ees@vax135.UUCP (Gene Sampieri) (07/09/84)
TI-99/4A Memory Map >0000 Console Rom; Interupt vectors, XOP vectors GPL Interpreter, Floating POINT routines, XMLINK veectors, >1FFF Low-level cassete DSR etc >2000 Low Memory Expansion Ram; Varies according to the loader used (Assembly). Generally >3FFF not used by XBASIC programs. >4000 DSR ROM; Device service routines. Determined by CRU bit setting >5FFF Disk Controller, RS232 etc. >6000 Cartridge Port (ROM & MINI MEM) 12k of XBASIC ROM. Upper 4k @ >7000 - >7FFF is flipped to page in another 4k for a >7FFF total of 12k. >8000 RAM Mem. Mapped Devices - VDP, GROM, SOUND, SPEECH. >8000 Duplication of scratch pad RAM at >8300 - >83FF >8100 Dup. as above >8200 again >8300 Scratch Pad RAM >8400 Sound Chip >8800 VDP READ DATA >8802 VDP STATUS >8BFF >8C00 VDP WRITE DATA >8C02 VDP READ/WRITE ADDRESS >8FFF >9000 SPEECH READ >93FF >9400 SPEECH WRITE >97FF >9800 GRON/GRAM READ DATA >9802 GROM/GRAM READ ADDRESS >9BFF >9C00 GROM/GRAM WRITE DATA >9C02 GROM/GRAM WRITE ADDRESS >9FFF >A000 HIGH MEMORY EXP RAM XBASIC high memory usage, Free space end pointed to by CPU RAM PAD address >8366 Numeric Values Line Number Table XBASIC Program Space >FFFF for a total of 24k bytes. Additional Memory Space not in the CPU address space; VDP RAM >0000 - >3FFF 16k bytes. This is the console RAM space, and is separate from the rest of the CPU memory. Without memory expansion, XBASIC and BASIC programs reside here. (BASIC does not use expansion memory.) (Assembly language does not use this area.) This covers the memory map for the 994a Later I will put up the full map for the VDP. Note; BASIC does not use memory expansion at all. Only XBASIC, Assembly, FORTH etc. do use it. Chunks of memory are used by various periphals as buffers, thus the amount indicated by CALL SIZE is right. By using CALL FILES(1) followed by NEW, you can get back some, but disables the disk system. If you don't have it instal- led, but have mem exp. you will have more memory to use automatically. (ever look at apple ? out of 48k or 64k you end up with only ~32k or 48k when periphals are enabled) Gene Sampieri ATT-BL (201)949-4707 vax135!ees