GVP-BaseBoard Conflicts?
16 messages in this thread
I'm running an Amiga 500 with a 4.5-Meg BaseBoard in my memory expansion
slot. I also have a GVP Series II hard drive with an empty RAM expansion
area.
I'd like to use that area to expand my 500 more, but I'm afraid of
memory conflicts. Some of the BaseBoard memory is mapped into the
AutoConfig space (which I assume the GVP uses) and I'm worried that the
overlapping memory boards will cause errors.
Is anyone aware of this sort of thing being tried before? If so, what
was the outcome? I'm *really* not all that willing to experiment with the
only computer I have, but I also don't want to give up all the memory I
have.
Help?
Len Lekx
[73300,723]
Len,
I'd strongly suggest against trying to mix the GVP ram and the BaseBoard
ram. There WILL be conflicts, and you won't like the results.
In all honesty, any memory expansion for the A500 that plugs into the
trap door that is larger than the standard 512K is not such a good idea.
While the expansion is cheap, it is also subject to the CHIP memory
bandwidth problems that show up when you use 8 or 16 color hires screens.
(ie.. it is not FAST ram, nor is it CHIP ram, it's just SLOW ram) They also
are not designed according to the system interface specs, which causes
problems when you wish to add additional devices. (your GVP memory as an
example)
Dean
DKB Software
Dean-
>There WILL be conflicts, and you won't like the results.
I understood that. (*SIGH*) But I already _have_ the BaseBoard, and
have had it fully occupied for years now. I just got the GVP, and was
wondering about adding memory to it.
Since some of the memory on the BaseBoard isn't in the AutoConfig space,
I think I might just be able to get away with removing some of the chips
from the BaseBoard, and installing RAM in the GVP slots to make up for it.
(Looking at the BB's memory map, I figure I lose about 1/2 meg for every 2
I install. If I limit myself to the cheaper 1-meg SIMMS, I can get
7.5-megs of memory by taking out two rows of BaseBoard chips.)
Thanx for the note.
Len Lekx
[73300,723]
Len,
I'm afraid that won't work either. Due to the way the BaseBoard software
works, you'll end up with several chunks of your GVP memory added into the
system memory lists twice. If you're lucky you'll get an immediate GURU or
lockup. If you're not lucky, you might get far enough into an application
to lose some valuable data.
The trap door RAM expansions are really bad hacks. They work fine in the
system by themselves, but the minute you add something extra to the machine
all bets are off.
Dean
DKB Software
Dean-
Well, if that don't take the cake! (^_^) Pity, it means that I'm
going to have to get $300 worth of SIMMS for the GVP to make up for all the
memory I have on the BaseBoard. (Oh well, at least I won't have to worry
now about that bigger power supply I was thinking of getting.) Ah well,
maybe I'll get lucky and be able to sell the BaseBoard to some other 500
user who doesn't have a hard drive (*_*)
Len Lekx
[73300,723]
Len,
I may have given you the wrong impression. The HD should not have any
problem with the BaseBoard or any other trap door RAM expansion. Memory
expansion is quite risky though.
What kind and how many SIMMs does your GVP require to expand your memory
to what you have on the BaseBoard? $300 seems excessive for 4 megs. (if
that is what you meant)
Dean
DKB Software
Dean-
>The HD should not have any problem with the BaseBoard or any other trap
door
>RAM expansion. Memory expansion is quite risky though.
I took some time to map out the areas of memory the BB places its memory
in. I think I'd be safer just taking the BB out and putting the memory in
the GVP. It might also do wawy with the GURU errors I've been getting
(8000 0003-B – corrupt memory, I think)
If I want to expand to what the BaseBoard has (4 meg) it requires 4 1-Meg
SIMMS. If I want to go further (8 Megs) it takes 2 4-Meg SIMMS. I've been
going to local computer stores comparing prices, and the lowest price I've
gotten is $55 (CDN) for one 1-Meg SIMM – making a 4-meg expansion total
$220. Add a total of 15% taxes, it adds up to $253. (Not $300, but close)
If I want to go to 8 Megs, well, I think they're around $150 each up here.
Len Lekx
[73300,723]
Len,
My math says you should go for the 2 4Meg SIMMS. $150 x 2 + 15% = $345
for 8Megs. Or $92 for the additional 4Megs.
Dean
DKB Software
Dean-
The $150 price for 4Meg SIMMS might be the American price. After all,
you can get 1Meg SIMMS for less than $40 down there. (^_^) So you can
figure that a 4Meg SIMM up here would cost somewhere around $180. So…
180 x 2 + 15% = $414. Not the kind of dough I have on hand at the moment.
(^_-)
Len Lekx
[73300,723]
That's a pretty general condemnation of A501 slot memory expansion devices.
I assume you've tested them all?
Craig
Craig,
I've looked at quite a number of them, and they all work in a very
similar manner. If anything I said was incorrect or misleading, please
point it out to me. I'd be more than willing to listen to any corrections
you might have.
Dean
DKB Software
What you said was "The trap door RAM expansions are really bad hacks." How
do you define a "really bad hack"?
"They work fine in the system by themselves, but the minute you add
something else to the machine all bets are off." Do you have examples for
all trap door RAM expansions to support this statement? The statement
implies that none of them work with any additional hardware and is a very
general condemnation (but not as general as "really bad hack").
Craig
Craig,
Really bad hack is my opinion, one that I'll stand by. The trap door RAM
expansion products hard code themselves into the autoconfig memory space
_without_ autoconfiguring. This means that the system has no way of knowing
where to put any additional devices if they are added on. (…all bets are
off…) Chances are that there _will_ be a conflict under such
circumstances.
A hack by my definition is a product that does not install in a system
defined manner. I sell products that fit that description when there is no
other way to provide the functionality. A bad hack is one that ignores
system conventions when a supportable method exists.
Dean
DKB Software
Still no details? Still no specific examples? That's what I asked for.
Craig
Craig,
What do you want? Product names, Company names? an RWAR?… Sorry,
that's not why I'm here. Somebody asked a question and I answered it, I'm
sorry you didn't like the answer. Relating to the specific product in
question the answer is perfectly correct. It WON'T work.
Dean
DKB Software