59 lines
2.5 KiB
Plaintext
59 lines
2.5 KiB
Plaintext
Known issues with the emulator:
|
|
|
|
Emulation Fidelity:
|
|
|
|
- Disk emulation. The emulator is not very realistic. It handles almost
|
|
all non-copyprotected disk access okay, but copyprotected or diagnostic
|
|
programs may be confused by our drive, which magically spins at precisely
|
|
the optimal speed. (see Specific Programs, below).
|
|
|
|
- Medium Resolution graphics. This is a rarely used //e mode that is to
|
|
Low-Res what 80 Column text is to 40 column text. We don't support it as
|
|
yet, although it should be relatively simple.
|
|
|
|
- We don't emulate the //e's vertical blanking interval detection feature.
|
|
This is on the TODO list.
|
|
|
|
Graphics:
|
|
|
|
- Composite graphics artifacts are not emulated. This is on the TODO list.
|
|
|
|
- B/W color setting does not apply to lores or double hires. This
|
|
generally is not an issue in practice though, as it's really only needed
|
|
to avoid color fringing in b/w hires images.
|
|
|
|
- Double Hires mode is always 140x192 color. Some applications use it as
|
|
a 560x192 b/w display however. Note that most applications indicate
|
|
which mode they want using the high bit of the dhires data bytes, so it
|
|
wouldn't need to be a preferences setting.
|
|
|
|
- If an 80-column mode is selected in the low-res emulator, nothing will
|
|
be written to the display -- the image from the last video mode will
|
|
remain on the screen. If a menu is brought up it will `stick'. This may
|
|
make people think the emulator crashed, although it will recover if the
|
|
application returns to 40-column mode.
|
|
|
|
Keyboard:
|
|
|
|
- Presently, the Backspace key is interpreted as Left-Arrow (Code 0x88).
|
|
It could be argued that it should be interpreted as Delete (Code 0xff)
|
|
instead. Real Apples had no seperate Backspace key, but the //e's Delete
|
|
key was in an analogous position to the PC's Backspace). The PC
|
|
keyboard's Delete is assigned to 0xff (in //e mode).
|
|
|
|
Specific Programs:
|
|
|
|
- Some programs (Computist's Nibbler, Sword of Kadash Master copy for
|
|
example) lock up. It appears (in debugger) that they are reading the disk
|
|
with the motor off. Perhaps they pulsed the real Apple's drive motor to make
|
|
it turn slower?
|
|
|
|
- ProDOS will refuse to format disks, claiming that the disk is too slow.
|
|
|
|
- ``Alternate Reality: The City'' seems to get jammed, rapidly changing
|
|
the video mode. I'm not sure if this is a real failure, or just a special
|
|
effect that takes longer than I'm willing to wait to finish (mode switches
|
|
would be much faster on a real Apple.) I can get into the program
|
|
with some nontrivial debugger manipulation to `short out' the offending loops.
|
|
|