1Disk: Micropolis 2================ 3 4Micropolis MetaFloppy disks use MFM and hard sectors. They were 100 TPI and 5stored 315k per side. Each of the 16 sectors contains 266 bytes of "user data," 6allowing 10 bytes of metadata for use by the operating system. Micropolis DOS 7(MDOS) used the metadata bytes, but CP/M did not. 8 9Some later systems were Micropolis-compatible and so were also 100 TPI, like 10the Vector Graphic Dual-Mode Disk Controller which was paired with a Tandon 11drive. 12 13**Important note:** You _cannot_ read these disks with a normal PC drive, as 14these drives are 96tpi.The track spacing is determined by the physical geometry 15of the drive and can't be changed in software. You'll need to get hold of a 16100tpi Micropolis drive. Luckily these seem to use the same connector and 17pinout as a 96tpi PC 5.25" drive. In use they should be identical. 18 19Reading disks 20------------- 21 22Just do: 23 24``` 25fluxengine read micropolis 26``` 27 28You should end up with a `micropolis.img` which is 630784 bytes long (for a 29normal DD disk). The image is written in CHS order, but HCS is generally used 30by CP/M tools so the image needs to be post-processed. For only half-full disks 31or single-sided disks, you can use `-s :s=0` to read only one side of the disk 32which works around the problem. 33 34The [CP/M BIOS](https://www.seasip.info/Cpm/bios.html) defined SELDSK, SETTRK, 35and SETSEC, but no function to select the head/side. Double-sided floppies 36could be represented as having either twice the number of sectors, for CHS, or 37twice the number of tracks, HCS; the second side's tracks logically followed 38the first side (e.g., tracks 77-153). Micropolis disks tended to be the latter. 39 40Useful references 41----------------- 42 43 - [Micropolis 1040/1050 S-100 Floppy Disk Subsystems User's Manual][micropolis1040/1050]. 44 Section 6, pages 261-266. Documents pre-ECC sector format. Note that the 45 entire record, starting at the sync byte, is controlled by software 46 47 - [Vector Graphic Dual-Mode Disk Controller Board Engineering Documentation][vectordualmode]. 48 Section 1.6.2. Documents ECC sector format 49 50 - [AltairZ80 Simulator Usage Manual][altairz80]. Section 10.6. Documents ECC 51 sector format and VGI file format 52 53[micropolis1040/1050]: http://www.bitsavers.org/pdf/micropolis/metafloppy/1084-01_1040_1050_Users_Manual_Apr79.pdf 54[vectordualmode]: http://bitsavers.org/pdf/vectorGraphic/hardware/7200-1200-02-1_Dual-Mode_Disk_Controller_Board_Engineering_Documentation_Feb81.pdf 55[altairz80]: http://www.bitsavers.org/simh.trailing-edge.com_201206/pdf/altairz80_doc.pdf 56