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.

Filter by
Sorted by
Tagged with
22
votes
3answers
2k views

What makes slot 7 of the Apple ][ unique from 1-6 and how was this used?

In the Apple II, there are three unique slots (depending on model): Slot 0 (on the ][ / ][+) which is typically used for language cards. "Aux" slots in the //e and IIgs, typically used for memory ...
30
votes
5answers
3k views

Does every retrocomputer and console with NTSC composite output have 'artifact color' ability?

Artifact color is heavily associated with the Apple ][, since that is the only method the machine had to produce a color display. I was looking at the fantastic demo for IBM PC + CGA, 8088MPH, and I ...
36
votes
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,...
21
votes
2answers
802 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, ...
9
votes
1answer
979 views

Apple II bus: IRQ and DMA priority

One of the weirdest misfeatures of the Apple II - and perhaps the dumbest thing Woz ever designed - is the vestigial priority system for IRQ and DMA on the Apple II expansion bus. Each slot has four ...
23
votes
5answers
4k views

Over its lifetime, how many Apple II computers were sold?

It would be nice to break it down by model if possible.
16
votes
3answers
1k views

What are the differences between the versions of AppleSoft BASIC?

Apple did make some changes to AppleSoft BASIC over the years between the first version on the Apple II and the last version on the Enhanced IIe and IIe card. What are the differences between the ...
3
votes
1answer
114 views

Converting Apple II ProDOS blocks to DOS tracks and sectors

The 8-bit Apple II had two disk operating systems with different disk access semantics. DOS used tracks and sectors. A sector is 256 bytes. ProDOS used blocks. A block is 512 bytes. But mapping ...
18
votes
5answers
3k views

Can a retro-computer be a useful way to learn computer-architecture fundamentals?

I've been reading about the fundamentals of computer architecture, but I think I could get a better grasp of the basics if I could could have an actual device to play with. I had considered building ...
27
votes
2answers
3k views

Apple II: Applesoft BASIC memory management

I am trying to write an Applesoft / floating point BASIC program using high resolution graphics and some assembly language code. My BASIC program is quite large, and after running the program for a ...
23
votes
4answers
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 ...
27
votes
17answers
6k 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 ...
29
votes
4answers
1k 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 / ...
40
votes
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 ...
24
votes
2answers
3k views

Why did the original Apple //e have two sets of inverse video characters?

According to Apple II Technical notes Mouse #6, updated January 1989, In unenhanced Apple IIe computers, the alternate character set contained two sets of inverse uppercase characters. In the ...
16
votes
1answer
2k views

How do accelerators and CPU cards work on the Apple II?

An Amiga 1200 exposes the entire CPU bus on the expansion port, so that an accelerator only needs to assert BR which causes the onboard CPU to stop all computation and electrically disconnect from the ...
14
votes
1answer
1k views

What was the change to the Apple //e motherboard that allowed for Double HiRes graphics?

Double Hi-Res graphics (DHGR) was a nice addition to the Apple ][ line as it allowed for higher resolution 560x192 graphics with 16 colors in comparison to the traditional 280x192 with 6 colors. It ...
13
votes
1answer
582 views

Odd tokenizing in Integer BASIC

While researching the underpinnings of Integer BASIC (IB), I came across an oddity I'm hoping someone can explain. Unlike MS-derived systems, IB converted numeric constants to their 16-bit ...
13
votes
3answers
909 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 ...
13
votes
2answers
730 views

How to connect an Apple IIe to an external Sider hard disk drive

I am a sucker for 8 bit junk components, and recently picked up a Sider hard disk for my Apple //e. I was able to talk myself into the purchase by fondly remembering how I lusted after this piece of ...
12
votes
1answer
453 views

How did the Lazer Systems Graphics Plus board work?

The first two Apple II models (the ][ and ][+) were unable to display lower case on the text screen. Some 3rd parties made lower-case adapters that replaced the character ROM (e.g. Dan Paymar's ...
12
votes
1answer
2k views

On what Apple II and II+ keyboards can the ']' character be generated?

It had long been my impression that while brackets [ and ] could be displayed by the Apple II, the standard Apple II keyboard was not capable of generating them. Some time ago I noticed that on this ...
12
votes
2answers
993 views

How was Prince of Persia “better/faster” with RWTS18?

I was reading about Prince of Persia over at POP Code Review. In that article, the writer printed an interview with Roland Gustafsson, the inventor of RWTS18 copy protection for the Apple II series. ...
10
votes
1answer
420 views

Apple II SCSI: Maximum drive / partition size?

Using an "SCA to 50-pin adapter", it is possible to use a 300 gig Ultra-320 SCSI drive from 2004, with an Apple II outfitted with the Apple SCSI controller. It seems possible for the electronics to ...
8
votes
2answers
493 views

What's the best way to hook up an external power supply to the Apple IIc without a 7-pin female DIN plug?

As seems to be typical with Apple IIc purchases these days, mine came without the external power supply. I have ordered some 7-pin female DIN plugs and other adapters that will let me plug a modern ...
7
votes
2answers
632 views

How could a 16-sector PROM Apple II access a 13-sector disk?

When the Disk ][ first came out for the Apple II, the PROMs on the interface card only knew how to work with a 13-sector format. Around 1980, the Disk ][ was updated with 16-sector PROMs either for ...
6
votes
2answers
235 views

Why does _Beneath Apple DOS_ show FM encoding rather than GCR?

From the beginning in 1978 the Apple II floppy disk system used GCR encoding to convert data bytes to sequences of binary values to be written to the diskette: first 4-and-4 encoding (never released), ...
18
votes
3answers
1k views

Did the Apple IIe Platinum include all feature enhancements from the Apple II line?

Not including the Apple IIgs, did the Apple IIe Platinum include all enhancements made by Apple? For example, the first Apple IIe couldn't utilize the Double Hi-Res mode from what I understand. In ...
10
votes
2answers
677 views

How did the Microprofessor II have space for a Chinese font in the ROM?

There's an Apple II clone from Taiwan which apparently forgoes the text mode and just has a graphics mode because it's simpler that way to render Chinese writing. It had a 16K ROM, of which 12K is a ...
9
votes
1answer
555 views

How can I tell if an Apple II disk image is bootable?

I have around 500 floppy disk images from an Apple II and IIgs BBS/usergroup that closed down recently. Some of the disks are bootable, but many aren't. Is there an easy way to tell if a disk boots ...
9
votes
2answers
239 views

Apple II: ProDOS partitions on floppy disks?

On the Apple II using ProDOS, was it possible to create partitions on a floppy disk? Would it be possible to have two or more partitions on a 140k 5.25" or 800k 3.5" disk? (The question here is not ...
8
votes
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 ...
8
votes
3answers
454 views

Origin of dealer networks

Roughly speaking, the two main ways to sell computers are, and particularly were in the old days, Three digit price tag sold to individuals => mass market, department stores and suchlike. Four digit ...
6
votes
2answers
467 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 ...
6
votes
3answers
791 views

How does the Apple II read lines for video display from the text-mode frame buffer?

(This question applies also to the low-resolution graphics video buffer, since that uses the same frame buffer as text mode, just displaying it differently.) As described on page 1-12 et seq. of The ...
5
votes
2answers
294 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 ...
4
votes
2answers
201 views

Apple IIe auxiliary RAM bank select register address — C073 or C07X?

On the Apple IIe system, an "auxiliary RAM" card may be present which expands the built-in 64 kB RAM. When using an aux RAM card which has more than 64 kB, the auxiliary RAM bank in use can be ...
4
votes
2answers
530 views

How to get into Apple BASIC prompt on an Apple IIc?

I just picked up a used Apple IIc. For some reason all I get when I boot is Check Disk Drive on the screen, even with a bootable disk in the internal drive: I cannot even get the system to read the ...
4
votes
0answers
479 views

What's the first use of the term, “1977 Trinity”?

The term "1977 trinity" has been used, here on Retrocomputing SE and elsewhere, to refer to a set of three computers that started shipping in mid- to late-1977: the Apple II, the TRS-80 ...
2
votes
1answer
114 views

What are the screen editor commands for MIT LOGO for the Apple II?

I'm playing with MIT LOGO for the Apple II (1981). When I type TO GREET :NAME and hit ENTER it drops me into the "MIT LOGO screen editor." What are the commands I can use here to edit, save, etc.?