myoldmac.net - Apple IIc F.A.Q.
Apple IIc: Existing Versions

Apple IIc - Existing Versions

Apple II
Technical Notes
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Developer Technical Support
Apple IIc #7: Existing Versions

Revised by: Matt Deatherage November 1988
Written by: Guillermo Ortiz November 1987

This Technical Note describes the main differences between the five different
IIc ROM versions which encompass the original IIc and four revisions.
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Original Apple IIc ($FBBF = $FF)

o Can use the IIc external drive only
o No AppleTalk firmware
o PR#7 boots the second drive
o Mouse firmware maps to slot 4
o Serial firmware does not mask incoming linefeed characters
o Serial firmware does not support XON/XOFF protocol

3.5 ROM Apple IIc ($FBBF = $00)

o Can use the IIc external drive and the UniDisk 3.5 drive
o AppleTalk firmware maps to slot 7
o PR#7 returns the message "AppleTalk Off Line"
o Mouse firmware maps to slot 4
o Serial firmware defaults to mask all incoming linefeed characters
o Serial firmware supports XON/XOFF protocol

"Memory-Expandable" IIc ( $FBBF = $03)

o Can use the IIc external drive, the UniDisk 3.5 drive, and the IIc
Memory Expansion Card
o Mouse firmware maps to slot 7
o No AppleTalk firmware
o PR#7 kills the system
o Serial firmware defaults to mask all incoming linefeed characters
o Serial firmware supports XON/XOFF protocol

Revised "Memory-Expandable" IIc ($FBBF = $04)

Same as Original Memory-Expandable, plus:
o Keyboard buffering firmware bug fixed
o Firmware returns correct information when the Memory Expansion Card is
not present

Apple IIc Plus ($FBBF = $05)

o Can use the external IIc drive, the UniDisk 3.5 drive, the Apple 3.5
drives, but not the original IIc Memory Expansion Card.
o Contains a Memory Expansion Card connector
o 3.5" internal drive replaces 5.25" internal drive
o Mouse maps to slot 7
o PR#7 kills the system
o 4 MHz 65C02 microprocessor
o Accelerator chip and static RAM cache permit operation up to 4 MHz
o Keyboard replaced with Apple Standard Keyboard (minus numeric keypad)
o Internal power supply
o Internal modem connector
o Serial ports refitted with mini-DIN 8 connectors
o Headphone jack has been removed
o Volume control relocated above the keyboard
o 40/80 column switch replaced by keyboard (Sholes/Dvorak) switch

Further Reference
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o Apple IIc Technical Reference Manual, Second Edition
o Apple IIc Technical Note #5, Memory Expansion on the Apple IIc
o Apple IIc Technical Note #6, Buffering Blues
o Apple II Miscellaneous Technical Note #2,
o Apple II Miscellaneous Technical Note #7, Apple II Family Identification
o Apple II Miscellaneous Technical Note #8, Pascal 1.1

Apple //c Series - Info Source: www.mess.org

Known Issues:
Requires full keyboard emulation. At startup, full keyboard emulation mode is enabled by
default. Whilst in full keyboard emulation mode, some key associated functionality may be
disabled (like the ESC key for EXIT). The keyboard emulation mode is toggled using the
scroll_lock key.

History and Trivia:
Apple "][", Apple "II", Apple "//" - Which is correct?
"][", "II", and "//" tend to be used pretty much interchangably for any model of Apple II computer, although, practically speaking, there are a few usages which may provoke a correction. "][" is the original Apple II symbol. It appears on all early II's and II+'s as well as on the Disk ][ drive. It is, easily, the most attractive and distinctive II symbol; but, it is also associated with old Apple II's. The "//" usage is generally associated with the "c" and newer "e" models.

The generally preferred machine designations are:
Apple ][ or Apple II for pre-][+ models
Apple ][+ or Apple II+
Apple IIe for non-enhanced IIe computers
Apple //e for 128k-enhanced IIe computers
Apple //c
Apple IIc+
Apple IIgs or GS or best (if you have the fonts) ||GS

The Apple //c is the compact (the "c" means compact) version of the Apple IIe. It has the same characteristics but lot of features which are optional on the IIe are provided on the //c (floppy disk drive, 80 columns display, color display, 128 KB RAM), but unlike the Apple IIe, it has no expansion slots, so it is hard to add features to this computer. It runs either with DOS 3.3 either with ProDos and has the first version of QuickDraw in ROM.

The Apple //c was originally designed to be a portable version of the Apple II, but it wasn't a stand alone system, it has no batteries and no LCD screen (Apple would soon release the items), it could also be used with a small 9" monochrome green screen which plugged into the unit. The Apple //c was mainly used as a desktop computer and was replaced with the Apple IIc+ in 1988.

The Apple IIc+ unit was a direct response to the Laser 128EX/2. Apple retrofitted the //c design to try to compete with Video Technology's high speed Apple II clone. The retrofitting is evident in the design of the motherboard. The motherboard runs at 1Mhz, unlike the Laser 128EX/2. In order to run its programs faster, Apple used a 4Mhz 65C02 with 8k of high speed SRAM cache and licensed the accelerator design from Zip Technologies (makers of the ZipChip accelerator for the IIe and //c). They built an accelerator into a 1Mhz motherboard rather than design a faster motherboard from scratch.

The designers of the Apple IIc+ originally wanted to make a portable ||GS. Apple's management, bent on promoting the Mac, balked at the idea. At the same time, the Laser 128EX/2 made a quick design cycle mandatory. The result is an updated //c. Apple //c went under several revisions: you can discover which machine you are using issuing the command PRINT PEEK(64447).

If 255 is displayed, you have the first, original model. This model is known to have problems
producing accurate baud rates for serial communications.
If 0 is displayed, you can use 3.5" drives, but you don't have the memory expansion connector.
If 3 is displayed, you have the memory exapnsion connector and you can plug in extra memory.
If 4 is displayed, you have the latest model with memory expansion connector and extra upgrades.
If 5 is displayed, you have an Apple IIc+.

The Apple IIc+ was the finest Apple 8-bit computer ever built, but lack of marketing, the apparent de-evolution in technology compared to the 16-bit Apple ||GS, and the aggressive sale of the Laser 128EX/2 made the IIc+ the most short lived of the Apple II models.