os0511C.bin

octet-stream - 127.61 kB - 05/11/2025 at 20:27

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os0511B..bin

octet-stream - 127.61 kB - 05/11/2025 at 20:01

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os0511A.bin

octet-stream - 127.61 kB - 05/11/2025 at 19:11

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ucode0511A

ucode0511a - 896.01 kB - 05/11/2025 at 19:06

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os0504T.bin

octet-stream - 127.61 kB - 05/04/2025 at 17:34

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loadsym.hex

hex - 18.84 kB - 05/03/2025 at 13:55

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os250503.bin

octet-stream - 127.61 kB - 05/03/2025 at 09:06

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loadsym250313A.z80

z80 - 120.48 kB - 05/01/2025 at 18:18

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loadsym250313.z80

z80 - 0 bytes - 05/01/2025 at 18:17

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ucode250501

ucode250501 - 896.01 kB - 05/01/2025 at 09:01

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ucode250430A

ucode250430a - 896.01 kB - 04/30/2025 at 20:35

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os250430.bin

octet-stream - 127.61 kB - 04/30/2025 at 20:09

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ucode250430

ucode250430 - 896.01 kB - 04/30/2025 at 17:55

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osload.zip

x-zip-compressed - 2.05 kB - 04/14/2025 at 19:24

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Isetta programming manual 250312.txt

plain - 21.83 kB - 03/12/2025 at 12:04

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bin2hex_v2.py3

py3 - 6.84 kB - 01/26/2025 at 11:45

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boot 241221A.z80

Today's stable operating system version. Source code.
Will automatically get loaded after reset.

z80 - 114.23 kB - 12/21/2024 at 13:37

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boot.bin

octet-stream - 17.87 kB - 12/08/2024 at 17:51

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loader 241206A.z80

z80 - 105.98 kB - 12/06/2024 at 21:43

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loader 241206.bin

octet-stream - 6.36 kB - 12/06/2024 at 21:37

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apple1.woz

Executable for Isetta. It switches from Z80 to 6502 instructions and runs the original Apple 1 BASIC.

woz - 9.66 kB - 07/11/2024 at 20:54

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tge bin 240622A.txt

The Great Escape, Isetta executable for this ZX Spectrum game.

plain - 135.01 kB - 06/22/2024 at 07:11

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mm.z80

Manic Miner, original source code for this ZX Spectrum game.

z80 - 345.95 kB - 06/09/2024 at 09:47

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altair8.bin

The original Microsoft 4k Altair BASIC, with small changes in I/O to run on Isetta.

octet-stream - 8.99 kB - 06/02/2024 at 19:39

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isetta-bu12-240531.py3

py3 - 48.82 kB - 06/01/2024 at 20:06

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loader 240526.bin

This is included in the microcode. The microcode will copy this to main RAM and start executing. The loader fetches "boot.bin" from serial flash and executes it. The loader can also fetch a file from the Raspberry Pi and start executing it. It has a few more functions.

octet-stream - 5.96 kB - 05/26/2024 at 16:39

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Isetta Z80 instruction cycles.pdf

Number of cycles for each instruction, compared to the number of the classic Z80

application/pdf - 108.86 kB - 05/03/2024 at 09:49

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Isetta 6502 instruction cycles.pdf

Number of cycles for each instruction, compared to the number of the classic 6502

Adobe Portable Document Format - 91.32 kB - 05/03/2024 at 09:48

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generated microcode 240419.txt

Readable microcode for 6502, Z80, Isetta reset and device drivers.

plain - 347.98 kB - 04/20/2024 at 09:52

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isetta milestone 240419

Raspberry Pi Python3 program, to program the microcode flash chips, and to provide character I/O for Isetta. Milestone 240419 is the first time Apple basic runs on Isetta hardware (using RPi for character I/O).

isetta milestone 240419 - 36.50 kB - 04/19/2024 at 17:30

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microcode bin 240419B.txt

Binary (hex format) version of microcode

plain - 896.01 kB - 04/19/2024 at 15:22

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Isetta 20231204.pdf

Schematic (not fully up-to-date)

Adobe Portable Document Format - 3.16 MB - 12/04/2023 at 19:42

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Isetta 20230610.pdf

First version of schematic.

Adobe Portable Document Format - 2.17 MB - 06/11/2023 at 13:31

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microcode 230421_new.txt

First version of 6502 microcode generator.

plain - 39.04 kB - 04/21/2023 at 20:55

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