More on BAD CHIP RAM
26-Nov-90 11:51:51
Sb: #7102-More on BAD CHIP RAM
Fm: Gregory B. Tibbs 73767,456
To: Don Curtis/SYSOP 76703,4321
Just remember that memory at C00000H is found because the OS is set up that
way. You can have any type of read/writable memory decoded at any speed
(virtual paper tape?) and the OS will use it.
My Rejuvenator design moves all three custom chips onto their own bus,
separate from the old motherboard chip ram bus. When two jumpers are set
properly, the motherboard 512K is decoded at C00000H and it is found
automagically. Pull the jumpers, due to a memory conflict (say with the
aforementioned Insider), and you have to addmem it back in at whatever
address the user set the jumpers to.
I have run tests with Dpaint and a memory speed test (RAMSPEED from Fish
31) and have proven that a 16 color hires screen causes the ram benchmark
to slow only a very small amount versus just using chip ram alone. The
speed difference was on the order of 28.5 s seconds with the fast ram, 72
seconds with the 16 color hires screen (DPaint doing nothing).
-Greg