Toshiba · T-series
Toshiba T5100
A landmark 16 MHz 386 portable with EGA-compatible graphics and a four-level plasma display.
EXPERIMENTAL alpha candidate: earlier tests booted Toshiba DOS 3.30 from the internal IDE disk and TESTCE3 4.30 from floppy; regression with this build is pending. The original AGS video ROM is missing: BluMach adapts a separately supplied IBM EGA ROM only in memory. Functional compatibility, not faithful AGS/CELT recovery. Full diagnostics, upper EMS and floppy writes remain unvalidated.
History
Announced in the United States in September 1987, the T5100 put a desktop-class 16 MHz 80386DX, hard disk and gas-plasma screen into a transportable case. Contemporary reviewers valued its smaller size, standard EGA compatibility, display proportions and keyboard, even while the 20 MHz Compaq Portable 386 was faster. Toshiba offered 40 MB and 100 MB storage variants; the Japanese J-3100SGT family must not be treated as firmware-identical.
Hardware
- Processor
- Intel 80386DX, 16/8 MHz; optional Intel 80387
- Memory
- 2 MB standard; optional 2 MB memory card
- Video
- Toshiba AGS/CELT EGA-compatible graphics and 640 × 400 four-level gas-plasma panel
- Floppy drive
- One internal 3.5-inch 1.44 MB drive; 720 KB media supported
- Interfaces
- Integrated IDE, serial, parallel, external RGB display and Toshiba keyboard controls
Catalogue classification
- Form factor
- Transportable
- Mobility
- Portable
- Processor generation
- 80386 class
- Graphics standard
- EGA
- Display technology
- Plasma
- Display colour
- Amber
- Storage interface
- Floppy drive, IDE
Research
This page separates documented hardware facts, behavior observed in original firmware, and the current fidelity of BluMach emulation.
Sales and commercial configurations
Evidence: documented or confirmed hardware
- Markets and period
A high-end transportable business computer, announced in the United States at USD 6,499 and positioned as a desktop-class 80386 system that could travel.
- Commercial models
The international baseline used a 16 MHz 80386DX, 2 MB RAM, a 1.44 MB floppy drive and either a 40 MB or 100 MB hard disk. Toshiba documents CP-342/type 6, CP-3044/type 7 and CP30104/type 9 drives. Regional J-3100SGT variants are distinct targets.
Architecture and memory
Evidence: documented or confirmed hardware
- Memory
2 MB standard with a documented optional 2 MB card. The tested profile provides 640 KB conventional, 1 MB extended and 384 KB LIM memory; 24 bank-0 LIM pages pass a bounded guest probe. The upper EMS allocation and exact gate-array mapping are not modeled.
- Video
The hardware uses Toshiba AGS/CELT logic for EGA/CGA/MDA compatibility and a four-level 640 × 400 gas-plasma panel. The experimental model wraps standard EGA behavior, 256 KB VRAM and 2 KB SRAM with an orange four-level palette. Right Ctrl acts as Fn: Fn+End and Fn+Home select external RGB or internal plasma through the BIOS-observed 8066h/BCh handshake, while Fn+Down toggles an approximate 350/400-line host presentation. Guest timing remains 640 × 350.
- Storage
One internal 1.44 MB floppy drive and an integrated IDE-compatible disk interface. The tested CP-3044 profile uses 980 cylinders, 5 heads and 17 sectors with BIOS type 7. DOS 3.30 FDISK, FORMAT /S, persistent file readback and a cold hard-disk boot pass.
BIOS and firmware
- Known revisions
Toshiba system BIOS V2.30 uses 32 KB EVEN 042F and ODD 043F lanes. The missing original 32 KB AGS ROM is represented only by an identified IBM EGA ROM adapted in memory with six BIOS-observed conservative handoff returns. No firmware is distributed.
Emulation status
Evidence: current BluMach status; not necessarily a description of the original circuit
- Screen controls
The manual documents contrast and brightness for the four-level neon-orange plasma. View → Screen controls offers both on the internal display, with Restore defaults. External RGB is unchanged. Plasma is emissive: no LCD backlight switch. Optical curves are approximate, not calibrated.
- Verified
With 2 MB RAM, internal display, 1.44 MB floppy and the 980/5/17 type-7 disk, Setup is legible, POST reaches 32, Toshiba DOS 3.30 boots from hard disk and read-only TESTCE3 4.30 reaches its main menu. A sampled 1 MB extended-memory test and the 24-page LIM subset also pass.
- Pending or approximate
Original AGS/CELT firmware, exact 640 × 400 scan conversion, gray transfer, physical output gating, Fn+Right font switching, upper EMS, full diagnostics, floppy writes, warm reset/resume and exact Conner timing remain pending. The current result is compatibility-oriented and not cycle accurate; a live BIOS hotkey round trip still needs interactive validation.
Engineering
This public engineering narrative explains how the evidence became an emulator implementation, including failures, compromises, validation and replacement criteria.
Sources
Preserved research material
Evidence: primary sources and research notes