joeb@pro-starbase.UUCP (Joe Burke) (06/10/88)
Is there anyway to use the extended memory of the Extended 80-col card with the regular memory? Thanks. Joe (Joeb)
jm7e+@ANDREW.CMU.EDU ("Jeremy G. Mereness") (06/14/88)
>From: Joe Burke <pnet01!pro-starbase!joeb@nosc.mil> >Is there anyway to use the extended memory of the Extended 80-col card with >the regular memory? Thanks. The 65c02 in the Apple //e can only address 64K of memory at a time. in order to use any extended memory, you have to perform what is known as bank-switching where the machine litererally swaps one 64K bank for another. This can be a problem, as just routines must exist in each bank of 64K to take care of itself when you make the switch. It's a mess, and cards like RAMWorks, which are simply extended 80-column cards multiplied over a few times, only make it worse. However, Prodos has routines that can handle extended memory. Appleworks is a brilliant example of how a large program can use Prodos routines to fit itself within the tiny 64K space the 65c02 allows. What is done is the program is segmented and Prodos handles the memory switching. Check out Appleworks running under a 512K Ramworks (eight 64K banks) with AE's enhancements that put all of Appleworks into a RAM, still manages to enlarge the desktop (the Appleworks desktop is handled by Prodos routines (I think) and kept in extended memory) and also provides a print buffer; a feature unique to RAMWorks. No other Ramcard can feature a print buffer. I do not think GSRam or slot 1-7 cards are capable of it. Obviously, I do not know how this feature can work, and Applied Engineering isn't telling. I hope this gives you an idea as to what you can and cannot do with extended memory. If I had my way, I would have a //e with 512K extended to hold a huge desktop/print buffer and then have an additional 512K in a slot 1-7 card to act as a RAM disk. But that takes money and another slot... Capt. Albatross jm7e+@andrew.cmu.edu ============ disclaimer: These opinions are mine and will remain so until more intelligent or insightful or informed people are kind enough to show me the error of my ways. Remember: A mind is a terrible thing to baste.
SEWALL@UCONNVM.BITNET (Murph Sewall) (06/14/88)
>Is there anyway to use the extended memory of the Extended 80-col card with >the regular memory? Thanks. How do you mean that? What's not "regular" about the memory on the extended 80 column card (it's part of the memory of a 128K Apple). It's only "irregular" in that it needs to be bank switched (16K at a time, as the scheme goes) because a 6502 only addresses 64K (16K of which is ROM, so there's 16K of bank switched memory even in a 64K ][+). A LOT of software already uses the extended memory (AppleWorks, for example). ProDOS will allow the extended memory to be formatted as a RAM disk when 64K applications are used (Applesoft, for instance). Beagle Brothers puts out a couple of utilities that use the extended memory (as RAM in DOS 3.3, and "Extra K" allows you to switch between two Applesoft programs - one in main memory, one in the extended memory). If you want to switch the memory banks yourself, Gary Little's INSIDE THE //e (or INSIDE THE //c) is an understandable reference for a beginner (and a reasonable reference for the somewhat more advanced too). --------------------- Disclaimer: The "look and feel" of this message is exclusively MINE! (subject to change without notice; void where prohibited) ARPA: sewall%uconnvm.bitnet@mitvma.mit.edu Murphy A. Sewall BITNET: SEWALL@UCONNVM School of Business Admin. UUCP: ...ihnp4!psuvax1!UCONNVM.BITNET!SEWALL University of Connecticut
kamath@reed.UUCP (Sean Kamath) (06/17/88)
In article <8806111237.AA19491@crash.cts.com> pnet01!pro-sol!pro-starbase!joeb@nosc.mil writes: >Is there anyway to use the extended memory of the Extended 80-col card with >the regular memory? Thanks. > >Joe (Joeb) In what way? data storage, RAMdisk, program memory, display page? I assume by the statement "With the regular memory" to mean as program space. In Basic, you might want to check out Extra-K, which lets you put variables and such into aux memory. If you are into assembly, then take a good long look at auxmove and the other one, xfer, the latter moving control to the other RAM bank. Please be more specific. Sean Kamath -- UUCP: {decvax allegra ucbcad ucbvax hplabs ihnp4}!tektronix!reed!kamath CSNET: reed!kamath@Tektronix.CSNET || BITNET: reed!kamath@PSUVAX1.BITNET ARPA: reed!kamath@PSUVAX1.CS.PSU.EDU US Snail: 3934 SE Boise, Portland, OR 97202-3126 (I hate 4 line .sigs!)