SmartDisk II: SmartPort emulation (hard disk)

In this mode the SmartDisk II is not a floppy drive. It is a SmartPort device with up to four volumes. Each volume is a ProDOS image file on your SD card.

The Apple II sees four units on the SmartPort bus. It reads and writes blocks of 512 bytes, and the board reads and writes the image file.

1. What it emulates, and on which machines

Machine	How you use SmartPort
IIc (ROM 4.x)	SmartPort port, as for a Disk II
IIgs	SmartPort port; a IIgs boots SmartPort images, also when you start them from the Smartloader (Smartloader)
II+, IIe	With a SmartPort card: Liron, SoftSP6 or Yellowstone

The cable and the connectors are on the hardware page. The list of machines is on the compatibility page.

2. What it needs on the card, and which files it accepts

The card must be FAT32 with 32 KB clusters (SD card preparation). If it is not, the OLED shows CLUSTER NOT 32K at power up.

Extension	What it is	Rule	Write
.po	raw blocks in ProDOS order, no header	the size is a non-zero multiple of 512 bytes	yes
.hdv	the same as .po	the same	yes
.2mg	a 2IMG file: a 64 byte header, then the blocks	the header must agree with the file (data offset, length, block count); a block count of 0 is taken from the file size	yes, unless the file is locked

Other points:

• The extension can be in upper or lower case. Game.Po works.
• 2MG details. An image of nibbles (a 5.25 inch disk) is refused. An image in DOS order is accepted and served as ProDOS blocks, so ProDOS finds the volume damaged. A locked flag in the header makes the unit write protected. A header with no block is refused.
• Size. A ProDOS volume holds at most 65,535 blocks (32 MB). That is the size Create disk makes for HD 32M. The board does not refuse a larger image.
• Not accepted: .dsk, .do, .woz, .nic, .dc42, .img. A 5.25 inch DOS 3.3 disk goes to the Disk II emulation (Disk II emulation).
• A file with the read-only attribute, or a locked 2MG, is mounted write protected: the unit refuses writes.
• The file list works as for the Disk II: it hides names of 3 characters or fewer, names that start with a dot, and hidden or system files. A folder lists its first 255 entries.
• The path of the image of each slot is saved in the configuration file. An empty slot stays empty.
• You can make blank and bootable images on the board. Create disk offers ProDOS images as .po, .2mg and .hdv (Create disk and image formats).

3. How to use it from the board

The screens are on the OLED screens page. Day to day use is on the usage guide.

1. Choose the emulation. Open Settings > Emulation type, choose Smartport HD and press RET. The board restarts in SmartPort. The main menu then offers File manager, SMARTPORT and Settings.

   

2. Open SMARTPORT. The SmartPort page shows the four slots, one per line:

   

   • 1:NAME is a slot with an image. The name is the file name without its extension, 14 characters at most.
   • 3:[SELECT] is an empty slot.
   • The slot that boots shows * instead of its number.
   • UP and DOWN go round the four slots and a fifth position, which selects nothing. The selected line is inverted.
   • Each time the Apple II sends a command, the ball in the top right corner turns. The letters RD, WR or I appear on the line of the unit: read, write or status.
3. Work with a slot that holds an image. ENTER opens Smartport Image:

   

   • Unmount image empties the slot.
   • Select image chooses another image for the slot (see step 4).
   • First to boot makes this slot the boot volume. The board saves the choice at once.
   • Toggle favorite adds the image to the favorites, or removes it.
4. Fill an empty slot. ENTER on the slot asks Select image from with Favorites and File manager. Pick the file. The board asks Mounting: NAME with YES selected. ENTER on YES saves the path and mounts the image.

   

5. Restart the Apple II so that it sees the change (see “Changing an image while the Apple II runs”, below).

If the board cannot mount a file, the OLED shows MOUNT FAILED. With Sound effect on, you also hear two beeps and a falling tone.

Options of this emulation

Option	What it does	Default
Boot Img Index	The volume the Apple II boots from (1 to 4). ENTER goes round the values.	1
Sound effect	A short click for each block the Apple II reads or writes, a click on the keys, and an insert or eject sound when an image comes in or goes out.	off
Screen saver	The display goes off after 30 seconds without a key.	off
Log to SD	Also writes the log to SMARTDISK.LOG on the card.	off
SP resync 2 edges	Changes how the board reads the packets the Apple II sends: it restarts its bit sampler on both edges of the data line, not only on the rising edge. It takes effect when the board restarts. Leave it off unless you have a SmartPort problem that nothing else fixes.	off

The list also has Clear prefs, Clear favorites and Make filesystem. Every option is explained on the settings page.

4. How it behaves

The boot volume and the unit numbers

• After a bus reset, the Apple II sends an INIT command to each device in turn, and each device takes the next unit number.
• The SmartDisk II answers for four units, whether they hold an image or not. A unit with no image answers as a drive with no disk.
• The boot volume is the slot that gets the first unit number, so the Apple II finds it first and boots from it. The other slots follow in order and wrap round.
• A new Boot Img Index applies the next time the Apple II sends INIT, that is, after a bus reset or a restart of the Apple II.
• After the Smartloader hands over, only one unit holds an image: the image you chose, in slot 1. The saved paths of the four slots are not used. Keep Boot Img Index at 1 when you start through the Smartloader. With another value the Apple II looks first at a slot that is empty.

What a unit looks like to the Apple II

Item	What the unit answers
Name	SMARTDISKHD followed by the unit number, 12 characters
Block size and count	512 bytes; the size of the image in blocks
Write protection	The unit says it is write protected when the file is read-only or the 2MG is locked
No image	The unit says there is no disk
Commands	STATUS, READBLOCK, WRITEBLOCK, FORMAT, CONTROL and INIT, with their extended versions

Writes

• A write goes straight to the image file. The card holds the block when the Apple II gets its answer.
• A write beyond the end of the image gives an I/O error. A read beyond the end gives a bad block error.
• No setting turns SmartPort writes off. To protect an image, give the file the read-only attribute on your computer, or set the locked flag of a 2MG.

Eject from the Apple II, unmount from the board

• An eject from the Apple II (the Finder, a ProDOS utility) takes the disk out of the unit. The unit then answers that there is no disk until you mount an image from the board.
• Unmount image on the board empties the slot.

Changing an image while the Apple II runs

Each time you mount an image from the menu, the board mounts all four slots again between two commands. The Apple II is not told that an image changed. There is no “disk switched” signal, so a program that keeps a list of volumes (the GS/OS cache, the Finder) does not notice.

5. Limits and known issues

Point	What to know
Changing an image while the Apple II runs	The Apple II is not told. Restart it (see above).
Image size	A ProDOS volume holds at most 65,535 blocks (32 MB). Create disk makes images of that size.

If something goes wrong, see Troubleshooting, FAQ and the log.

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