44cc9f3f6d
Custom TTL design by Marvin Minsky. There are two displays: one raster scan for bitmapped characters, and another random scan for vector graphics. There is also a keyboard, and a UART for talking to a host computer. The computer is normally booted off a ROM which reads and starts a secondary loader from the UART. The loader is responsible for reading the payload, which comes in checksummed blocks. The LOAD command accepts files in same format.
99 lines
4.6 KiB
C
99 lines
4.6 KiB
C
/* tt2500_cpu.c: TT2500 bootstrap ROM contents.
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Copyright (c) 2020, Lars Brinkhoff
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Permission is hereby granted, free of charge, to any person obtaining a
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copy of this software and associated documentation files (the "Software"),
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to deal in the Software without restriction, including without limitation
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the rights to use, copy, modify, merge, publish, distribute, sublicense,
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and/or sell copies of the Software, and to permit persons to whom the
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Software is furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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LARS BRINKHOFF BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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Except as contained in this notice, the name of Lars Brinkhoff shall not be
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used in advertising or otherwise to promote the sale, use or other dealings
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in this Software without prior written authorization from Lars Brinkhoff.
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*/
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#include "tt2500_defs.h"
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uint16 tt2500_rom[] =
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{
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/* BEGIN 0 */ 0010000, /* (NOP) */
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/* 1 */ 0010000, /* (NOP) */
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/* 2 */ 0010000, /* (NOP) */
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/* START 3 */ 0040025, /* (PUSHJ GETC & GET CHAR) */
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/* 4 */ 0007001, /* (SUBI 0 WD & IS WORD "LOGO") */
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/* 5 */ 0147577, /* (147577) */
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/* 6 */ 0133774, /* (BNE START) */
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/* 7 */ 0040022, /* (PUSHJ GETW) */
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/* 10 */ 0074201, /* (GET ADR WD) */
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/* 11 */ 0040022, /* (PUSHJ GETW) */
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/* 12 */ 0074301, /* (GET CNT WD) */
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/* LOOP 13 */ 0040022, /* (PUSHJ GETW) */
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/* 14 */ 0004220, /* (DEC ADR) */
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/* 15 */ 0025100, /* (CWRITE WD) */
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/* 16 */ 0004320, /* (DEC CNT) */
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/* 17 */ 0133773, /* (BNE LOOP) */
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/* 20 */ 0074023, /* (GET 0 XR) */
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/* 21 */ 0050100, /* (JUMP 100) */
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/* GETW 22 */ 0040025, /* (PUSHJ GETC) */
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/* 23 */ 0040025, /* (PUSHJ GETC) */
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/* 24 */ 0040025, /* (PUSHJ GETC) */
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/* GETC 25 */ 0073320, /* (DIS INTS 2) */
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/* 26 */ 0050025, /* (JUMP GETC) */
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/* 27 */ 0010000, /* (NOP) */
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/* 30 */ 0074424, /* (GET CH UART) */
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/* 31 */ 0001444, /* (ANDI CH CH) */
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/* 32 */ 0000017, /* (17) */
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/* 33 */ 0004114, /* (ROT WD 14) */
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/* 34 */ 0001141, /* (ANDI WD WD) */
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/* 35 */ 0177760, /* (177760) */
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/* 36 */ 0002104, /* (IOR WD CH) */
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/* 37 */ 0076016 /* (POPJ) */
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#if 0
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0010000, /* NOP */
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0010000, /* NOP */
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0010000, /* NOP */
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0040025, /* PUSHJ GETC Call subroutine to read TTY character. */
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0007001, /* SUBI 0 WD 32-bit instruction computes 147577 - WD */
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0147577, /* 147577 (The constant "LOGO" is stored here.) */
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0133774, /* BNE START Branch to START if result Not zero. */
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0040022, /* PUSHJ GETW Reads 4 characters to make 16-bit word. */
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0074201, /* GET ADR WD Move word from WD to ADR (register 2). */
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0040022, /* PUSHJ GETW Get next data word into WD. */
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0074301, /* GET CNT WD Move it to CNT. */
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0040022, /* PUSHJ GETW Get another data word. */
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0004220, /* DEC ADR Decrement the Address and use it to */
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0025100, /* CWRITE WD write [WD] into control memory. */
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0004320, /* DEC CNT Decrement the word in CNT (count). */
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0133773, /* BNE LOOP Branch to LOOP unless CNT is zero. */
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0074023, /* GET 0 XR Makes PC leave Bootstrap Loader. */
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0050100, /* JUMP 100 Jump to location 100. */
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0040025, /* PUSHJ GETC Get 4 bits and shift into WD. */
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0040025, /* PUSHJ GETC Get 4 more. */
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0040025, /* PUSHJ GETC Get 4 more. */
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0073320, /* DIS INTS 2 Skip 2 steps if TTY interrupt active. */
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0050025, /* JUMP GETC If not, go back and wait. */
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0010000, /* NOP (Skip over this.) */
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0074424, /* GET CH UART Put the character into CH. */
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0001444, /* ANDI CH CH Mask out all but last four bits by */
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0000017, /* 17 ANDing with 0 000 000 000 001 111. */
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0004114, /* ROT WD 14 Rotate WD four places right. */
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0001141, /* ANDI WD WD Zero out last four bits by */
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0177760, /* 177760 ANDing with 1 111 111 111 110 000. */
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0002104, /* IOR WD CH Finally, OR them together. */
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0075600, /* POPJ Return to calling program. */
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#endif
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};
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