32 vs 16 bit ram
3 messages in this thread
Okay, here's the question:
I think I understand the diffeerence between the two now. (Bottom line,
faster access), but I don't understand how to add 32 bit ram.
I have an A500 with 1meg of chip ram and two megs of fast ram (simms in
my GVP Sries II 40 HD).Say I'd like to add two more megs of ram. I'd know
how to install some more simms in my GVP HD, but how do I add 32 bit
capabilituy so I could add the memory in 32 bit ram?
Then, and here's a really stupid question 'cause I don't think I'll
understand the answer, how doees the computor know where to go for
additional memory. I mean how do I know it won't access the 16 bit ram
instead of the 32. Thanks.
Dan Cole
Dan,
I'm not an expert on this topic so hopefully someone else will also answer
your questions.
I believe you can only add 32-bit Ram if you have an accellerator board
installed in the Amiga. I just sold an A2620 accellerator with 2-megs of
32-bit ram and upgraded to a GVP Combo Board (includes 68030 accellerator)
with 8-megs of 32-bit ram. Once you get an accellerator, there are usually
jumpers on the board that you set, so your system will know to access all
32-bit Ram before it accesses any 16-bit Ram.
So, I guess the bottom line is you have to buy an accellerator card. I
just sold the A2620 with 2-megs of 32-bit Ram the other day for $350. The
68030 boards are still being made, but are much more expensive, but they
are also available used. The new 68040 boards are very expensive.
I hope this helps.
Dom Fontana
Dan,
A GVP Series II is (according to their ad) simply a RAM
expansion/Hard Drive host adapter + drive add-on for your A500. It's not
an accellerator card, thus you're still using your 68000 as the CPU.
Thus, the RAM expansion is more than likely not 32 bit wide…since
it would do you no good. The 68000 can only access data 16 bits at a time.
As to where does the CPU go for additional memory? Fairly simple,
the operating system keeps a list of what memory is available and where
it's addressed, and thus when a program needs more memory…it simply
"assigns" a block of memory from it's free list. The CPU itself hasn't the
faintest idea of what memory exists…doesn't exist. The CPU will
"blindly" follow (or attempt to follow) any instruction given to it. The
operating system (AmigaDOS…specifically the 'exec' portion) is what
allocates memory to a program…and the program itself is what is supposed
to take care it only attempts to access memory that is allocated to itself.
Don