2021-01-02 19:47:57 +00:00
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FLOPPY DISK IDEAS:
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* I am not going to write my own DOS
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* I will use ProDOS - BOOTI-compatible, modern
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* ProDOS 2.4.2 - https://prodos8.com/
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* Generate file(s) to be injected into a blank bootable ProDOS disk image
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thinking:
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neut.tower contains all code / data
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loader.system contains a small program that maps offsets of 512-byte blocks to memory addresses
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- is loaded to 0x2000 & will be wiped by gfx? No, PRODOS is loaded at $2000 and moved
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- no, XXX.SYSTEM is loaded to 0x2000 as well
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- Alternately, we could write one program that batch-loads the whole game into $2000 and moves it to where it belongs?
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- How big is the game with all levels? Could we load the whole thing into consecutive memory starting at $4000?
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- (I don't think this would work on 32kb tape-loaded machines...)
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- With ProDOS I can assume 64kb
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prodos claims:
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$bf00-$ffff - ProDOS
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$9600-$bf00 - BASIC.SYSTEM - don't care?
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$0100-$0800 - "other use or reserved"
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$3A-$3F - used by disk routines, unsafe
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$40-$4F - used by ProDOS but preserved, safe to use
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system bitmap: marks pages of memory as "not valid to allocate a file buffer"
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- loader will have to protect memory that it will be moving game code to?
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https://prodos8.com/docs/techref/calls-to-the-mli/
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the existence of SET_BUF should mean we can load directly to the memory
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we care about? orr I guess 512 bytes is housekeeping stuff (index block)
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16kb version - $0000-$4000 - no we need at least 32kb
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there's basically only 5kb of code space for an hgr game?
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$0000-$03ff 0kb-1kb - zp, stack, input buffer, DOS
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$0400-$07ff 1kb-2kb - text page 1
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$0800-$0bff 2kb-3kb - text page 2
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$0c00-$1fff 3kb-8kb - free space
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$2000-$4000 8kb-16kb - hgr gfx page 1
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2020-12-12 01:53:46 +00:00
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Game:
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* level loading
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2020-12-15 04:14:35 +00:00
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* Title screen
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* Ending screen
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2020-12-12 01:53:46 +00:00
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2020-11-21 18:40:47 +00:00
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tooling ideas:
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* REPLy buffer (Polywell?)
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2020-12-15 04:14:35 +00:00
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* save player positions & map state during hot reload
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* debug movement (noclip? teleport? activate by clicking? MAME supports mouse input / debug overlays...)
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2020-11-21 18:40:47 +00:00
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