libretro/emulators/sdl2trs.yml

emulator: SDL2TRS
type: standalone
core_classification: community_fork
source: "https://gitlab.com/jengun/sdltrs"
upstream: "http://sdltrs.sourceforge.net"
profiled_date: "2026-08-08"
source_commit: "a9b30ff3cfe2b44ccff094fcd5d3c5b60e78b8a2"
core_version: "1.2.35"
display_name: "Tandy - TRS-80 (SDL2TRS)"
cores:
  - sdl2trs
  - sdltrs
systems:
  - trs80
mode: standalone

notes: |
  TRS-80 Model I, III, 4 and 4P emulator. Jens Guenther's GitLab tree continues
  Mark Grebe's SDLTRS, itself an SDL port of Tim Mann's xtrs, whose licence
  still ships as xtrs.LICENSE. The sdl2 branch builds the sdl2trs binary that
  ES-DE and RetroDECK look for; master builds sdltrs for hosts without SDL2
  (README.md:106-111). The branches diverge only in the display and paste code:
  trs_cmd_rom.c and trs_memory.c are byte-identical between them.

  Three ROM slots exist, one per model family, and trs_rom_init picks one from
  trs_model. Model I takes romfile1, Model III and Model 4 share romfile3, and
  Model 4P takes romfile4p (trs_cmd_rom.c:868-894). The defaults are level2.rom,
  model3.rom and model4p.rom, each prefixed by ROM_PATH (trs_options.c:900-902).
  ROM_PATH is a build define left empty unless a packager sets it
  (trs_options.c:53-54, CMakeLists.txt:42), so a stock build resolves the names
  against the working directory.

  -rom, -r and -romfile write to the slot of the model selected at the moment
  they are parsed (trs_options.c:611-622). Options are applied in command-line
  order after the config file has been read (trs_options.c:1020-1040), so -m has
  to come first to redirect them, and a model key in the config file otherwise
  decides. -rom1, -rom3 and -rom4p address a slot directly. The GUI ROM browser
  filters on .bin, .hex, .iii and .rom (trs_sdl_gui.h:63, trs_sdl_gui.c:2591-2597).

  trs_load_rom sniffs the first byte. A colon means Intel hex, and load_hex
  rejects the file on a line checksum mismatch. A 1 or a 5 on Model III or later
  means a MODELA/III CMD file, rejected above 14 KB. Anything else is read as
  raw binary with no check (trs_cmd_rom.c:720-767, 779-843), which is the path a
  dump takes. No hash is computed anywhere in the tree. rom_write drops any byte
  at or past MAX_ROM_SIZE, 18432 (trs_memory.c:63, 742-745), and trs_rom_size,
  the extent of the plain ROM mapping, is capped at 14336 (trs_cmd_rom.c:896-898).

  A failed load is not fatal. Model I and Model III/4 fall back to trs_fakerom,
  which prints "You do not have a ROM image installed for Model" and spins.
  Model 4P falls back to trs_rom4p, Pete Cervasio's free boot ROM, which boots
  Model 4 operating systems from floppy (trs_cmd_rom.c:871-893). -stringy
  overlays the built-in Exatron Stringy Floppy ROM at 0x3000 over the Model I
  image (trs_cmd_rom.c:875-876), and -hdboot rewrites the loaded Model I ROM in
  place to boot from a hard drive (trs_cmd_rom.c:447-610, 882-883).

  The clones run off the same three slots and are recognised from the ROM data
  rather than from an option (trs_clones.c:8-20, html/Features.html), so their
  larger images load as a Model I or a Model III ROM. None has a filename of its
  own anywhere in the tree.

files:
  - name: level2.rom
    description: "TRS-80 Model I ROM"
    required: true
    max_size: 18432
    source_ref: "src/trs_options.c:81 (romfile1), src/trs_options.c:900 (default name), src/trs_cmd_rom.c:871-884 (trs_model 1)"
    note: >
      Model I is the model a stock configuration selects (trs_options.c:927), so
      this is the slot an unconfigured run reads. Without it the machine runs the
      compiled-in diagnostic stub and nothing else. max_size is the shared ROM
      buffer ceiling: a longer file is truncated, never rejected, and only the
      first 14336 bytes reach the plain memory map.

  - name: model3.rom
    description: "TRS-80 Model III and Model 4 ROM"
    required: true
    max_size: 18432
    source_ref: "src/trs_options.c:82 (romfile3), src/trs_options.c:901 (default name), src/trs_cmd_rom.c:885-889 (trs_model 3 and 4)"
    note: >
      Serves Model III and Model 4 alike; the stub text spells out that Model 4
      mode needs a Model 3 image (trs_cmd_rom.c:110-115). This is the one slot
      that also accepts a MODELA/III CMD file, which html/index.html presents as
      the substitute for a real Model III ROM. Same truncating ceiling as the
      Model I slot.

  - name: model4p.rom
    description: "TRS-80 Model 4P boot ROM"
    required: false
    max_size: 18432
    source_ref: "src/trs_options.c:83 (romfile4p), src/trs_options.c:902 (default name), src/trs_cmd_rom.c:890-893 (trs_model 5)"
    note: >
      Optional because the compiled-in replacement is a working boot ROM rather
      than a stub. html/index.html states the free ROM boots only Model 4
      operating systems, not Model III, and only from floppy, so the original
      image is what restores Model III mode and hard-drive booting. Hard drive
      unit 0 is tried before floppy by the Radio Shack ROM, and F2 held at boot
      forces floppy (html/Features.html).

analysis:
  embedded_roms:
    mechanism: "Uint8 arrays in trs_cmd_rom.c, copied into the ROM buffer by trs_load_compiled_rom (trs_cmd_rom.c:769-777)"
    extraction: "hashes computed from the decoded byte literals"

    entries:
      - symbol: trs_fakerom
        role: "Fallback for Model I and Model III/4 when the slot cannot be read"
        source_ref: "src/trs_cmd_rom.c:56-116, src/trs_cmd_rom.c:873,888"
        load_address: 0
        size: 461
        crc32: 5f85edf9
        md5: de9617738e7ee6633d305777e0ce6a15
        sha1: 42736ddff1944fcd4631168d35f773fc824eeb9b
        note: >
          Writes "You do not have a ROM image installed for Model" plus the model
          digit to the screen and halts on a JR -2. It runs no TRS-80 software,
          which is why both slots it covers are required.

      - symbol: trs_rom4p
        role: "Fallback for Model 4P"
        source_ref: "src/trs_cmd_rom.c:126-193, src/trs_cmd_rom.c:892"
        load_address: 0
        size: 518
        crc32: 57ec35ee
        md5: c8551e6aa36c4bea256d3073c7255ed5
        sha1: 60d4ff043525256fa3072e59ba283a3cb98399f4
        note: >
          Pete Cervasio's free Model 4P boot ROM version 0.06, carried under a
          copy-and-modify notice in the header. Reads and runs a boot sector and
          reports CRC errors, a missing boot sector and an empty drive.
          utilities/xtrsrom4p.z80 is its source and xtrsrom4p.README its manual.

      - symbol: trs_romesf
        role: "Exatron Stringy Floppy firmware, overlaid on the Model I image"
        source_ref: "src/trs_cmd_rom.c:199-441, src/trs_cmd_rom.c:875-876"
        load_address: 12288
        size: 1920
        crc32: 99e3fdc6
        md5: 235d1eb412cfc5696aad8a0a2dc6c53a
        sha1: b2612037600031b5290bace247951e1f99700b36
        note: >
          Loaded over 0x3000-0x377F whenever -stringy is set, on top of whatever
          the Model I slot supplied, and leaves trs_rom_size at 0x3780. Taken
          from the ESF Advanced Programmer's Guide and held to be public domain
          by the header. utilities/esfrom.z80 is its source.

  extended_rom_images:
    note: >
      The clones and the Holmes video card need images larger than a stock ROM,
      and the memory mapper reads the extra regions straight out of the same
      buffer. They arrive through romfile1 or romfile3 like any other image and
      are recognised from the ROM data, so the emulator defines no filename for
      them and no option selects them.
    source_ref: "src/trs_clones.c:8-20 (clone table), src/trs_memory.c:63 (MAX_ROM_SIZE)"
    layouts:
      - machine: "Prologica CP-300, CP-500 and CP-500 M80"
        slot: model3.rom
        image_size: 16384
        source_ref: "src/trs_cp500.c:1-22, src/trs_cp500.c:153-160, src/trs_memory.c:1052-1054"
        note: >
          14 KB of patched Model III ROM plus a 2 KB resident monitor read back
          from 0x3800-0x3FFF and banked into 0x3000-0x37FF. README.md:21 and
          html/Features.html name CP-300 and CP-500 for this 16 KB image.

      - machine: "Holmes VID-80 (VX-3) on Model III"
        slot: model3.rom
        image_size: 18432
        source_ref: "src/trs_memory.c:577-586, src/trs_memory.c:1057-1080"
        note: "4 KB VID-80 ROM with the Model III ROM appended behind it; this pairing is what sets MAX_ROM_SIZE."

      - machine: "TCS SpeedMaster, also sold as Genie IIs"
        slot: level2.rom
        image_size: 16384
        source_ref: "src/trs_memory.c:1025-1048"
        note: "BASIC at 0x0000-0x2FFF and a ROM card read from 0x1000-0x3FFF into 0x4000-0xBFFF. Needs -speedup tcs (html/Features.html)."

      - machine: "Aster CT-80"
        slot: level2.rom
        image_size: 14336
        source_ref: "src/trs_memory.c:962-994"
        note: "BASIC at 0x0000-0x2FFF plus a 2 KB boot ROM at 0x3000-0x37FF, mirrored into 0xEC00 in CP/M mode."

      - machine: "EACA EG 3200 Genie III"
        slot: level2.rom
        image_size: 14336
        source_ref: "src/trs_memory.c:909-931"
        note: "Bank 1 is read through trs_rom_size, so the 14 KB cap on the plain mapping is the ceiling."

      - machine: "TCS Genie IIIs"
        slot: level2.rom
        image_size: 12288
        source_ref: "src/trs_memory.c:932-961"
        note: "Reads 0x0000-0x2FFF only; the rest of the address space is banked RAM, video and the HRG window."

      - machine: "LNW Research LNW80/II"
        slot: level2.rom
        image_size: 12288
        source_ref: "src/trs_memory.c:995-1024"
        note: "Reads 0x0000-0x2FFF only. -speedup lnw sets the 4 MHz clock and the low 16 KB banking."

  character_generators:
    source_ref: "src/trs_chars.c:12 (trs_char_data), src/trs_options.c:404-436 (charset names), src/trs_sdl_interface.c:585"
    note: >
      Every character set is a compiled-in bitmap table selected by -charset1,
      -charset3 and -charset4. The tree holds no external font file and reads
      none. The sets cover the Model I generators, the Model III and Model 4
      Katakana and international sets, and the Video Genie, System 80, HT-1080Z,
      Meritum and Aster CT-80 clones.

  frontend_conventions:
    note: >
      Two frontends fix names and paths the emulator itself does not know. Both
      belong to the platform layer.
    entries:
      - frontend: ES-DE
        source_ref: "resources/systems/linux/es_systems.xml:2211-2213, USERGUIDE.md:3334-3362"
        note: >
          Passes -rom %ROMPATH%/trs-80/level2.rom on all three launch commands
          and -disk0 %ROMPATH%/trs-80/boot.dsk on the DOS Diskette one, with
          boot.dsk documented as a copy of a TRS-80 DOS, NewDos/80 v2.0
          recommended. No command passes -m, so the slot -rom writes to follows
          the config file, which is Model I unless the user changed it, and
          model3.rom and model4p.rom are never named. USERGUIDE.md:3338 records
          that both filenames are case sensitive.
      - frontend: RetroDECK
        source_ref: "RetroDECK/components archive_later/sdl2trs/component_manifest.json"
        note: >
          Declares level1.rom, level2.rom, level3.rom, level4.rom, level4p.rom
          and boot.dsk under $roms_path/trs-80. Of those the emulator opens only
          level2.rom by default; level3.rom, level4.rom and level4p.rom are
          renames of the model3.rom and model4p.rom slots, and level1.rom is a
          Level I BASIC image for the Model I slot. The manifest hashes come
          from the frontend, not from the emulator, which computes none.

  shipped_content:
    source_ref: "CMakeLists.txt:50, CMakeLists.txt:145-146"
    files:
      - diskimages/utility.dsk
      - diskimages/cpmutil.dsk
    note: >
      Installed into the shared data directory by the emulator's own packaging
      and carrying the IMPORT, EXPORT, SETTIME, XTRSHARD, XTRSMOUS and CP/M
      helper programs whose sources sit in utilities/. No code path names them:
      they reach the machine only when a user mounts them with -disk.

  user_supplied_paths:
    note: "Named on the command line, in the config file or in a disk set, with no fixed filename"
    entries:
      - what: "floppy images in drives 0-7, JV1, JV3 and DMK"
        source_ref: "src/trs_options.c:589-594, src/trs_disk.c:789-921"
      - what: "hard drive images, units 0-3"
        source_ref: "src/trs_options.c:595-600, src/trs_hard.c:212-220, src/trs_hard.c:528-609"
      - what: "cassette images, .cas, .cpt and .wav"
        source_ref: "src/trs_options.c:583-588, src/trs_cassette.c:526-553"
      - what: "stringy floppy wafers in drives 0-7, .esf"
        source_ref: "src/trs_options.c:601-606, src/trs_stringy.c:278-316, src/trs_stringy.c:342-346"
      - what: "disk set, a plain list of the paths above"
        source_ref: "src/trs_options.c:607-610, src/trs_disk.c:3765-3802"
      - what: "CMD program loaded straight into memory, from a bare argument"
        source_ref: "src/trs_options.c:1014-1015, src/trs_cmd_rom.c:845-866"
      - what: "serial port tty, defaulting to /dev/ttyS0 on Linux"
        source_ref: "src/trs_uart.c:54-56, src/trs_uart.c:144-202"

  generated_files:
    written_and_read_back:
      - filename: ".sdltrs.t8c"
        source_ref: "src/trs_options.c:939-955, src/trs_options.c:1049"
        note: "Configuration, written to the home directory on first run when none is found."
      - filename: "<name>.t8s"
        source_ref: "src/trs_state_save.c:38-66, src/trs_state_save.c:68-113"
        note: "Emulator state, written and read by the GUI or a bare command-line argument."
      - filename: "blank disk, wafer and hard drive images"
        source_ref: "src/trs_mkdisk.c:192-308, src/trs_stringy.c:187-197"
    written_only:
      - filename: "trsprn####.txt"
        source_ref: "src/trs_printer.c:60-81"
        note: "Printer output, numbered up to 9999 in the printer directory."
      - filename: "screenshots as BMP"
        source_ref: "src/trs_sdl_gui.c:2673"
    note: "Produced by the emulator, none is user-supplied"