Izarra 3000 User Manual

The Izarra 3000 is a fixed machine. This manual describes it as built: what you see when you power it on, what the boot menu and setup panel offer, and what each control does. None of the hardware here is user-selectable in the way a real PC's BIOS setup lets you swap parts. IzarraVM reproduces one machine, and this manual reproduces its manual.

Tech specs

Area Izarra 3000 hardware
CPU GSW-586, a Pentium MMX-class part at 200 MHz on a 66 MHz bus. Toka-DOS can throttle it to 486DX2 66 MHz, 386DX 25 MHz, or a slower 286-class mode, without rebooting.
Memory 24 MB SDRAM, with Toka-DOS mapping itself out of conventional memory when DOS games need the first 640 KB.
Graphics VEGA chipset: Margo 2D, Distira 3D, 4 MB video memory, VESA VBE 2.0, VGA mode 13h, and up to 1024x768 at 32-bit color.
Sound ReSonique 2: Sound Blaster 16 compatible digital audio, OPL3 FM, and a Yamaha ADPCM-B DAC.
Storage IDE hard disk, ATAPI CD-ROM with CD audio, and a 1.44 MB floppy drive.
Display 15-inch CRT, up to 1024x768@75Hz.
Firmware 2 MB ROM with the Izarra BIOS, Toka-DOS (FreeDOS-based), and bundled tools.
I/O PS/2 keyboard and mouse, serial, parallel, VGA, line out, line in.

See the company story for where the machine came from, and the DOS command reference for the software side.

Powering on: the POST screen

Turning the machine on runs the Izarra-BIOS power-on self test (POST). Unlike the scrolling text most PC BIOSes print, the Izarra-BIOS draws a graphical screen on the Margo chip's own linear frame buffer: a cream field, a red "Izarra 3000" wordmark, and a row of component icons that light from grey to color as each part passes its check. The header reads:

Izarra-BIOS v3.01 - 1997
Running diagnostics...

Diagnostics run in a fixed order, each pausing briefly so the check is visible rather than flickering past: CPU identity, Margo video, RAM count-up, the Lotura chipset, the 8042 keyboard controller, the PIT timer, the COM1 UART, the Sound Blaster DSP, the OPL FM synth, the floppy controller, the hard disk, and the ATAPI optical drive. A part that fails stays grey (its icon never lights) and the machine carries on to the next check rather than stopping cold.

Two hints sit under the header for the whole POST sequence:

DEL ► Configuration menu
TAB ► Select boot device

Either key can be pressed at any point during POST, not just at the very end; the first one pressed wins. Press neither, and the machine boots normally once diagnostics finish.

The Tab boot menu

Press Tab during POST to open the boot and speed menu. It draws as a single boxed panel over the POST screen, titled "Boot & Speed," with two stacked sections and an Accept row. Move between rows with Up/Down; Enter marks a row or fires Accept; F10 also accepts; Esc cancels back to the saved boot order without changing anything.

Boot device: three rows are Hard Disk, Floppy A:, and CD-ROM. The floppy is always selectable. Hard disk and CD-ROM are only selectable when the boot menu finds media to boot from; an unavailable row is drawn in grey.

CPU speed has four rows, from fastest to slowest:

Row Speed class Port/CMOS code
Fast 586 GSW-586 at full speed 2
Slow 486 486DX2-equivalent 1
VSlow 386 386DX-equivalent 0
SSlow 286 286-equivalent, the slowest tier 3

Accepting the menu writes the chosen speed to the Lotura chipset's mode port immediately (the CPU actually changes speed class right there) and saves both the boot device order and the CPU speed to CMOS as the new defaults for future cold boots. There is no separate reboot: the machine falls straight through to booting the chosen device at the chosen speed.

The same four speed classes are reachable from inside Toka-DOS at any time with the GSWMODE command; see the DOS command reference.

The Del setup panel

Press Del during POST to open the configuration panel, also drawn on the Margo linear frame buffer, titled "IZARRA 3000 SETUP." It edits a working copy of your settings; nothing is written to CMOS until you save. The panel has eight rows, moved between with Up/Down. A one-line help string under the box changes to describe whatever row is highlighted.

Row What it does
Time Opens a sub-page to set the clock: hour, minute, second, day, month, year. Left/Right picks the field, Up/Down (or Enter) changes it, Esc returns.
Keyboard Cycles the active keyboard layout with Left/Right (or Enter). Seventeen layouts are available (US, UK, Spanish, French, German, Italian, and others).
CPU Mode Cycles the boot-time CPU speed with Left/Right (or Enter): 386, 486, 586, then 286, wrapping, the same four classes as the Tab boot menu, in the same order the hardware answers them.
Peripherals Opens a sub-page that re-runs the POST hardware checks live (they are non-destructive) and lists each as PASS or FAIL: Lotura, 8042 KBD, PIT Timer, COM1 UART, SB DSP, OPL FM, and Margo VGA.
Repair Toka-DOS Reinstalls Toka-DOS onto the hard disk from the ROM's built-in image, for when the installed copy is damaged or missing. Reports "Toka-DOS repaired" on success. See Repair Toka-DOS for exactly what this touches.
Save and Exit Commits the working copy (keyboard layout and CPU mode to CMOS, the clock to the real-time clock if you changed it) and reboots.
Discard and Exit Throws away any changes and reboots. Esc on the main menu does the same thing.

What CMOS remembers

Two settings persist across power cycles: the keyboard layout and the CPU mode the machine boots at. Both are written only when you choose Save and Exit; the Tab boot menu's Accept also writes the CPU mode (and the boot device order) directly, without going through the setup panel. A checksum covers the saved settings, so a corrupted CMOS is detected and the BIOS falls back to defaults rather than booting on garbage.

Next