(???) on Bettencourt <jonINTERNETrelayCHAT@napaVALLEYnet.CLARInet> wrote:
 (???)  In article <20000212141803.27224.00002819@ng-fv1.aol.com>,
 (???)  supertimer@aol.com (Supertimer) wrote:
 (???)  
 (???)  > What about IIGS memory?
 (???)  
 (???)  You mean 24-bit addressed memory? I don't have any information on that. If
 (???)  you can find any info on it or point me out to where I can find the info,
 (???)  please do.
 (TN3) here isn't much that you can do in a IIgs, outside of the base two
 (???) anks, without using the memory manager toolset.  Here is an overview of
 (???) he whole shebang:
 (???) 000000 - $00BFFF    RAM, equivalent to IIe main memory $0000 - $BFFF
 (???) 00C000 - $00CFFF    I/O, equivalent to IIe $C000 - $CFFF
 (???) 00D000 - $00FFFF    ROM or bank-switched memory, equiv. to IIe main
 (???)                     memory in the same area
 (???) 010000 - $01BFFF    RAM, equivalent to IIe aux memory $0000 - $BFFF
 (???) 01C000 - $01CFFF    I/O, equivalent to IIe $C000 - $CFFF
 (???) 01D000 - $01FFFF    ROM or bank-switched memory, equiv. to IIe aux
 (???)                     memory in the same area
 (???) 020000 - $7FFFFF    RAM (amount varies depending on motherboard and
 (???)                     memory expansion card)
 (???) 800000 - $DFFFFF    Reserved (not implemented in hardware)
 (???) E00000 - $E003FF    RAM, reserved for system use
 (???) E00400 - $E007FF    Text screen 1 (main memory)
 (???) E00800 - $E00BFF    Text screen 2 (main memory)
 (???) E00C00 - $E01FFF    RAM, reserved for system use
 (???) E02000 - $E03FFF    Hi-res screen 1 (main memory)
 (???) E04000 - $E05FFF    Hi-res screen 2 (main memory)
 (???) E06000 - $E0BFFF    RAM, reserved for system use
 (???) E0C000 - $E0CFFF    I/O, equivalent to IIe $C000 - $CFFF
 (???) E0D000 - $E0FFFF    RAM, same layout as IIe bank-switched memory,
 (???)                     reserved for system use
 (???) E10000 - $E103FF    RAM, reserved for system use
 (???) E10400 - $E107FF    Text screen 1 (aux memory)
 (???) E10800 - $E10BFF    Text screen 2 (aux memory)
 (???) E10C00 - $E11FFF    RAM, reserved for system use
 (???) E12000 - $E13FFF    Hi-res screen 1 (aux memory)
 (???) E14000 - $E15FFF    Hi-res screen 2 (aux memory)
 (???) E12000 - $E19FFF    Super hi-res screen
 (???) E1A000 - $E1BFFF    RAM, reserved for system use
 (???) E1C000 - $E1CFFF    I/O, equivalent to IIe $C000 - $CFFF
 (???) E1D000 - $E1FFFF    RAM, same layout as IIe bank-switched memory,
 (???)                     reserved for system use
 (???) E20000 - $EFFFFF    Reserved (not implemented in hardware)
 (???) F00000 - $F7FFFF    Available for ROM disk in memory expansion slot
 (???) F80000 - $FBFFFF    Reserved for future ROM expansion
 (???) FC0000 - $FDFFFF    ROM (in the 1MB/ROM 3 IIgs) or reserved for ROM
 (???) FE0000 - $FFFFFF    ROM
 (IMG) n the 256KB/ROM 1 IIgs, memory banks $02 through $7F are provided by
 (???) AM in the memory expansion slot.
 (IMG) n the 1MB/ROM 3 IIgs, memory banks $02 through $0F are motherboard RAM,
 (???) nd banks $10 through $7F are provided by RAM in the memory expansion
 (SND) lot.
 (???) o application may use any RAM in these banks without first allocating
 (???) emory through the Memory Manager toolset.  In general, applications
 (SND) hould not assume that they can reserve a specific area, and should be
 (???) ble to handle an arbitrary memory area being provided.  There are
 (???) ptions which allow some restrictions, e.g. "don't cross a bank
 (???) oundary" (required for code).
 (TN3) he areas of banks $E0 and $E1 which I've described as "RAM, reserved
 (???) or system use" are acutally a mixture of reserved and available RAM,
 (???) ut none of it should be used except through the Memory Manager.
 (TN3) he Memory Manager must also be used for memory in banks 0 and 1 when
 (???) unning under a native operating system (GS/OS).  If you run a ProDOS-8
 (???) pplication under GS/OS, the entire bank 0 and 1 area is reserved by the
 (SND) ystemm, so applications can't allocate memory in these areas (they
 (???) ormally have full control over the appropriate areas).  If you boot
 (DOC) irectly into ProDOS-8, a IIgs-aware application may need to mimic this
 (???) rrangement.
 (TN3) he specific details of the $C000-$C0FF area are rather a lot more
 (DOC) etailed than the IIe, and I don't want to type all of that in.  (Nearly
 (???) very location is used for something.)  Most of the IIe I/O locations
 (???) re supported on the IIgs.  The main exceptions are missing features:
 (???) TROBE, TAPE IN and TAPE OUT.
 (???) - 
 (???) avid Empson
 (DOC) empson@actrix.gen.nz
 (???) nail mail: P O Box 27-103, Wellington, New Zealand