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Re: Saturn / Titan Accelerator II
STYNX wrote:
I'm having trouble getting my Accelerator II (not IIe) up to speed :)
It just seems to sit there at normal speed (1Mhz) - thats quite
frustrating. I can remove the mainboard-CPU and the system still boots
- which means the card works. BUT no speedup at all ! There were 2
PROMs in the package. Both seem to work but different in a way. There
is a LED on the card which lights up (PROM No.1) and blinks when the
Floppy is used. Using the 2nd PROM (instead of No.1) the LED doesn't
light up? I have tried the POKE 49286,5 49286,10 command but the speed
doesn't change (I think thats because the 49286-Address may only be
for the Accelerator //e). Im using a Apple //e with 1024K aux-memory.
The memory is recognized contrary to the things i have read on the
Internet regarding the Accelerator II. The tItan.dsk from the asimov-
ftp-archive is garbage and doesn't work. Any Ideas? How can i check
the speed ? No program so far has shown any notable acceleration.
greetings stynx
I would expect the memory to be accessible, and therefore "recognized",
but it may not be cached, and so not accelerated. Unless the card
recognizes the bank switching protocol, it cannot keep the proper
association of bank and address for cached date.
The LEDs are not associated with the EPROMs in any way. They are
reflective of accelerator modes. I'm sure the documentation for this
card is around...
I'd also expect the speed controls (and other controls for the card)
to be in the /DEVSEL space for the slot the card is in. That would
be $C080 + slot*16 + <0..F>, so if the card is in slot 4, the control
addresses would be $C0C0..$C0CF.
I also seem to recall that the card defaults to accelerated mode, unless
the ESC key is pressed right after RESET, but that may be a false
recollection. ;-)
Are there DIP switches to set which slot accesses are fast or slow?
An easy test for acceleration (if the speaker accesses are not slowed
down) is to press ctl-G (bell). The beep will be much higher pitched
and shorter if the machine is accelerated.
-michael
NadaNet 3.1 for Apple II parallel computing!
Home page: http://home.comcast.net/~mjmahon/
"The wastebasket is our most important design
tool--and it's seriously underused."