• Midnight Mega
• News
• Installation
• Start
• Limitations
• Operation
• Project subfolders here on Github
  • llvm
  • Others
• Tools and experiments
  • Romlister
  • PC transfer
  • Handling PETSCII texts
• Requirements, project
  • Not yet in progress
  • Tasks
    • operational
    • string, screen handling
    • graphics
  • Bugs
    • recently fixed
    • faults
• C environment
  • Additions to mega65-libc
  • Additions to llvm-mos
• Changelog

Midnight Mega

A simple file commander and disk mounting programme.

Work in progress.

News

The current versions of Midnight Mega unfortunately are slowed down on purpose if you use a release version of the core software for your MEGA65. Specifically this is The file HICKUP.M65 which resides on your storage card.

You might temporarily install a newer HICKUP.M65 with a factory delivered R6 machine to get the full Midnight Mega experience. Should you stay as you are MM will prompt you what you miss, mainly speed.

Installation

Try only with backed up disks and .d81 ! The current state of this development will eat your files.

• Check the project out and dive into folder llvm.
• Use MOUNT "MIDNIGHT.D81" as programme disk.
• Optionally use MOUNT "DATADISK.D81",U9 as a torture disk. Or use copies of your own disks.

Start

Currently MIDNIGHTMEGA PRG is the only programme. You find it within MIDNIGHT.D81.

The earlier file DBGMIDNIGHTMEGA PRG to see an additional disk/track/sector/read/write in the lower left of the screen is no longer needed. The overlay is configurable in the setup which you can reach with the [F9] key.

The second file EMUMIDNIGHTMEGA PRG no longer provided was the same as DBGMIDNIGHTMEGA but with additional delays for each sector read and written. It was used to examine .d81 on storage card behaviours or in XMega65 from the Xemu emulators suite. Both otherwise being quite fast to look at. The delay feature currently is not available.

The additional output shows like D1T40S1 R where D1 is the chosen disk drive number (currently 0 for the left screen pane and 1 for the righthand one). T40 is the track, S1 the sector number currently in operation. So R is reading while W is writing the disk (image).

After starting the main programme MIDNIGHTMEGA is loading an SEQ file named MIDNIGHTMEGATEXT into the Attic RAM of your MEGA65 computer or XMega65 (Xemu) emulator. If it is unable to do so it will prompt you and cease to work. Hence both files are essential for the operation of Midnight Mega.

Limitations

• Midnight Mega is still in a beta testing release, and it is recommended to back up your data regularly.
• Please report any issues you find, and join the discussion on the #midnight-mega channel of the MEGA65 Discord.
• Also note that it only supports disk images and the internal floppy drive; it does not yet support external IEC drives.
• Since the left listing pane is always drive 0 and the right one 1 you have to set up both sides reasonably. In most cases drive 1 will not have a disk image mounted when you start Midnight Mega. This will give you a ping sound, a red screen border and the flashing message disk access error, displaying the list of available subfolders and disk image files on the storage card (image file) to be mounted instead.
• Should you try to mount a disk with illegal track/sector file chains or other erroneous data it will not be opened and you will be sent back to the storage card file selection instead. This is because Midnight Mega is currently unable to show incomplete directory structures. You may want to try accessing such disks in normal BASIC and optionally reformat to make them usable for Midnight Mega.

Operation

The following keymapping is also shown when opened by pressing the [F1] or [HELP] key.

• Most keys are shown in the footer bar
• [Ctrl][r] to rescan current file panel (left or right)
• Due to Hypervisor limitations .d81 image files can neither be copied as a whole nor be created, use [Mega][F3] to reach the MEGA65 freezer menu to do so
• [Mega][F5] copies all blocks (allocated ones if configured) of the selected side (left or right) to the opposite one, this will overwrite a whole disk (image) contents irrevocably
• [←] in the upper left of your keyboard can be used instead of the .. directory entry to climb to the parent directory
• Currently the left pane is always drive 0 and the right one drive 1, a later handling within the same drive is planned allowing you to copy files within one disk
• [F2] ([Shift][F1] on the MEGA65 of course) is used for both switching from a mounted .d81 to the selection within the storage card and back
• [F11] unmounts the current side to reach a real floppy drive. Bear in mind the MEGA65 in its factory delivered state has no hardware drive 1, so the right side unmount will greet you with an error message.
• [Mega][F3] opens the Freezer screen. It is an in-application alternative to using a longer press onto the [RESTORE] key. After coming back the application is rescanning the drives like it does if the [Ctrl][r] combination of keys is used to ensure updated disk contents
• [F7] is to create a subdirectory. [Mega][Shift][F7] to format the disk/image file completely. This only writes a few blocks, there is no low level format. Should you have difficulties regaining access to a disk through Midnight Commander please consider a real FORMAT from BASIC.

Project subfolders here on Github

llvm

The downloaded .7z file release from the llvm-mos Github repo is used in my own make batch file. In this folder I’m currently adding functionality to my little file manager project.

Please be aware currently Midnight Mega is in an unstable state, it might handle your .d81 and real disk drive inserted diskettes maliciously. Expect data loss. Feedback welcome as issue tickets.

Others

Previously present folders for KickC and Calypsi were removed.

Tools and experiments

Romlister

Shipped with Midnight Mega’s .d81 disk image file comes Romlister. This is a simple output page also available within Midnight Mega showing the versions of each MEGA65.ROM file on the storage card (image file). So it actually uses the MEGA65’s so called Hyppo functions to see the underlying FAT based file system.

PC transfer

Also in subfolder llvm you find a script xemu-image.bat. This is currently used to populate an empty storage card image file to be used in Xemu. It also allows to choose in between image files and real seriel/network connections towards the hardware. You may want to look into the lines to get some ideas for your own setup.

Handling PETSCII texts

midnightmegatext.src is a text file which gets converted into a SEQ file. Like this I can use screen output strings in a preformatted way. Within the source file you can see curly braces used for control characters and codes being intercepted by the programme’s code. The file is loaded at startup and the code reads each byte. After every line end (ASCII code 13) it expects a new string. The function being called thus sees over a hundred single fromatted text lines originating from within the file. This is supposed to make the actual programme file smaller to allow for more features. Currently still lots of strings are within the PRG file waiting for a transfer.

Requirements, project

Not yet in progress

• greyed out function keys will get implemented.
• function keys in the foot of the screen will be showing more modifier key combinations.
• storage card and file entry flags need to be handled outside of the dirent to further support illegal dirent attributes.
• Hyppo SD card handling as far as possible (writing not yet implemented on Hyppo side).
• Creation of .d81 image files currently unsopported by Hyppo.
• For llvm replace most fixed strings for screen output with their syntax. Maybe check how PETSCII differs from screen codes/attributes. Otherwise use the cc65 approach.
• Maybe reading of a setting file to get configurable personal preferences a go, a seperate setup programme could be added to the disk.
• [F1][Help] need to load a text file from the diskette and show the user, same routines to be used as for [F3].
• GEOS VLIR filenames and file types are not displayed correctly, neither are they supported nor rejected.
• Add the core’s .d64 support.
• In addition to .prg and .d81 create a ROM file with the programme to be used like so.

Tasks

operational

• copying of complete disk images, real diskettes respectively
• proof of concept accessing .d81 mount handling
• copying of single/multiple files in between real/virtual drives, mounted images
• Handling of subdirectories (sub-partitions of file type CBM) inside diskettes
• [Ctrl][u] to swap mount situation, mind swapping the complete attic too ☹
• ability to use the same drive number on both sides of the commander to copy files onto the same disk
• Full disk copy, meaning only within already mounted .d81 disk image files or with real floppy diskettes
• proof of concept abstraction layer real/virtual floppy image
• proof of concept reading floppy (sub-) directories
• proof of concept reading files, sectors, tracks
• proof of concept writing files, sectors, tracks
• refactoring for code runtime optimisation
• test data copy by exceeding the maximum number of allowed blocks
• unmounting to gain full access to the underlying real floppy drive is not yet implemented
• test unmounted drives, empty disks and other error handling
• handle errors when copying files from mounted .d81 in the storage card subdirectory, this currently writes illegal track numbers as blockchains
• remove dirent sectors if empty after file deletions, retain track chain
• involving the user to handle same name files/directories
• not all routines take care of changing header sectors if dived into sub-partitions, most of them are secured by an error message though
• Completing the routines to create subdirectories, strategy for consecutive tracks to first present the maximum size and to finally create
• Currently the subpartition startegy always heads for the biggest available chunk of consecutive empty tracks, even if a very low number is needed
• Speed up with now into a SEQ file outsourced strings
• Maybe change reading disk sectors completely to a tracked based cached reading like is done in Megasputm: https://github.com/ki-bo/megasputm/blob/main/src/diskio.c#L1555
• If track chains are created by other tools like Dirmaster or C1541 they may contain illegal track numbers, there should be dedicated error messages for it
• BAM and dirent blocks are read/written way too often. With the now cache for two disks (left and right) in place this can be optimised.
  A BAM flag could be used to only read it back in case disk operation need access to it/alter it.
  Also BAM and dirent should be handled in one go as the double logical sectors for both share same physical ones on a disk.

string, screen handling

• s[] and OPTION option are maybe data to put to different places, s[] could be the same pointer as p2sbuf
  also all little string places like disknames[] and fixed strings everywhere can be optimised
  strcopy() doesn’t consider strings filled with $0a as used in filenames and disk names
  There is an input string in both sides of the MIDNIGHT data structure which can be used
• Handling of $a0 as the space character replacement is done at screen output in conioextensions.c which isn’t ideal.
• Maybe unify strcopy alike functions to handle all variants and fixed length strings as well
• all variants of printing to the screen need to be replaced by only one to not have redundant code
• all texts at startup can now go to the help pages

graphics

• Text based GUI, Midnight/Norton Commander oriented
• show a status footer with number of blocks available
• better visualise disk and mounting errors
• message boxes for errors and warnings in different colours/sounds?
• Use different (grid?) colour when SD card content is shown
• Maybe replace some (most?) of the dialog boxes with a status bar
• On multiple selected entries present the user a nice sum of their total size
• How about those separator lines and graphics using DEL file type entries?
• Modifier key handling could be improved/optimised to treat keys different that don’t require modification at all.
• Flickering in Xemu when e.g. cursor up is performed multiple times because of how modifier keys are currently handled.
• Maybe costumise a font to have certain helping characters like an arrow down. Then also put all borders into the CBM standard font to make adtbm’s Christmas collection .d81 with its wavy lines appear (more) correctly.

Bugs

recently fixed

• Copying files into subdirs currently allocates BAM outside the subfolder tracks.
• The help file display routine is currently limited to one block of data instead of four for a full screen.
• Additional dirent blocks are placed outside track 40 and this is not what Commodore did.
• Additional file blocks are also placed within track 40.
• Updir within disk root folder unecessarily re-reads the headers
• After file delete BAM seems to be written in the according function as well as in nav.c
  better check with DEBUG on
• Storage card file deletion (also used for directories) takes place more than once, should be wrapped in a function.
• The disk controller always reads/writes two logical sectors at a time because of course it acts on physical 80 sectored dual sided media. The now abstraction make in no way optimal use of that.
  ✓ Either reading one sector could keep the other in a cache or UpdateSectors() could be optimised to read them all at once in a proper numeric order.
• dirent is currently not fully updated, additional sectors are currently not added automatically.
• dirent currently uses a full 255 bytes page of data which of course is completely unnecessary.
• dirent currently is read beginning with the first block of file entries not supporting the disk name block at track 40 sector 0.
• The yet state of development only uses the left file list so copy actually only duplicates files on the same disk
• BAM is only supported for one sector, tracks 41 to 80. therefore not yet covered.
• BAM is not yet in attic RAM, therefore multiple discs not cached.
• Improve handling of DEL type files.
• reading/writing .d81 always takes two logical sectors at once, writing of a single one should first read its accompaigning one.
• reading the last sector 39 results in side 1 and an invalid next track.
• If a file is only read the drive’s LED doesn’t switch back off. ~It seems this is done by _miniinit() which needs to be checked~ anyway.
• Multiple selected listed items are not properly named in confirmation dialog boxes.
• At some places the highlighted list item is used for the chosen action instead of the selected items.

faults

• If a disk has faulty sector chains (e.g. to sector 0) even [Ctrl][r] does not recover from that.
• When a .d64 is mounted Midnight Mega treats it as a .d81 and data is lost when it is being operated on. This state cannot be detected with Hyppo HDOS v1.2 and older.

C environment

Additions to mega65-libc

• are in file llvm/conioextensions.h and are quirky because of most in conio.c being static
• conio.c was copied to the llvm folder and massively edited to get rid of not needed stuff. This freed 3+ blocks of code.
• the full removal of KickC based include files from folder llvm/include

Additions to llvm-mos

• The following lines autodeclare DIRENTPAGELOW because such symbols seem not to be usable with inline assembly otherwise. Its values would be indetermined.

#define readdir_direntasm BLOCKDIRENT
__asm__(".set readdir_dirent, " XSTR(readdir_direntasm) );

Changelog

• v0.6.6-beta (shown as v2.2 on the filehost) fixes a major bug in the sorting routine for the shown entries reachable with [F9] Menu,
• v0.6.5-beta (shown as v2.1 on the filehost) reinitiating motor spin up on physical drive number change
• v0.6.4-beta (shown as v2 on the filehost) fix of GUI glitches and an added help text
• v0.6.3-beta (shown as v1.9 on the filehost) sorting dirents, renaming files/directories, drive LED handling
• v0.6.2-beta (shown as v1.8 on the filehost) dirent, the maximum number of entries is now 248. Thanks adtbm for the bug report.
• v0.6.1-beta (shown as v1.7 on the filehost) dirty fix for HDOS v1.2 users. Thanks to adtbm and deft for having tested and found bugs.
• v0.6.0-beta (shown as v1.6 on the filehost) Fixed disk read/write, removed splash message. Altered .md handling to create a table of contents using Pandoc. Edited help texts.
• v0.5.22-beta (shown as v1.5 on the filehost) Fixed create subdir and format disk, key combo for romlister has changed
• v0.5.21-beta (shown as v1.4 on the filehost) gives us subdirectories
• v0.5.18-beta (shown as v1.4 on the filehost) provides mounting support for Hyppo v1.2, HDOS v1.3. It is backwards compatible.