{----------- Dandelion Processor Program - I/O Processor -----------
DESCRIPTION: Floppy Disk Task Definitions.
Jim JXF : 1-Sep-84 17:24:11: Add copyright notice
Jim JXF : July 27, 1982 10:28 AM: New IO Page Format
Jim JXF : May 21, 1982 7:12 AM: Change DmaFunc -- no mask needed
Roy RXO : February 24, 1981 12:24 PM
Dan dD : January 26, 1981 1:15 PM
File: FloppyDefs.asm
Stored: [Iris]<WMicro>DLion>FloppyDefs.asm
Written by Roy RXO .
Modification History:
- Created (January 2, 1981 12:02 PM)
- added Format parameters (January 8, 1981 1:56 PM)
- transferred Explanation from FloppyTask (January 9, 1981 3:29 PM)
- Tried to run at full speed by allowing the chip to read and write
runs of sectors. (January 12, 1981 10:49 AM)
- 8085 Interrupt mask definitions deleted (February 24, 1981 12:23 PM)
}
{ Copyright (C) 1981, 1982 by Xerox Corporation. All rights reserved.}
{ The Floppy Task interfaces with the Floppy Head in the CP, and the floppy
disk controller hardware. The task is activated when the CSBWatcher notices that
there is a non-zero IOCB pointer in the Floppy CSB (word 1). The task then inspects
the value of the command in the IOCB, and executes the appropriate command. After
the command is executed, the floppy task writes the Result word in the IOCB, updates
the Sector Count, does a Naked Notify, and then clears the IOCB pointer in the CSB.
Due to interleaving, the current value of IOCB.SectorCnt will not be correct after an
error completon of a sector command. This is because the sectors completed correctly
will not be adjacent. Thus, after a sector command completion error, the number of
sectors still to be done is corrected to reflect the minimum number of ADJACENT
sectors correctly done, and IOCB.SectorCnt is adjusted accordingly. The minimum number,
i.e. one sector for each interleave cycle in which at least one sector has completed
correctly, is used, since the calculation of the adjacent sectors completed corectly in
the last interleave cycle is complex, and was not deemed necessary for the code it
would require.
***** On January 23, 1981 interrupts were added and interleaving deleted. This allows the floppy to transfer data at full speed.
Floppy Disk CSB format - Addresses (in main memory) 14049 - 14050 (Hex):
word 0: Interrupt mask
word 1: Reset (-1 command inserted, IOP clears on completion)
Floppy Disk IOCB format - Addresses (in main memory) in n 64K bank:
Buffer description:
word 0,1: Long buffer pointer
word 2: Buffer size (in words)
Context:
word 3: Sector Length (in words)
word 4: bit 11: Troy/IBM' format, bit 12: Double/Single' density, other bits don't care
Disk Address:
word 5: Cylinder [0..76]
word 6: bits 0:7 - Head [0..1], bits 8:15 - sector number
word 7: Sector count
Operation result:
word 8: Result of operation
Command:
word 9: bit 0 - Single Buffer bit, bits 7:15 - Command
Note: Runs of sectors can be specified for Read Sector, Write Sector,
Write Deleted Sector, and Read ID.
word 10: Escape command (unused if Command#8)
1 = Clear DiskChange
The following two words are used only by the Format Track command.
word 11: Bits 0:7 - Encoded Sector length (00=>128 bytes,
01=>256 bytes, 10=>512 bytes, 11=>1024
bytes),
Bits 8:15- Sector Length/4
word 12: Bits 0:7 - number of fill chars in Gap Three
Bits 8:15- number of tracks to format
words 13:15 (reserved)
The following are the possible command values:
0 - NOP: Do a ForceInterrupt command and resturn the status
1 - Read Sector: Read a run of sectors on the disk. The run should not
cross a track boundary.
2 - Write Sector: Write a run of sectors on the disk. The run should not
cross a track boundary.
3 - Write Deleted Sector: Write a run of deleted sectors on the disk. The run
should not cross a track boundary.
4 - Read ID: Read a run of ID records on the disk.
5 - Format Track: Format the specified track.
6 - Recalibrate: Restore the disk.
7 - Initialize: Initialize the disk controller.
8 - Escape: Interpret the following word in the IOCB as a low-level command.
1: Clear Disk Change
Note: Runs of sectors can be specified for Read Sector, Write Sector,
Write Deleted Sector, and Read ID. Runs of operations are handled by
double buffering disk operations. A run of tracks (all on same side)
may be specified for the Format Track command. In that the command the
SectorCnt is the number of sectors per track.
IOCB Result Format:
This is the format of the Result word written in the IOCB by the IOP.
The Mesa Head will use this Result word to form the returned status value.
Bit 0: diskChange
Bit 1: 0
Bit 2: twoSided
Bit 3: DiskID (0 = SA800, 1=SA850)
Bit 4: error (an error completion occurred)
Bit 5: 0
Bit 6: recalibrateError
Bit 7: dataLost (only on Read and Write commands)
Bit 8: notReady
Bit 9: writeProtect (only on Seek, and Write commands, 0 otherwise)
Bit 10: deletedData (only on Read Sector command, undefined otherwise)
Bit 11: recordNotFound (on Read ID, Read Sector, Write Sector)
Bit 12: crcError
Bit 13: track00
Bit 14: undefined
Bit 15: busy (should never be 1)
Notes:
- Interleave factor has been hardwaired into the code as 2. Change by changing
in allocation of IntFactor.
Assumptions:
- Sector count in IOCB is [1..255]. A zero value wil be interpretted as 256.
Sector run should not cross a Track boundary (except Read ID).
}
; Floppy Task definitions:
; CP address info.
CPIOCBHi equ 0 ; 64K bank of IOCB addresses
; CSB indexes:
CsbWUMask equ 0 ; Interrupt mask in CSB (local)
; IOCB indexes:
; Local memory: byte index, main memory: word index.
IocbBufPtr equ 0 ; IOCB Buffer Pointer (low word) (local memory)
IocbBufPtrHi equ 2 ; IOCB Buffer Pointer (high word) (local memory)
IocbBufSize equ 4 ; IOCB Buffer Size (local memory)
IocbSectorLen equ 6 ; IOCB Sector length (local memory)
IocbMiscContext equ 8 ; IOCB miscellaneous context (local memory)
IocbCylinder equ 10 ; IOCB Cylinder (local memory)
IocbSector equ 12 ; IOCB Sector (local memory)
IocbHead equ 13 ; IOCB Head number (local memory)
IocbSectorCnt equ 14 ; IOCB Sector count (local memory)
IocbResult equ 16 ; IOCB Result (local memory)
IocbResultHi equ 17 ; IOCB Result (high) (local memory)
IocbCommand equ 18 ; IOCB Command (local memory)
IocbCommandHi equ 19 ; IOCB IocbCommand (high) (local memory)
IocbEscCommand equ 20 ; IOCB Escape Command (local memory)
; The following parameters are used only by the Format Track command
IocbEncSectorLen equ 22 ; IOCB encoded sector length
IocbQuarterSectorLen equ 23 ; IOCB (SectorLength)/4
IocbGap3Len equ 24 ; IOCB length of Gap 3 on disk
IocbSectorsPerTrack equ 25 ; IOCB number of tracks to format
CPIocbSectorCnt equ 7 ; IOCB Sector count (main memory)
MiscContextMask equ 18H ; IOCB miscellaneous context mask
nMiscContextMask equ 0FFH-MiscContextMask ; Compl. of misc. context mask
ErrorMask equ 8H ; Error bit in IOCB ResultHi
LostDataMask equ 1H ; LostData bit in IOCB ResultHi
HeadMask equ 1H ; Head mask in IOCB.Head
ClrDiskChgCmd equ 1 ; Escape command: Clear Disk Change
; 1797 Floppy Controller definitions:
; Commands:
ForceInt0Cmd equ 0D0H ; Force Interrupt, I = 0000 (no interrupt)
ForceInt1Cmd equ 0D1H ; Force Interrupt, I = 0001 (immediate interrupt)
ResCmd equ 8H ; Restore command (h=1, V=0, r1r0=0)
StepInCmdNoV equ 5AH ; StepIn command (h=1, V=0, r1r0=2) (slow enough for SA800)
SkCmd equ 1CH ; Seek command (h=1, V=1, r1r0=0)
SkCmdR1 equ 1DH ; Seek command (h=1, V=1, r1r0=1)
SkCmdNoV equ 1AH ; Seek command (h=1, V=0, r1r0=2) (slow enough for SA800)
RSectorCmd equ 080H ; Read Sector command (E=0) (1793)
WSectorCmd equ 0A0H ; Write Sector command (E=0) (1793)
RAddrCmd equ 0C0H ; Read Address command
RAddrDataLen equ 3H ; Read Address data length (words)
DeletedDataMask equ 1H ; Deleted data bit in WriteSector command
nDeletedDataMask equ 0FFH-DeletedDataMask ; Complement of mask
Type2SMask equ 2H ; S bit flag mask in Read/Write Sector Cmd (1797)
nType2SMask equ 0FFH-Type2SMask ; Complement of S bit flag mask
; Status bits.
; All types
FDCNotReady equ 80H ; Not ready
FDCCRCError equ 8H ; CRC error
FDCWrProt equ 40H ; WriteProtect
FDCBusyMask equ 1H ; Busy Status bit
; Type I:
FDCSeekError equ 10H ; Seek error
FDCHeadLoad equ 20H ; HLD and HLT
FDCTk0Mask equ 4H ; Track 00 bit mask in status
; Type II and III:
FDCRNFMask equ 10H ; Record Not Found
FDCLostData equ 4H ; Lost Data
FDCDRQMask equ 2H ; Data Request Status bit
; Error Masks for Type I commands
Type1ErrorMask equ FDCNotReady+FDCSeekError+FDCCRCError+FDCBusyMask
Type1HardMask equ FDCNotReady+FDCBusyMask
; Error Mask for Type II read commands
ReadErrorMask equ FDCNotReady+FDCRNFMask+FDCCRCError+FDCLostData+FDCBusyMask
ReadHardMask equ FDCNotReady+FDCBusyMask
; Error Mask for Type II write commands
WriteErrorMask equ FDCNotReady+FDCWrProt+FDCRNFMask+FDCCRCError+FDCLostData+FDCBusyMask
WriteHardMask equ FDCNotReady+FDCWrProt+FDCBusyMask
; Constants for FDCState:
;DisableFDC equ 80H ; Enable Waits, Disable controller, Disable Drive, defined
; in "SysDefs"
DefFDCStateVal equ 85H ; Enable Waits, Enable controller, Enable Drive
; Side=0, DDen = 0
DDenMask equ 8H ; Double density bit in FDCState
Side1Mask equ 20H ; Side 1 mask in FDCState
nSide1Mask equ 0FFH-Side1Mask ; Complement of Side 1 mask in FDCState
DriveSelectMask equ 1H ; Drive Select mask in FDCState
nDriveSelectMask equ 0FFH-DriveSelectMask ; Complement of Drive Select mask
PreCompStart equ 43 ; First track to have PreComp in double density
FDCEnPreCompMask equ 40H ; Enable PreComp mask in FDCState
nFDCEnPreCompMask equ 0FFH-FDCEnPreCompMask ; Complement of Enable PreComp mask
; FDC Status register (external) definitions.
FDCIntMask equ 80H ; FDC Int Req in IntReq register
DiskChangeMask equ 80H ; DiskChange mask in status register (external)
FDCEndCountMask equ 40H ; FDC end count in status register (external)
; Masks for Result word.
; 1's in mask indicate where nothing is tobe OR'd into Result.
Type1ZeroMaskLo equ 20H
nType1ZeroMaskLo equ 0FFH-Type1ZeroMaskLo
Type1ZeroMaskHi equ 4FH
nType1ZeroMaskHi equ 0FFH-Type1ZeroMaskHi
Type2ZeroMaskLo equ 06H
nType2ZeroMaskLo equ 0FFH-Type2ZeroMaskLo
Type2ZeroMaskHi equ 4FH
nType2ZeroMaskHi equ 0FFH-Type2ZeroMaskHi
RecalibrateErrorMask equ 2H ; Recalibrate Error in DiskStatusHi
; Dma defs.
FloppyChannelMask equ 1H ; Floppy is channel 0
OutDmaFunc equ DmaFuncRead ; Read memory
InDmaFunc equ DmaFuncWrite ; Write memory
END FloppyDefs