloc()) returns the largest available amount of memory if called with a -1 argument. But you first need to know if Mxalloc() is available at all (GEMDOS version).


In case of Atari ST Alt-Ram starts from $40000. From all ST chips only BLiTTER have access to full 24bit address range and have access to ALT Ram. The rest of chips see only first 4MB Ram.

mfro is right, alt ram (also called fast ram on TT) starts at $100000, not at $40000 as you suggest.
This is why blitter/fdc/hdc can't transfer data directly to alt RAM, and that's also why the CT60 for example came with a patched tos that redirected lots of OS calls to works in 32 bit mode.

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Re: Checking for alt-ram ?

Postby exxos » Thu Jan 07, 2016 10:01 pm

npomarede wrote:Nope, Hatari supports alt-ram for Falcon and TT mode since Hatari 1.9, which was quite a lot of changes to handle, as this requires 32 bit support in memory access thus a 68030 cpu, and not a 68000.
Nicolas


Oh wow, that is awesome, I only updated to 1.9 about a hour ago and not seen that option yet :)

EDIT1: the arrows don't seem to change it from N/A :?
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Re: Checking for alt-ram ?

Postby npomarede » Thu Jan 07, 2016 10:22 pm

exxos wrote:
npomarede wrote:Nope, Hatari supports alt-ram for Falcon and TT mode since Hatari 1.9, which was quite a lot of changes to handle, as this requires 32 bit support in memory access thus a 68030 cpu, and not a 68000.
Nicolas


Oh wow, that is awesome, I only updated to 1.9 about a hour ago and not seen that option yet :)

EDIT1: the arrows don't seem to change it from N/A :?

You need to use the falcon/winuae version, not the STF one (there're 2 exe in the zip archive)

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Re: Checking for alt-ram ?

Postby exxos » Thu Jan 07, 2016 10:36 pm

npomarede wrote:You need to use the falcon/winuae version, not the STF one (there're 2 exe in the zip archive)


ahhh, the falcon one I stopped using a couple hours ago as stuff never seems to work right in it. My program runs ok on Hatari but not in the falcon one :roll:
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Re: Checking for alt-ram ?

Postby npomarede » Thu Jan 07, 2016 10:42 pm

exxos wrote:
npomarede wrote:You need to use the falcon/winuae version, not the STF one (there're 2 exe in the zip archive)


ahhh, the falcon one I stopped using a couple hours ago as stuff never seems to work right in it. My program runs ok on Hatari but not in the falcon one :roll:

Unless you use some fancy video modes, many falcon programs are known to run, including demos and games (there can be speed problem when dsp is involved).
Alt-RAM requires a falcon (with some hack in TOS 4, automatically done by Hatari) or a TT (with TOS 3). The STF/STE version won't work with alt RAM because it is limited to 24 bit addressing.


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