Questions tagged [apple-ii]
For questions about the Apple II series of personal computers, and related software and hardware. For questions about Apple hardware in general, use the tag "apple"; for questions about the IIgs in particular, use the tag "apple-iigs".
191
questions
1
vote
0answers
69 views
Frozen horizontal width coil in old CRT monitor
I have an old Apple IIe CRT monitor which could use a small horizontal width adjustment. Unfortunately, as I try to rotate the hex key in the coil with a CRT adjustment tool, it doesn't want to move. ...
1
vote
1answer
60 views
How many different standard boot sectors are there for Apple II DOS 3.3?
When formatting a blank 5¼ disk on an 8-bit Apple II using the INIT command, was there only ever one variation of the boot sector code that was written, or was it updated from time to time over the ...
4
votes
1answer
55 views
Determining which sectors in an Apple II floppy disk/image are used when the boot sector declares more than 1 sectors
The Apple II disk bootstrap process looks at the first byte of track zero sector zero to see how many sectors long the bootstrap code will be. It then loads these sectors at location 0x0800 and jumps ...
2
votes
2answers
131 views
How can the composite out of an Apple II be disabled?
The PC Transporter provides composite out via a cable run to the internal video header of the Apple II. In order to do this, I assume it has to disable the sync and colorburst generators so the Apple ...
2
votes
1answer
69 views
Which Apple II emulators were the first ones each to use the .do and .po “dsk” floppy disk image file formats?
Apple II emulation must have started around 25 years ago but I can't seem to find a history of emulation of the platform.
There are several disk image file formats but for now I'm interested in the ...
3
votes
1answer
161 views
What bug in first version of game Karateka for Apple 2e cause this game reset in Apple 2c?
If try start first version of game Karateka for Apple 2e in Apple 2c, Apple 2c will restart after computer read game from disk after few seconds. Later version of Karateka for Apple 2c work. What is ...
2
votes
1answer
286 views
How do I read the position of an Apple II joystick?
Many games on the Apple II supported input from the keyboard, joystick, and Sirius Joyport. While reading the keyboard and Joyport are straightforward, getting the joystick's position is not.
How ...
3
votes
1answer
71 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 ...
7
votes
2answers
760 views
How can I programmatically determine whether an Apple II .dsk disk image is a DOS .do image or a ProDOS .po image?
I'm interested in working with the most common Apple II disk image file format, .dsk.
(I only programmed these machines briefly in Basic around 1979-81 and have not been in the emulator scene, so I'm ...
5
votes
2answers
156 views
How to get out of Apple IIe mode on Macintosh Color Classic?
I just picked-up a Macintosh Color Classic with an Apple IIe card. I've never used one of these before but was able to get it to enter into Apple IIe mode. However, I cannot seem to figure out how to ...
2
votes
1answer
87 views
How was the second bank of Apple IIc ROM accessed?
The original Apple IIc had a 27128 16 KB ROM mapped into the
$C100-$FFFF range (the $C000 page was decoded for I/O). According to
the Apple IIc Technical Reference Manual the ROMEN1*
and ROMEN2* ...
3
votes
2answers
164 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 ...
7
votes
2answers
154 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 ...
3
votes
1answer
118 views
Please Identify this Apple II Diagnostic Message: “IOU FLAG E5: 1 2 3 4 8”
Does anybody know the meaning of this message from the Apple IIe diagnostic?
IOU FLAG E5: 1 2 3 4 8
What are addressing the 1 2 3 4 8?
I’m pretty sure that IOU is the I/O chip, E5 is the location ...
8
votes
1answer
219 views
6502 False Reads and Apple II I/O
The 6502 series of CPUs has an
interesting quirk:
indexed loads and stores may perform a "false read", reading from the
target address or a different address on a previous page. There are
situations, ...
12
votes
1answer
557 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 ...
3
votes
2answers
156 views
Why did the Apple Disk II version 3.3 change the boot protocol?
From what I understand, early versions of the Disk Controller II required that there never be two or more consecutive bit times without a phase transition (which would read as "0") but an upgrade to ...
7
votes
1answer
201 views
Did the Apple II Integer BASIC use SWEET16?
In the Byte magazine article that Woz wrote about the Apple II (Vol 2, No 5), on page 43's last paragraph he mentioned how SWEET16 was useful and he estimated that about 20% of the Integer BASIC code ...
7
votes
2answers
467 views
How do you use the INHIBIT pin on the Apple II bus?
Pin 32 of the Apple II bus is a signal called /INH (short for "INHIBIT"). Some of what I found online about using this pin for an Apple II expansion card suggests it was inconsistently implemented ...
4
votes
0answers
151 views
How can I connect a PIA or VIA chip to the Apple IIc?
I have an early Apple IIc, model A2S4000 with the 342-0272 motherboard
and ROM 255. (I am considering upgrading the ROM, perhaps with a
switch that would let me switch between different ROM versions.)
...
6
votes
2answers
329 views
Are there standalone emulators of Applesoft Basic?
My only retrocomputing desire is to program in Applesoft Basic and relive the Apple II days from the 1980's. Playing games is of no particular interest to me. I just want to use a keyboard, not a ...
6
votes
2answers
191 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),
...
4
votes
1answer
322 views
Price of original Apple ][ in 1980?
Apple introduced the "new and improved" Apple ][ Plus in 1979, but continued to sell the original ][ until early 1981. I speculate that some customers must have chosen the original Apple ][ over the ...
3
votes
3answers
438 views
How to transfer the address of a data block into zero page using the Merlin 8 assembler on my Apple //e?
I've been fooling around with the Merlin 8 (v2.58) assembler on my Apple IIe and ran into a small snag.
Basically, I would like to load the address of a block of data into a two-byte pair in zero ...
3
votes
2answers
155 views
How exactly does the Apple II monitor set and use the “last opened” and “next changable” locations?
Chapter 3 of the Apple II Reference Manual describes the
machine-language Monitor. On page 41 it describes certain
remembered locations:
The Monitor remembers the addresses of up to five locations. ...
11
votes
2answers
419 views
Best learning path for Apple IIe assembly language [closed]
I have an emulator up and running and access to the asimov ftp site, and I want to learn how to program assembly language on the Apple IIe. What assembler should I use (Merlin? LISA?) and what book or ...
5
votes
2answers
417 views
Where did the “LEVI” file selector/runner for the Apple II DOS 3.3 come from?
There's a fairly common BASIC program for DOS 3.3 on the Apple II that clears the screen, prints a catalog of the disk, and allows you to select files by letter to run or do other operations on them. ...
2
votes
2answers
278 views
80s game about running and maintaining a power station
Way back in the late 80s there was a game that centered around maintaining and running a power station for the local town. It wasnt particually complex or graphic.. just fun. On the lhs of the screen ...
15
votes
1answer
2k views
Why did the Apple IIe use a 2 MHz-rated 6502, even though it ran at only 1 MHz?
The Apple IIe was designed to be timing-compatible with the Apple II+ so that timing-depndent software (such games and copy-protection systems) and hardware designed for the Apple II and II+ would, ...
3
votes
1answer
181 views
Is there any RAM disk software available for Apple II DOS 3.3?
I have an Apple IIc with 128 KB of RAM, about half of which goes unused. Since the IIc has only one drive, it would be convenient to use some of that unused RAM as a RAM disk. I know that this is ...
4
votes
1answer
223 views
Is it possible to detect Horizontal Blanking (HBL) on an Apple II
Is there a way to detect HBL and or VBL on an Apple II, and if yes, how it's done?
5
votes
3answers
730 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 ...
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 ...
26
votes
3answers
2k views
What do the '80/40' and 'keyboard' buttons on my Apple IIc do?
Above the keyboard of my Apple IIc there are two buttons that say "80/40" and "Keyboard".
On my machine, they both kinda feel broken. When I press them, they recede into the case and remain there for ...
12
votes
2answers
968 views
How is the Apple II text flash mode timed?
On the Apple II, there are three 40 column text modes: normal (white on black), inverse (black on white) and flash. A text screen can contain a mix of text in all three of these modes.
Flash mode is ...
3
votes
4answers
957 views
Why use an ADC or SBC with immediate zero on a 6502?
I'm perusing the Apple I version of BASIC, later known as Integer BASIC on the II. In several places I see...
ADC #$00
or
SBC #$00
Unless I'm mistaken, these mean add/subtract zero. What ...
9
votes
4answers
3k views
Is it possible to swap the Apple //c's monochrome CRT tube for a color one?
I just love the Snow White industrial design language of the Apple //c, especially when paired with the Monitor //c. It is a classic design that doesn't show its age. I've even recently seen them ...
9
votes
1answer
239 views
How can slot 1 of the Apple ][ replace the keyboard?
Nick Westgate posted a comment a few years back on a question about how slot 7 was unique stating that "Slot 1 on the //e is also unique - it can be used to replace the keyboard".
What was it about ...
2
votes
2answers
198 views
Could Apple II cards be used on any 6502 platform?
Looking over the Apple II expansion card pinout, it seems it's largely just the pins of the 6502 plus some +12V supplies and such.
Generally speaking, though, is there any reason any other 6502 ...
11
votes
2answers
311 views
Can a 1,44MB or 720K PC floppy drive be made to work with an Apple II family?
I am restoring a couple of Apple II machines. I would like to add an external 3.5" floppy drive, but they are prohibitively expensive. I have tons of older PC floppy drives and I wonder if they could ...
7
votes
1answer
327 views
In the 1970s, had there been a way that a home computer using a TV as monitor could get FCC approval for Apple II style slots without cheating?
I’m reading the book “Atari Inc.: Business is Fun” by Curt Vendel and Marty Goldberg. (By the way, it’s a fun read, highly recommended.) It states that when the Atari engineers had been developing the ...
8
votes
2answers
244 views
In an Apple IIc, how is memory beyond 128K addressed?
I always thought than in a memory-expanded Apple IIc fitted with firmware version 3 or 4 and an Apple-built memory expansion, the extra memory above and beyond the first 128K is connected in a way ...
4
votes
2answers
133 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 ...
9
votes
2answers
314 views
Were expansion slots fundamentally incompatible with FCC regulations?
The Apple II provided the ability to connect to your TV (as opposed to purchasing a dedicated monitor). However, at that time, the FCC criterion for applying stringent RF emission limits was 'device ...
2
votes
1answer
269 views
How can I make an external PSU for an Apple IIc?
I purchased an Apple IIc from an auction site, but it came without the
external power supply unit. While this question and its
answers describe how to open up the IIc and use alligator clips to
power ...
1
vote
3answers
355 views
Using Integer Basic on Apple II Plus without a Language Card?
Was it possible to load integer basic and use it without a language card or were the addresses fixed to rom?
EDIT: Sorry, I meant Apple II+ (I had an europlus) so I wrongly put IIe.
7
votes
1answer
255 views
Importance of obeying Apple II IRQ priority
In the Apple II, DMA and IRQ priority is determined by a daisy-chain system, in which a card may only assert an IRQ or perform DMA when all higher-priority cards allow it.
I understand the importance ...
3
votes
2answers
195 views
What is the name/type of the Apple IIc case screws?
My Apple IIc is what appears to be the first US model: A2S4000 with
version 255 ROMs. The upper half of the case is held to the base with
six Phillips drive button-head 2 cm screws with a very wide ...
8
votes
0answers
253 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
...
2
votes
1answer
210 views
What are the differences between the various HxC Floppy Emulator hardware options when used with an Apple II?
I have an Apple IIc for which I would like an FDD emulator and I am
considering buying an HxC Floppy Emulator to use with it. The Slim
model does work with the Apple II, as demonstrated in this
video.
...
