Browse this growing collection of Apple-1 programs.
A tribute to history and their hackers.
Run them in the emulator right away, or just on the real machine.
version
Browse this growing collection of Apple-1 programs.
A tribute to history and their hackers.
Run them in the emulator right away, or just on the real machine.
by Mike Willegal in 2021
Runs different RAM tests in endless passes until stopped by a reset.
I wrote this basic memory test in order to help kit builders test their boards. The original source code was taken from the 6502 memory test from this compute magazine article.
Written by Mike Willegal on his personal website.
The range of memory has to be set before starting the program with 280R.
Using the monitor, enter the starting address and ending address + 1 into locations
0-3of memory. Example: To test memory fromE000toEFFFenter the following into the monitor:
0: 00 E0 00 F0
The above will normally test the lower bank ICs at W0 - W7, depending on the jumper wire setting on the Apple-1 main board (W-E).
To test the upper bank at X0 - X7 (memory address 0000 - 0FFF, with default jumper wire X-0) take into account the program uses a couple of the first bytes and 0280 - 03A1.
The following ranges can be tested:
| Memory Bank | Address range | Set with Wozmon |
|---|---|---|
| △ Upper X0-X7 | 0009 - 027F 1 |
0: 09 00 80 02 |
| △ Upper X0-X7 | 03A2 - 0FFF |
0: A2 03 00 10 |
| ▽ Lower W0-W7 | 1000 - 1FFF |
0: 00 10 00 20 |
| ▽ Lower W0-W7 | E000 - EFFF |
0: 00 E0 00 F0 |
1 This includes the zero page and the stack. Please note that the Apple-1 will hardly boot if it has memory issues here. Memory ICs can be swapped between the banks to solve this.
After each pass of the test,
PASS XXis displayed on the terminal and the test will start over. Press RESET to stop the test. The test will stop and drop into the monitor if it detects an error.
Test no. Address Expected Actual 01 E000FFDFHere is an example where bit 5 of location
E000was written as a 1 but read as a 0 in the all ones test.
Each pass of a test consists of 6 basic tests.
Number Description 0 All zeros - each byte of memory is verified that a 0x00 value can be written and read 1 All ones - each byte of memory is verified that a 0xff value can be written and read 2 Floating ones - eight passes, starting with 0x01 and moving the 1 bit to left each succeeding pass - 0x02 0x04 0x08 0x10 0x20 0x40 0x80 3 Floating zeros - eight passes, starting with 0x7f and shifting the 0 bit to the right each succeeding pass - 0xBF 0xDF 0xEF 0xF7 0xFB 0xFD 0xFE 4 Address in Address 1 - one pass with low eight bits of the locations address is written to that location - if this fails, you have a problem with one of the low eight address lines (this is pretty unlikely to fail, since you need these address lines in order to load and run this program) 5 Address in Address 2 - one pass with high eight bits of the locations address written to that location - if this fails, you have a problem with one of the eight high address lines
Use your keyboard to interact with this Apple-1 program.
Emulated with HoneyCrisp v1.2.7,
check here for more details.
This website has full functionality (i.e. direct serial transfer and emulation of an Apple-1) when displayed on a larger screen.
In 1976, the Apple-1 Computer was advertised for $666.66 and came with 4K of on-board memory. For a $120 extra, this doubled to 8K of RAM. The provided Operation Manual included the circuit diagram and assembly source code of Wozmon, the operating system.
The Apple Cassette Interface (or ACI) was used to load and save programs from cassette tape. The ACI Manual showed how to install it (the main board had to be jumpered correctly) and explained how it had to be used. Priced at $75, it included a cassette of Apple BASIC.
Woz wrote a BASIC interpreter by himself. It was tiny enough to fit in 4K of memory, but did not support floating point arithmetic. The software itself was free. The Preliminary Apple BASIC Users Manual explained how to write your own games and programs with it.
Cassette tapes could be bought as an original accessory to your new Apple-1. A total of nine programs were available and listed $5 each. Pick one below and go back in time.
At the time, people were also inspired by publications like 101 BASIC Computer Games. They spent their evenings and nights to key-in the games, but soon were disappointed to discover that some of these did not work at all because of the missing floating points... Arghh.
Dive deeper? Read more here and here.
The Apple-1 has a 16-bit address bus and 64kB of addressable space. Within this space the 6502-processor can use the different parts of the computer:
Woz designed a jumper area on the Apple-1 mainboard where the hobbyist-user could configure how memory should be organized. This was very flexible and made extension of the Apple-1 possible.
The full 64kB is split into 16 equal banks of 4kB each by this jumper area. The banks range from 0 to F, hexadecimal. A bank can be tied to one part of the computer: e.g. the ROM, upper RAM chips or a board in the expansion slot.
The default configuration is shown above. For example bank E (address space $E000-$EFFF) was usually tied to the eight lower RAM chips on the Apple-1 mainboard, indicated by W and the black wire in the figure. Usually BASIC was loaded here.
No windows yet. It was called a monitor program back then, the predecessor of an operating system. It allowed reading and modifying the computer's memory and starting programs. Woz his monitor was stored in only 256 bytes of ROM.
To load it, the user had to press RESET after powering on the computer. A back slash \ appeared on the screen with a flashing @ below, the cursor. Indicating the Apple-1 was ready for commands.
Try Wozmon yourself by pressing the
Run button and after that
Reset in the above emulator (any program). Then type 280 RETURN to read a memory location. Values are hexadecimal, so range from 0 to F. Change memory with 280: AB RETURN. Read it again and wow you changed memory!
Follow this excellent course to learn more. The original manual explains Wozmon as well (in Section II) and lists the assembly source code.
Use the 8BitFlux.com Keyboard Serial Terminal to connect to an Apple-1 with this website. It uses the Web Serial API locally and is supported by Chrome and Edge browsers. The Wozmon code of any program can be transferred right away.
Use the Serial button to transfer the current program to an Apple-1. For example, BASIC takes around 20 seconds to transfer, at a speed of 57.6 kbps. The board is compatible with the high-speed TurboType™ format. It also performs a CRC check and has an error LED indicator.
Done transferring the game or program? Switch the input to the attached Apple-1 keyboard by pressing a button and enjoy it. This makes a great kit for hobbyists, museums or public events. More info »
It is easy to run the software with one of these emulators as well:
This website uses the HoneyCrisp emulator. More information can be found here. It has its own software library with even more programs to explore.
View a comparison of emulators here.
An initiative of 8BitFlux.com. This website can be put to full use with a Keyboard Serial Terminal adapter board, which enables you run software on a (real) Apple-1 right away.
The textual descriptions and screenshots of the programs listed on this website are licensed under CC BY 4.0
A lot of recognition goes out to Landon J. Smith for being so kind to share his HoneyCrisp Emulator (also available on GitHub) for use on this website. Many Thanks to Uncle Bernie for his support and provision of his TurboType™ algorithm, which is part of his Apple-1 Toolchain. Last but not least, all this was not possible by all the authors of Apple-1 software and other emulators. The hobby computer enthusiasts of the past, but also people of the present, who keep this hobby so alive. Thank you all.
This website is not associated with Apple Inc. in any way.
It tries to be a tribute to (their) history. It wants to list only software that is already considered to be in the public domain, or its license permits further publication. The (online) sources of the program and other references are listed when known.
No AI is used to describe the software packages here. Human mistakes happen, so please report any nonconformities.
Made behind an 🍎 in The Netherlands.