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+--- Thread: Microbee (Mitac) Portable computer BIOS rom and MS-DOS 3.11 disk (/thread-771.html)
Microbee (Mitac) Portable computer BIOS rom and MS-DOS 3.11 disk - ChickenMan - 06-02-2024
Thanks to vivid for reminding me that I hadn't dumped the BIOS eprom from my Microbee (Mitac) Portable computer.
I can see why I hadn't dumped them in the past as the BIOS is located under the 5.25" floppy drive so a bit of dismantling needed to get to it. It also has a separate CGA Graphics controller card that was very accessible. The BIOS was in a 27128 eprom while the CGA was in a 2764.
The BIOS was labelled MICROBEE VBIOS R1.04 and CGA controller was dated 1986 REV: 1.00. With the Floppy drive lifted, the motherboard looks like this -
The Microbee Portable Computer was a re-badged Mitac MPV160C made in Taiwan, It uses an 8088 CPU (mine has an OKI M80C88 which is under the CGA card) with 256k ram (expandable to 640k with 256k ram chips), floppy controller, printer port, keyboard interface, two RS-232 ports, game port, colour/graphic RGB connector and Composite video connector. MS-DOS compatible running ver 3.11. We have the manual for the Mitac MPV160C as supplied with the unit in the Repository, so check it out for further information.
Thanks also to MbeeTech for making available a boot disk for the Microbee Portable, a 5.25" 40 track 360k IBM disk that read 100% error free in a Floppyio.
So in the MbeeTech Repository in the Microbee\Software\ROMs\Miscellaneous folder we placed
microbee_mitac_portable_BIOS_v1.04.bin
microbee_mitac_portable_CGA_v1.00.bin
microbee_mitac_portable_msdos_3.11.dsk <-- in the Microbee\Software\System_disks folder
RE: Microbee (Mitac) Portable computer BIOS rom and MS-DOS 3.11 disk - MbeeTech - 08-02-2024
Hi Chickenman.
I just wanted to ask about the HD controller? If you are referring to the board mounted on top of the main PCB in your photo, with the ROM
under the power wires that go to the 5.25" drive, then that is actually the CGA graphics card.
RE: Microbee (Mitac) Portable computer BIOS rom and MS-DOS 3.11 disk - ChickenMan - 09-02-2024
Arr I think your right I thought the Mitac card connected to the 50 way out the side, I now see it just so happens to be next to the card and not actually connected to it. Will amend the files. Thanks.