Olivetti · M
Olivetti M28
8 MHz 80286 system with FE2000 logic, Olivetti OGC video and a documented 20 MB commercial configuration.
PARTIAL EMULATION: POST, RTC, CMOS, floppy boot and 1 MB on-board memory are recorded as passing. The commercial 512 KB/20 MB profile uses the GO714, emulated with the WD1003 without its jumpers, and ST-225 geometry as an approximation; the actual Olivetti drive remains to be confirmed. ME903 expansion, warm reset and two interactive diagnostics are pending.
History
The 1986 M28 combined an 80286 at 8 MHz with Olivetti's FE2000 logic, 512 KB of standard memory, a 1.2 MB floppy drive and a 20 MB slim hard disk in the CPU 2801 configuration. Its own display controller supported Olivetti monochrome and colour displays. Later expansion included 1 MB on-board memory and the ME903/MEM2852 memory board.
Hardware
- Processor
- Intel 80286, 8 MHz
- Memory
- 512 KB standard; 1 MB on-board documented
- Chipset
- Olivetti FE2000 proprietary logic
- Video
- Olivetti indigenous OGC display controller
- Floppy drive
- One 5.25-inch 1.2 MB drive in the documented CPU 2801 configuration
- Hard disk
- 20 MB slim hard-disk unit (Olivetti Setup type 2); controller at primary 1F0h / IRQ14
- Clock and CMOS
- MC146818-compatible calendar/CMOS with battery backup
- Expansion slots
- Seven bus positions; ME903/MEM2852 memory expansion remains unmodelled
Catalogue classification
- Form factor
- Desktop
- Mobility
- Stationary
- Processor generation
- 80286 class
- Graphics standard
- Olivetti Graphics Controller
- Storage interface
- Floppy drive, MFM
Research
This page separates documented hardware facts, behavior observed in original firmware, and the current fidelity of BluMach emulation.
Architecture and memory
Evidence: documented or confirmed hardware
- CPU and bus
Intel 80286 at an 8 MHz bus, with Olivetti FE2000 proprietary system logic.
- Memory
512 KB was documented for CPU 2801 and can be expanded to 1 MB on-board. With 1 MB installed, the recorded diagnostics observe 640 KB conventional plus 384 KB remapped extended memory. The ME903/MEM2852 expansion board is documented but not modelled.
- Video
Olivetti's own OGC controller, shared with related Olivetti systems. The current model exposes the aliases used by Customer Test, while an interactive alias retest remains pending.
- Storage
The service manual documents a 20 MB slim drive or a 40 MB full-height drive, with the controller at primary 1F0h, IRQ14 and DMA3. Olivetti lists the GO714 (WD1003-WA2, ST506/MFM with floppy) for the M28 with BIOS 2.07 or later; BluMach emulates it with the WD1003 and 615/4/17 geometry for the 20 MB profile.
BIOS and firmware
Evidence: observed in preserved firmware and boot testing
- Known revisions
Known 32 KiB BIOS pairs are PBUY/PBUX 2.09 and PBU6/PBU7 2.12. The 2.12 pair is the default because it is the latest locally validated set; the shipping BIOS for CPU 2801 is not yet established.
Emulation status
Evidence: current BluMach status; not necessarily a description of the original circuit
- Verified
Recorded validation confirms cold POST, RTC/CMOS, floppy boot and 1 MB memory. The catalogue profile uses the documented 512 KB commercial baseline and launches without proprietary media.
- Pending or approximate
The ME903 memory expansion does not exist. Warm reset, an interactive keyboard subtest and a video alias subtest remain open. The GO714 is emulated with the WD1003: its jumpers are not modelled, it stays at 1F0h and IRQ 14, the machine still provides the floppy controller, and it resets on a soft reset.
Sources
Preserved research material
Evidence: primary sources and research notes
- Original manual
- Olivetti CAP3 service guide.
- Original product brochure
- Dutch commercial brochure documenting the M28/20 configuration.