Questions tagged [apple-ii]

The Apple II series of personal computers and related software and hardware. Use [apple-iigs] for the Apple IIgs in particular, or [apple] for Apple hardware in general.

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5
votes
1answer
431 views

Copy content between floppy disks on Apple II

I own an Apple IIe with the Apple DuoDisk device. I've been trying to find out if it is possible to copy content from a floppy disk inserted into the disk 1 slot into a floppy inserted on the disk 2 ...
0
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1answer
120 views

How are Apple II address lines mapped to DRAM rows and columns?

The Apple II's MK4096 (4 Kbit) and MK4116 (16 Kbit) DRAM chips have 6 and 7 (respectively) address line inputs that are multiplexed: first the row address bits and then the column address bits are ...
4
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1answer
143 views

Does the Apple II's non-linear frame buffer layout help DRAM refresh?

The Apple II uses non-linear frame buffers for text and graphics. Rather than storing each line in sequence at lines 0-23: $400, $428, $450, $480,¹ ..., $7D0 it stores them at lines 0- 7: $400, $...
26
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3answers
5k views

What is DRAM refresh and why is the weird Apple II video memory layout affected by it?

I've roughly known the concept for years, but never really understood it. Back in the day, two types of RAM typically used in home computers: static and dynamic RAM. Static RAM (SRAM) was apparently ...
6
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3answers
315 views

How did Apple IIe software handle 64K bank switching?

The early microcomputers were well served by 8-bit CPUs with 16-bit address bus width, but later generations of these machines tended to run out of address space, and had to resort to some form of ...
7
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2answers
1k views

Arcade games in Apple IIc's ROM

Is there a website where I can find the old games that where pre-installed in the Apple IIc ROM? When I could not get an OS disk, I could still have some fun with my Apple IIc by playing those arcade ...
40
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4answers
8k views

What determines the color of every 8th pixel on the Apple II?

On the Apple II there's an interesting way to add a little color to the bitmap, since the high bit select the palette used for the three-and-a-half pixels represented by the byte. Like this: 0: Black,...
5
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1answer
329 views

Apple II Assembly DSECT

I'm trying to define a section of data in a program. The Apple 6502 Assembler/Editor mentions an assembler directive called "DSECT" but I can't tell if I'm using it correctly or not. Here is ...
6
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4answers
907 views

How to use HGR2 (or HGR) on an Apple II

I am a big fan of the TV show lost, and I was trying to make the Dharma Initiative logo. But at certain point I couldn't add new lines of code and the final part of the logo was cut off. I tried to ...
7
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2answers
207 views

How did Apple IIc daughtercard expansions work?

I've been doing a lot of reading about the ways Apple IIc owners expanded their machines in the absence of the IIe's slots, and it's very intriguing stuff. The ones that I'm most curious about are the ...
12
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2answers
908 views

How do I clean/refurbish an Apple IIc Keyboard?

My Apple IIc is what appears to be the first US model: A2S4000 with version 255 ROMs. The keyboard PCB is marked 820 0108 03 ©1983, and the keyswitches are the "cross" type as seen below, without any ...
22
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2answers
976 views

How do I use shadowed memory to render Super Hi-Res quickly?

The Apple IIgs video memory is controlled by the 1MHz Mega II chip, so directly accessing the Super Hi-Res page in bank $E1 is slower than accessing other memory. How can I render in "fast" memory, ...
7
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1answer
271 views

Looking for educational AI game for classic Mac OS

I'm looking to find the name of a (purportedly) educational Mac game I purchased from a book fair handout around 1990–91. The concept was that you would make up the rules to your own board game on a ...
14
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4answers
1k views

Did Apple bundle a specific monitor with the Apple II+ for schools?

Sometime in 1980 (or maybe 1981) my school district purchased its first batch of Apple II+ computers. I remember vividly they had absolutely no idea what to do with them, and so the machines were ...
6
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1answer
163 views

What determines the amount of space occupied by an Applesoft BASIC program?

I've been writing an Applesoft BASIC program over the last few months or so (IIgs and IIe, ProDOS 2.4.2 with BASIC.SYSTEM v1.6). My large BASIC program was sitting at something like 51 ProDOS blocks. ...
6
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1answer
323 views

Why does Applesoft get confused by a nonzero value at $0800?

Applesoft programs start at location $0801 in memory (usually). If you put a nonzero value at address $0800, though, you get an error when you try to run the program: ?SYNTAX ERROR IN 65124 Why does ...
17
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3answers
949 views

Apple II: DOS 3.3 Virus?

Does anyone know the source of this Apple II DOS 3.3 virus that infected my disks back in the 1990's? I got it from a public domain disk collection that was given to me by a friend, called the ...
8
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4answers
340 views

Applesoft (pseudo) Random Numbers - alternatives?

What are the alternatives (with examples on how to implement) to Applesoft RND(1) command? I have read of people using a completely different algorithm by poking machine code stored in a DATA ...
7
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2answers
892 views

How long should I expect the Apple IIc self test to run?

I purchased a vintage Apple IIc computer and I want to make sure there are no failing components. I booted up the computer while pressing both Apple keys (open and close) at the same time. The ...
6
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3answers
719 views

Apple II Toggles between 40 and 80 columns in assembly language (Apple IIc)

To switch from 80-column to 40-column display, what is the difference between the following two actions: lda #$11 jsr COUT ; $FDED and sta $C00C ; 80coloff switch In the first case, I do not ...
5
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3answers
250 views

Apple II: ProDOS, zero length prefix and MLI calls

I have a simple program on my Apple IIc written in assembly language. It starts by getting a filename from the user (just the file name, not the full path), then it opens the corresponding file with a ...
21
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5answers
1k views

How were binary subroutines embedded in Integer BASIC programs?

Programs written in Apple's Integer BASIC sometimes had bits of machine code embedded in them. This was more convenient than loading the code separately, especially when the program was loaded from ...
4
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1answer
230 views

Apple IIc : displaying HGR page 1 in AUX memory

I need to display HGR page 1 ($2000 to $3FFF) located in AUX memory (not in MAIN memory). According to the "Apple IIc Reference Manual - Volume 1", page 45, I must first turn 80Store on by ...
11
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2answers
1k views

Trying to identify an Apple II space trading game

I'm trying to identify a game I remember from my first exposure to computers (the Apple II at secondary school back in the late '70s). I remember two games I really enjoyed, the first a Star-Trek-...
4
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2answers
382 views

Was the ProDOS beep part of the kernel or just a commonly duplicated piece of code?

On the Apple II, system beeps were typically just the 'Control-G' beep noise. However, many ProDOS-based applications from Apple Computer abandoned the firmware-based beep routine and instead used a ...
11
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1answer
1k views

Testing/using a joystick in AppleSoft?

How does one use joysticks in a program on the Apple //? I have three different joysticks here and I would like to visualize their state (pot and button values), maybe similar to the SDL joystick ...
2
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1answer
189 views

How to convert series of hex digits in memory into the format for use with Applesoft math subroutines

I'm trying to write a calculator program in assembly for the Apple //e. I know that there are built-in subroutines for performing all kinds of math operations involving the floating-point accumulator (...
2
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1answer
193 views

Apple II double buffering and double high resolution

I write programs in assembly language using HGR mode. For a fluid display, I use the double buffering technique. Is it possible to use this technique in DHGR (double high resolution)? If so, I am ...
19
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2answers
1k views

How did the Apple IIGS automatically slow 5.25 inch disk I/O code for backwards compatability?

Apple II software often used hard-coded timing for 5.25 inch floppy disk I/O, for example to control the duration of each track step or the rate at which bytes are written and read from the disk. ...
29
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4answers
2k views

Absolute maximum number of nibbles on an Apple II floppy disk track?

The Apple 2's disk drive controller and 5¼" floppy disks have the following metrics: The disks is spun at (roughly) 300 RPM (Revolutions per Minute), which means it takes = 1000 ms/sec / (300 RPM / ...
5
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1answer
333 views

Apple I and II video output to a contemporary TV set?

Is it possible to connect the unmodified video output from an Apple 1 and Apple II (with their non-standard/out-of-spec NTSC sync pulse levels and/or timings) to a (currently in-production and ...
6
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3answers
2k views

How does the Apple II address more than 128KB of RAM?

For the Apple //e, it was very common to have an extended 80-column card installed which brought the machine up to 128KB of RAM via 2 banks of 64KB each. There are soft switches in the $C0xx space ...
6
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2answers
497 views

Identifying the functionality of the memory select IC in Apple II

Three are ICs labeled memory select used in Apple II. One to apply A6 on the three banks of RAM ICs. One to generate /RAM_SEL applying the latched RAM output to the data bus. And one to apply /CAS on ...
5
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2answers
611 views

What is the reason of the particular range of the last 4K block of memory selection in Apple II

Following my previous question on Identifying the functionality of the memory select in Apple II and now that I know that the memory select device is simply an interconnection block. Searching for ...
8
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2answers
2k views

Build a hardware clone or emulator of Apple II?

These days we are constantly seeing low-cost boards that have huge power (raspberry pi, various arduino-like microcontrollers.) I am hoping I could make, or get, a clone or emulation of an Apple II ...
3
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1answer
269 views

What bug in first version of game Karateka for Apple 2e cause this game reset in Apple 2c?

If I try to start the first version of the game Karateka for Apple IIe on an Apple IIc, the Apple IIc will restart after reading the game from disk after a few seconds. Later versions of Karateka for ...
3
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0answers
360 views

How do Apple II BASIC compilers compare? [closed]

Programs like The Beagle Compiler allow AppleSoft BASIC or other Apple II BASIC variants to be compiled. How do the compilers compare in terms of compatibility with AppleSoft language features? Eg how ...
3
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2answers
251 views

Did any 5.25" floppy drives not based on the Apple Disk II offer quarter-track control

Unlike many drives, the Apple Disk II has inputs that control the individual head stepper coils. These are commonly described as advancing by half-tracks, since advancing a full track requires ...
27
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17answers
7k views

How much did the first hard drives for PCs cost?

I would like to know how much early PC hard drives cost but have only been aable to find adjacent or unsourced data. According to the Centre for Computing History: The "IBM 5161 Expansion ...
2
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0answers
111 views

Apple II DMA daisy chain also used to arbitrate /INH?

On the Apple II series of computers, peripheral cards contend for bus mastership through a priority daisy-chain system. A peripheral card is only allowed to perform DMA if its DMA_IN line is at logic ...
13
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3answers
958 views

Anyone remember how to write the Apple ][ HIRES pages to disk to make screenshots?

The Apple ][e had 2 HiRES video pages, HiRES animation involved switching between the 2 pages and redrawing the screen. A really early way to take an in game screenshot was to dump the computer with ...
8
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1answer
1k views

Why does the Applesoft BASIC have shapes?

Why did Apple include shapes in Applesoft BASIC? There are no sprites on the Apple II, but shapes provide a simple vector drawing tool. As graphics go the shapes are kind of an odd duck, they provide ...
5
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2answers
369 views

What were the alternative graphic cards for the Apple II?

In this question, it's mentioned the Apple II's slot 7 was used by third party graphics cards. Is there any documentation on those? What were those cards and what were their capabilities?
13
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1answer
906 views

Why didn't Apple II / II+ 80-column cards use slot 7?

Based on a previous question about how slot 7 on the II / II+ was unique as it had two video signals on it that other slots lacked, I am curious why the slot wasn't taken more advantage of. But that ...
5
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2answers
356 views

How to test an Orange Micro Grappler+ card?

Are there some tests that can be done to verify the operation of an Orange Micro Grappler+ printer interface card (1982) in an Apple IIe? I've searched around the web and the paper manuals for ...
10
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4answers
3k views

Is it possible to swap the Apple IIc's monochrome CRT tube for a color one?

I just love the Snow White industrial design language of the Apple IIc, especially when paired with the Monitor IIc. It is a classic design that doesn't show its age. I've even recently seen them ...
40
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3answers
4k views

How did Apple II BASIC programs protect against listing?

I seem to recall from my high-school days that certain Apple II programs protected themselves from being listed and therefore modified. If you tried to do it, the machine would simply reboot. How did ...
2
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1answer
188 views

How did VisiCalc decide how many decimal places to display?

VisiCalc represented numbers in BCD to be able to handle decimals precisely. But how did it decide how many decimal places to display? In some screenshots like https://www.researchgate.net/figure/A-...
10
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3answers
2k views

Algorithm for Apple IIe and Apple IIgs boot/start beep

What is algorithms use for boot/start sound (when turn on computer) in Apple IIe and Apple IIgs? I can't find information about Apple boot sound algorithms or where in computer ROM store either ...
5
votes
1answer
133 views

What are the HIFI and MUSIC modes of the RocketChip?

One of the CPU accelerators for the Apple II series is the RocketChip, which came in 5MHz and 10MHz versions. It came with a floppy disk that contained a number of utilities for manipulating the ...

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