Apple IIgs #26
ROM Revision Summary
Revised by Matt Deatherage (September 1989)
Written by Rilla Reynolds (October 1987)
This Technical Note summarizes revisions to the Apple IIGS ROM.
Changes since November 1988: Revised to cover ROM 3.
Apple currently supports two configurations of the Apple IIGS ROM, ROM
1 and ROM 3. In August 1989, Apple IIGS computers began shipping with a
256K ROM, referred to as version 3 or ROM 3 (ROM 2 was skipped since there
was already enough confusion about the first version, ROM 0, and the
second version, ROM 1). System Software continues to support ROM 1, but
it no longer supports ROM 0. Authorized Apple dealers can upgrade older
systems (i.e., machines with serial numbers lower than E704...) to ROM 1
upon request.
ROM 1 requires System Software 2.0 or later, while ROM 3 requires
System Software 5.0 or later. Although applications may work using older
system software releases, they may not function properly due to the
coordination of system software and ROM revisions.
Changes from ROM 0 to ROM 1
ADB
- Absolute ADB devices are now supported correctly.
- ADB fatal system error code is now $0911 instead of $0400.
- ADBReset routine now delays about 160 microseconds before reading
the buttons.
- ADBStatus TRUE is now $FFFF instead of $0001.
- All ADB error codes now include the tool number.
- SRQrmv no longer crashes when you make the call with a command
pending.
AppleDisk 3.5
- AppleDisk 3.5 Macintosh block reads and writes now work as documented.
- Extended status call now returns bit 0 = 1 if AppleDisk 3.5 media
has been switched since the last READ, WRITE, or FORMAT.
- New AppleDisk 3.5 status calls have been implemented to get
internal variable and work buffer starting addresses.
AppleTalk
- Link Access Protocol (LAP) inter-packet gap now handles added SCC
delay.
- Name Binding Protocol (NBP) now considers uppercase and lowercase
characters identical.
- A nonexistent protocol no longer hangs the dispatcher.
Desk Manager
- SaveScreen and RestoreScreen now work.
Event Manager
- Now auto-key events are not posted in the queue unless the queue is
empty.
- EMStartUp and EMShutDown code has been optimized.
- Event Manager now returns an error instead of crashing when there is
an attempt to post an invalid event.
Integer Math
New Changes:
- Optimized the multiply routine.
RAM patches moved to ROM:
- Changes to FixMul, FixRatio, and SDivide.
- SDivide recovers from a divide by zero operation.
- New calls: FracMul, FixDiv, FracDiv, FixRound, FracSqrt, FracCos,
FracSin, FixATan2, HiWord, LoWord, Long2Fix, Fix2Long, Fix2Frac, Frac2Fix,
Fix2X, Frac2X, X2Fix, X2Frac.
Memory Manager
- Optimized Purge and Compact for banks 0 and 1 and moved from RAM to
ROM.
- RAM patches and enhancements moved to ROM.
- RAMdisk now returns bytes transferred count on DIB call.
- SetHandleSize makes a handle temporarily unpurgeable while changing
handle size.
Miscellaneous Tools
RAM patches and enhancements moved to ROM:
- AbsClamp fixes.
- Battery RAM routines work if data bank is set to a bank other than
bank data is in.
- Firmware entry calls now return processor status in high byte
instead of low byte.
- GetAddr with ref number $000E returns SerFlag address for SCC
interrupts (useful if not using serial firmware).
- ID manager can reuse discarded IDs.
- Keyboard interrupts now enable VBL interrupts.
- Munger now works with 1-char strings and returns with A=0.
- New SysBeep call.
- PackBytes and UnpackBytes return with A=0.
- ReadBParam and ReadBRAM error codes corrected.
- WriteBParam and WriteBRAM do not return error codes (this is a
documentation change).
- WriteTimeHex Bad Parameter error code is now $31.
Monitor
- 80-column screens maintained if break occurs and Pascal protocol
in effect.
- AppleSoft tabbing in 80-column mode now works correctly.
- Control Panel's Maximum RAM Disk Size increased to 8128K instead
of 4096K.
- Firmware version number returned is $1 instead of $0.
- Interrupts now disabled during paddle read routines.
- Interrupts re-enabled after fatal system error (for debug DAs).
- Mouse clamps with positive minimum and negative maximum works
(e.g., $6000 min, $8000 max).
- New monitor command, pound sign (#), installs monitor entry and memory
peeker classic desk accessories (unless already installed), accessible via
the Control Panel. Reinstalled automatically on reset; disabled by power
off only.
- New monitor command, Control-N, clears m, e, and x bits for native
mode. (Control-R still switches to 8-bit, emulation mode.)
- RESET entry point at $00FA62 sets state register to $0C and shadow
register to $08.
- Shadowing of the Super Hi-Res area in Bank 1 is no longer enabled
automatically.
- WAIT routine now always exits with C=1.
QuickDraw II
RAM patches and enhancements moved to ROM:
- 640-mode pen masks now work when portRect origin not a multiple of 8.
- Arcs, ovals, and round rects can be drawn across bank boundaries.
- Changes to round drawing routines: PPToPort, GetFontLore,
GetROMFont, and InflateTextBuffer.
- Current bank bytes 100...106 no longer modified by scaling and
mapping calls.
- FontFlags 1 and 2 added for pen width and color control.
- FramePoly returns with A=0.
- GetPort returns all four bytes of GrafPort.
- HideCursor and ShowCursor work correctly with obscured cursor.
- MapRgn now works on rectangular regions.
- Pixel painting routines support QuickDraw Auxiliary Tool Set
stretching and shrinking.
- PPToPort now clips correctly to the current portRect.
- QDStartUp and QDShutDown save and restore the scan line interrupt
vector.
- RectInRgn bug fixed.
- ScrollRect works when the ClipRgn and VisRgn are not rectangular.
- SetSysFont works.
- StdPixels now returns with A=0 if the pen is not visible.
- Text underline bug fixed.
- TextBounds works.
New QuickDraw changes:
- Busy flag now maintained correctly by ClosePort, OffsetRgn, InsetRgn,
KillPoly, FillRect, FrameOval, PaintOval, EraseOval, InvertOval, FillOval,
FrameArc, PaintArc, EraseArc, InvertArc, FillArc, FrameRRect, PaintRRect,
EraseRRect, InvertRRect, and FillRRect.
- Cursor appears in correct Super Hi-Res mode as determined by the
low byte's bit 7 (320/640) of the MasterSCB.
SANE
- Elems now can be called from any part of memory.
- HALT exception jumping through the incorrect vector fixed.
- Integer overflow during conversion reported.
- STATUS call moved to ROM.
Scheduler
- Scheduler now accepts a flush function call.
- Task-handling RAM patch (on System Disk 1.0 and later) moved to ROM.
Serial I/O
- First character after an XON is no longer trashed when buffering
is not enabled.
- If serial mode bit 17 = 1, parity and framing error suppression
are defeated.
- Parity, baud, and data format commands work with buffering.
- STATUS call will not report that a character is ready if the
character arrives with a parity or framing error.
- STATUS call works correctly with XON/XOFF protocol.
SmartPort
- PR#5, following a PR#5 with I/O error (i.e., no disk in drive),
now boots as expected.
- SmartPort manipulates only Slot 6 motor on detect so the IWM can
run in fast mode.
Sound
- Fixed bug in FFStopSound call.
- Fixed low-level RAM read/write bug.
- Interrupts are disabled when the internal bell is active.
- Interrupts no longer need to be disabled when accessing sound RAM.
- New sound diagnostics with the following error codes: $0C001 = failed
RAM data test, $0C002 = RAM address test, $0C003 = register data test, and
$0C004 = control register test.
- Sound Manager RAM patches and enhancements moved to ROM.
Text Tools
RAM patches moved to ROM:
- RAM patches moved to ROM for Writing and ErrorWriting routines.
- TextInit Illegal device error now is in 16-bit mode instead of 8.
Tool Locator
- Optimized tool dispatcher.
- ROM tools present on a memory expansion card are installed.
Changes from ROM 1 to ROM 3
ROM 3 is 256K (double the size of ROM 1) and contains several tools which do
not exist in ROM 1. The patch file TS3 fixes known bugs in ROM 3 which were
discovered after it was frozen. ROM 3 tools are basically System Software 5.0
tools, and the System Software 5.0 documentation covers these tools in detail.
This Note only documents non-tool changes.
AppleDisk 3.5 and SmartPort
- Use new routines for all block reads to fast RAM to eliminate
double buffering.
- The extended DIB status call returns the device subtype byte $C1.
- Fixed anomalies described in SmartPort Technical Note #6, Apple IIGS
SmartPort Errata.
- Fixed a ROM 1 bug that caused Write Protected to be returned with
higher priority than Device Offline for the ProDOS STATUS call.
AppleTalk
- AppleTalk moved to slots 1 and 2 from slot 7.
Control Panel CDA
- The original Options menu is now the Keyboard menu and does not contain
mouse parameters.
- A new Mouse menu is present. The new keyboard microcontroller allows
finer control of mouse tracking, so a selection procedure better than yes
or no is present. Parameters are also available to set the keyboard mouse
feature, which allows the numeric keypad to emulate a mouse.
- Added an option to resize the RAM disk on the next reset in the RAM
Disk menu. This option resets to No after one reboot and resizing so the
RAM disk is not accidently reformatted on every boot thereafter.
- If slot 7 is set to AppleTalk, the Control Panel displays a warning if
neither slot 1 nor slot 2 is similarly set.
- The Printer Port and Modem Port menus now display only those parameters
that may be changed if AppleTalk is the selection for those ports.
- The RAM disk no longer has minimum and maximum settings, but rather
one RAM disk size setting.
Monitor
- Enhanced memory searching commands to automatically cross bank
boundaries.
- Added Step and Trace debugging functions.
- Now provide vectors for the same functionality as the GS/OS System Service
calls MEMORY_MOVER, DYN_SLOT_ARBITER and SET_SYS_SPEED in bank $E1.
- Now resize the RAM disk when the system is rebooted with the
Control-Open Apple-Shift-Reset key combination.
- Handle text page 2 shadowing and power-up bits in the new CYA chip.
- Flash the border if the sound volume is set to zero and a beep is
necessary.
- In ROM 1 and earlier, the Miscellaneous Tools mouse firmware called
the 8-bit mouse routines in the $C400 space to do the work. In ROM 3, the
8-bit routines call the 16-bit routines to read the hardware. This change
effectively means those programs which use 16-bit mouse calls (including
desktop applications through the Event Manager) may use the mouse when
slot 4 is set to Your Card.
- Slots 1 and 2 may now be set to Printer, Modem, AppleTalk, or Your
Card. With System Software 5.0, slot 7 does not need to be set to
AppleTalk to use an AppleTalk network, although one can do it for
compatibility. There is no transparent printing firmware in slot 7.
- The Alternate Display Mode CDA no longer sets the system to fast speed
when normal speed is selected in the Control Panel.
- Added a new command, {val}=V, to set the video screen display I/O
switches when resuming a program.
- Control-T command now works as a toggle -- executing it once changes
to text mode, but now executing it again switches back to the previous
video mode You may change this saved video mode with the =V command.
- Battery RAM value $59 now controls the presence of the Visit Monitor
and Memory Peeker CDAs. If this byte has the high bit set at boot time,
the CDAs are automatically installed.
- The Monitor and Memory Peeker both allow the use of Control-X to
terminate a long display (i.e., a handle list or memory dump).
Serial I/O
- XON and XOFF are no longer sent with the high bit set when buffering is
enabled.
- Terminal mode cursor is more consistent with the rest of the system.
- Extended Interface calls now return errors in the carry and the
accumulator.
Toolbox
The following tools are now in ROM:
- Window Manager
- Menu Manager
- Control Manager
- Line Edit
- Dialog Manager
- Scrap Manager
- Font Manager
- List Manager
Further Reference
This and all of the other Apple II Technical Notes have been converted
to HTML by Aaron Heiss as a public service to the Apple II community, with
permission by Apple Computer, Inc. Any and all trademarks, registered and
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