HIT_HMD2043 __ __ || || ||==|| I T _|| ||_ Harold Innovation Technologies "If it ain't a HIT, it's a piece of..." DCPU-16 Hardware Info: Name: HMD2043 - Harold Media Drive ID: 0x74fa4cae, version: 0x07c2 Manufacturer: 0x21544948 (HAROLD_IT) Document version: 1.1 Change history: 1.1: Added command for setting interrupt message. Fixed manufacturer id which was erroneously word-swapped. 1.0: Initial release. Description: The HMD2043 is the latest effort on the part of Harold Innovation Technologies to futurise the computing landscape of tomorrow; today! It is a high-quality disk drive made from the finest materials known to man. It supports a vast panopoly of disk formats: * HMU1440 - 1.44 MB 3.5" Harold Media Unit. Because of its amazing all-American construction, it will also support disks manufactured by other, inferior "technology" companies; YOU KNOW WHO YOU ARE! The drive incorporates unique "quality sensing" technology to identify low-quality disks, allowing the system to warn the user. But, I'm a big enough man to stoop to your level and... Waitaminute; I've just had an idea for a motorised stooping machine; Angela, get the engineers in here and turn this damn recorde -- Harold Lam, Founder and Chief Innovationist. Interrupt behaviour: The HMD2043 supports a number of HWI commands based on the value of the A register: 0x0000: QUERY_MEDIA_PRESENT If a supported disk is present in the drive, this sets the B register to 1. Otherwise, it sets the B register to 0. Media should be tested with the 0xFFFF command before use. 0x0001: QUERY_MEDIA_PARAMETERS Reads out the physical properties of the media. They are placed into registers as follows: B = Number of words per sector. C = Number of sectors. X = 1 if media is write-locked, 0 otherwise. 0x0002: QUERY_DEVICE_FLAGS Returns the internal device flags in the B register. The meaning of this field is defined in the UPDATE_DEVICE_FLAGS command. 0x0003: UPDATE_DEVICE_FLAGS Sets the internal device flags to the value of the B register. The available bit flags are, by bit number: 0: NON_BLOCKING - if set, all slow operations will be performed in "non-blocking" mode; that is, the hardware command will return control to the DCPU immediately and an interrupt will be issued upon completion. Note that other commands issued during a non-blocking operation will silently fail. Until the interrupt is raised, the device will NOT consider the non-blocking operation "complete". Before issuing a non-blocking command, be sure to set an appropriate interrupt message with SET_INTERRUPT_MESSAGE. 1: MEDIA_STATUS_INTERRUPT - if set, the device will raise an interrupt when the media status changes: new media is inserted or current media ejected. Before enabling media status interrupts, be sure to set an appropriate interrupt message with SET_INTERRUPT_MESSAGE. The default value is all bits set to zero. 0x0004: QUERY_INTERRUPT_TYPE The device will indicate the type of interrupt that it last raised by placing one of the following values into the B register: 0x0000: NONE - No interrupts have been raised yet. 0x0001: MEDIA_STATUS - Media status changed. 0x0002: READ_COMPLETE - Read operation completed. 0x0003: WRITE_COMPLETE - Write operation completed. The value of the A register will be changed to the error status of the event in question, not the error status of the QUERY_INTERRUPT_TYPE command itself. 0x0005: SET_INTERRUPT_MESSAGE Specifies the message the device should use for software interrupts. Takes one parameter: B = Interrupt number to use when interrupting the DCPU. If the device raises an interrupt before the message is set, it will default to using 0xFFFF. 0x0010: READ_SECTORS Reads a contiguous range of sectors into memory. The parameters are: B = Initial sector to read. C = Number of sectors to read. X = Start of in-memory buffer to read into. The length of time this command will take depends on the state of the drive and the physical parameters of the media in use. This operation may be performed in non-blocking mode. 0x0011: WRITE_SECTORS Writes a contiguous range of sectors to disk. The parameters are: B = Initial sector to write. C = Number of sectors to write. X = Start of in-memory buffer to read from. The length of time this command will take depends on the state of the drive and the physical parameters of the media in use. This operation may be performed in non-blocking mode. 0xFFFF: QUERY_MEDIA_QUALITY Determines the quality of the media inserted into the drive. It places this value into the B register. It has the following values: 0x7FFF: Authentic HIT media. 0xFFFF: Media from other companies. All commands replace the contents of the A register with a flag indicating whether the command succeeded or failed. The following result codes are defined: 0x0000: ERROR_NONE - The operation either completed or (for non-blocking operations) begun successfully. 0x0001: ERROR_NO_MEDIA - Operation requires media to be present. In long operations, this can occur if the media is ejected during the operation. 0x0002: ERROR_INVALID_SECTOR - Attempted to read or write to an invalid sector number. 0x0003: ERROR_PENDING - Attempted to perform a non-blocking operation whilst a conflicting operation was already in progress: the most recent operation has been aborted. Performance: Full-stroke: 200 ms Spindle speed: 300 RPM, 5 Hz using Constant Angular Velocity Maximum data transfer speed: 768 kbit/s, 48 kw/s Head position on media insertion: innermost track Head mode: full duplex [1] Time to seek to sector = floor( abs(target sector - current sector) / (disk sectors per track) ) * full stroke time / (disk tracks - 1) Time to read/write a sector = 1 / (spindle speed * disk sectors per track) Example times: 1.44 MB 3.5" Disk: Time to seek to adjacent track = 2.5 ms Time to read/write a sector = 11 ms Time to read/write entire disk = 16 s [1] The head is capable of reading/writing both sides of the disc at the same time.