Editing Apple I (section)

==Hardware==
{{multiple image|perrow = 2|total_width=300
| image1 = Apple 1 mfk bern.jpeg
| image2 = Original 1976 Apple 1 Computer In A Briefcase.JPG
| image3 = Apple I Computer.jpg
| image4 = Museum-Enter-Apple-1-6094652.jpg
| footer = A variety of Apple I cases supplied by customers. The Apple I did not include a stock case, so customers had to supply their own.
}}
The Apple I used a [[MOS Technology 6502]] microprocessor running at {{val|1.022727|ul=MHz}}, and its design was based largely on Wozniak's previous work centered around a [[Motorola 6800]].<ref>{{cite news|url=https://www.cnet.com/news/apple-1-the-machine-that-made-computing-history/|title=10 facts about the Apple-1, the machine that made computing history|first=Michelle|last=Starr|date=June 29, 2016|accessdate=February 9, 2022|publisher=cNet|archive-date=February 9, 2022|archive-url=https://web.archive.org/web/20220209214024/https://www.cnet.com/news/apple-1-the-machine-that-made-computing-history/|url-status=live}}</ref> The unconventional clock speed was chosen to be a fraction ({{frac|2|7}}) of the [[NTSC]] color carrier, which simplified video circuitry. {{val|4|u=KB}} of memory was included on the base machine, which was expandable to {{val|8|u=KB}} on-board and up to {{val|64|u=KB}} by using an add-on card. On-board memory utilized newly available 4Kbit [[Dynamic random-access memory|DRAM]] chips, and was designed to be upgradeable to the next generation of 16Kbit chips for a maximum of {{val|32|u=KB}} on-board memory.<ref name="byte ad">[https://upload.wikimedia.org/wikipedia/commons/4/48/Apple_1_Advertisement_Oct_1976.jpg Apple I advertisement Oct 1978]</ref> An optional $75 plug-in cassette interface card allowed users to store programs on ordinary audio [[cassette tape]]s. A [[BASIC interpreter]], originally written by Wozniak, was provided with the cassette interface that let users easily write programs and play simple games. An onboard AC power supply was included.

The Apple I did not come with a case. It could be used bare, although some users chose to build custom (typically wooden) enclosures.<ref>{{cite web |title=The Apple 1 Case |url=https://www.thegeekpub.com/275777/apple-1-case/ |website=The Geek Pub |date=September 16, 2021 |access-date=September 18, 2021 |archive-date=September 18, 2021 |archive-url=https://web.archive.org/web/20210918175500/https://www.thegeekpub.com/275777/apple-1-case/ |url-status=live }}</ref>

=== Memory map ===
{| class="wikitable"
|+
!Address
!Size 
!Description
!
|-
|0x0000 - 0x0023
|36 Bytes
|RAM
| rowspan="6" |4K systems
(minimal system, cannot load [[Integer BASIC|wozbasic]]))
|-
|0x0024 - 0x002B
|8 Bytes
|[[Machine code monitor|wozmon]] variables
|-
|0x002C - 0x00FF
|212 Bytes
|RAM
|-
|0x0100 - 0x01FF
|256 Bytes
|6502 processor stack
|-
|0x0200 - 0x027F
|128 Bytes
|wozmon keyboard input buffer
|-
|0x0280 - 0x0FFF
|3456 Bytes
|RAM
|-
|0x1000 - 0xC027
|
|Unused
|User expandable RAM / [[Input/output|IO]]
|-
|0xC028
|1 Byte
|[[Apple I#Apple Cassette Interface expansion|ACI]] port to write to cassette
|
|-
|0xC029 - 0xC0FF
|
|Unused
|User expandable RAM / IO
|-
|0xC100 - 0xC1FF
|256 Bytes
|ACI ROM
|When ACI card is inserted
|-
|0xC200 - 0xD00F
|
|Unused
|User expandable RAM / IO
|-
|0xD010 - 0xD013
|4 Bytes
|PIA (Peripheral Interface Adapter)
|Keyboard and Display
|-
|0xD014 - 0xDFFF
|
|Unused
|User expandable RAM / IO
|-
|0xE000 - 0xEFFF
|4Ki (4096 Bytes)
|RAM
|8K systems
(standard system, can load wozbasic)
|-
|0xF000 - 0xFEFF
|
|Unused
|User expandable RAM / IO
|-
|0xFF00 - 0xFFFF
|256 Bytes
|PROM (wozmon)
|Programmable read-only memory
|}
[[File:Apple-1-wozmon-ready-prompt.gif|alt=A backlash character at the top-left of the screen and a blinking ampersand character below it|thumb|208x208px|The Apple-1 system monitor ready prompt]]

===Video and Input===
The Apple I included built-in [[computer terminal]] circuitry with [[composite video]] output. To use the computer, a user-supplied [[composite monitor]] and [[ASCII]]-encoded [[Computer keyboard|keyboard]] needed to be connected. If a monitor was not available, a standard [[television set]] could be used along with an [[RF modulator]]. In comparison, competing machines generally required an expensive dedicated video display terminal or [[teleprinter|teletypewriter]]. This, combined with its single-board construction, made the Apple I an elegant and inexpensive machine for its day, though competitors such as the [[Sol-20]] and [[Sphere 1]] offered similar feature sets.

{{multiple image
| image1            = Apple I 2513.jpg
| alt1              = A close-up of the top-left portion of the Apple I motherboard. The chips are arranged in a grid. One chip is larger than the rest and is placed horizontally rather than vertically.
| caption1          = The large, horizontal chip on the top-left of the main board is the [[Signetics 2513]] [[character generator]].
| image2            = Signetics-2513.png
| alt2              = A table with four rows of 16 pixelated characters. There is no room for lowercase letters. The square bracket characters are noticeably thicker than the other symbols.
| caption2          = The Apple I character set
| direction         = vertical
}}

{{anchor|Apple I character set}}The computer generated its video output using a [[shift register memory]] and a [[Signetics 2513]] 64×8×5 Character Generator.<ref>{{Cite web |last=Shirriff |first=Ken |title=Inside the Apple-1's shift-register memory |url=http://www.righto.com/2022/04/inside-apple-1s-shift-register-memory.html |url-status=live |archive-url=https://web.archive.org/web/20230606065258/http://www.righto.com/2022/04/inside-apple-1s-shift-register-memory.html |archive-date=2023-06-06 |access-date=2023-08-04 |website=Ken Shirriff's blog}}</ref> It was capable of displaying uppercase characters, numbers and basic punctuation and math symbols with a 5x8 [[pixel font]]:<ref>{{Cite web | url=https://www.datasheetarchive.com/pdf/download.php?id=5065adad5e4757ac90073038091de3931e7380&type=M&term=2513 | title=Datasheet Archive 2513 datasheet download | access-date=April 22, 2022 | archive-date=June 17, 2022 | archive-url=https://web.archive.org/web/20220617123616/https://www.datasheetarchive.com/pdf/download.php?id=5065adad5e4757ac90073038091de3931e7380&type=M&term=2513 | url-status=live }}</ref>

{|{{chset-table-header1|Signetics 2513}}
|-
|{{chset-left1|0x<br />0}}
|{{chset-cell1|Alt+64 - U+0040 COMMERCIAL AT|[[@]]|style=background:#EFF}}
|{{chset-cell1|Alt+65 - U+0041 LATIN CAPITAL LETTER A|[[A]]}}
|{{chset-cell1|Alt+66 - U+0042 LATIN CAPITAL LETTER B|[[B]]}}
|{{chset-cell1|Alt+67 - U+0043 LATIN CAPITAL LETTER C|[[C]]}}
|{{chset-cell1|Alt+68 - U+0044 LATIN CAPITAL LETTER D|[[D]]}}
|{{chset-cell1|Alt+69 - U+0045 LATIN CAPITAL LETTER E|[[E]]}}
|{{chset-cell1|Alt+70 - U+0046 LATIN CAPITAL LETTER F|[[F]]}}
|{{chset-cell1|Alt+71 - U+0047 LATIN CAPITAL LETTER G|[[G]]}}
|{{chset-cell1|Alt+72 - U+0048 LATIN CAPITAL LETTER H|[[H]]}}
|{{chset-cell1|Alt+73 - U+0049 LATIN CAPITAL LETTER I|[[I]]}}
|{{chset-cell1|Alt+74 - U+004A LATIN CAPITAL LETTER J|[[J]]}}
|{{chset-cell1|Alt+75 - U+004B LATIN CAPITAL LETTER K|[[K]]}}
|{{chset-cell1|Alt+76 - U+004C LATIN CAPITAL LETTER L|[[L]]}}
|{{chset-cell1|Alt+77 - U+004D LATIN CAPITAL LETTER M|[[M]]}}
|{{chset-cell1|Alt+78 - U+004E LATIN CAPITAL LETTER N|[[N]]}}
|{{chset-cell1|Alt+79 - U+004F LATIN CAPITAL LETTER O|[[O]]}}
|-
|{{chset-left1|1x<br />16}}
|{{chset-cell1|Alt+80 - U+0050 LATIN CAPITAL LETTER P|[[P]]}}
|{{chset-cell1|Alt+81 - U+0051 LATIN CAPITAL LETTER Q|[[Q]]}}
|{{chset-cell1|Alt+82 - U+0052 LATIN CAPITAL LETTER R|[[R]]}}
|{{chset-cell1|Alt+83 - U+0053 LATIN CAPITAL LETTER S|[[S]]}}
|{{chset-cell1|Alt+84 - U+0054 LATIN CAPITAL LETTER T|[[T]]}}
|{{chset-cell1|Alt+85 - U+0055 LATIN CAPITAL LETTER U|[[U]]}}
|{{chset-cell1|Alt+86 - U+0056 LATIN CAPITAL LETTER V|[[V]]}}
|{{chset-cell1|Alt+87 - U+0057 LATIN CAPITAL LETTER W|[[W]]}}
|{{chset-cell1|Alt+88 - U+0058 LATIN CAPITAL LETTER X|[[X]]}}
|{{chset-cell1|Alt+89 - U+0059 LATIN CAPITAL LETTER Y|[[Y]]}}
|{{chset-cell1|Alt+90 - U+005A LATIN CAPITAL LETTER Z|[[Z]]}}
|{{chset-cell1|Alt+91 - U+005B LEFT SQUARE BRACKET|[[Square brackets| [ ]]|style=background:#EFF}}
|{{chset-cell1|Alt+92 - U+005C REVERSE SOLIDUS|[[Backslash|\]]|style=background:#EFF}}
|{{chset-cell1|Alt+93 - U+005D RIGHT SQUARE BRACKET|[[Square brackets| ] ]]|style=background:#EFF}}
|{{chset-cell1|Alt+94 - U+005E CIRCUMFLEX ACCENT|[[^]]|style=background:#EFF}}
|{{chset-cell1|Alt+95 - U+005F LOW LINE|[[Underscore|_]]|style=background:#EFF}}
|-
|{{chset-left1|2x<br />32}}
|{{chset-ctrl1|Alt+32 - U+0020 SPACE|&nbsp;[[Whitespace character|SP]]&nbsp;}}
|{{chset-cell1|Alt+33 - U+0021 EXCLAMATION MARK|[[!]]|style=background:#EFF}}
|{{chset-cell1|Alt+34 - U+0022 QUOTATION MARK|[["]]|style=background:#EFF}}
|{{chset-cell1|Alt+35 - U+0023 NUMBER SIGN|[[Number sign|#]]|style=background:#EFF}}
|{{chset-cell1|Alt+36 - U+0024 DOLLAR SIGN|[[$]]|style=background:#EFF}}
|{{chset-cell1|Alt+37 - U+0025 PERCENT SIGN|[[%]]|style=background:#EFF}}
|{{chset-cell1|Alt+38 - U+0026 AMPERSAND|[[&]]|style=background:#EFF}}
|{{chset-cell1|Alt+39 - U+0027 APOSTROPHE|[[']]|style=background:#EFF}}
|{{chset-cell1|Alt+40 - U+0028 LEFT PARENTHESIS|[[(]]|style=background:#EFF}}
|{{chset-cell1|Alt+41 - U+0029 RIGHT PARENTHESIS|[[)]]|style=background:#EFF}}
|{{chset-cell1|Alt+42 - U+002A ASTERISK|[[Asterisk|*]]|style=background:#EFF}}
|{{chset-cell1|Alt+43 - U+002B PLUS SIGN|[[+]]|style=background:#EFF}}
|{{chset-cell1|Alt+44 - U+002C COMMA|[[,]]|style=background:#EFF}}
|{{chset-cell1|Alt+45 - U+002D HYPHEN-MINUS|[[-]]|style=background:#EFF}}
|{{chset-cell1|Alt+46 - U+002E FULL STOP|[[Full stop|.]]|style=background:#EFF}}
|{{chset-cell1|Alt+47 - U+002F SOLIDUS|[[Slash (punctuation)|/]]|style=background:#EFF}}
|-
|{{chset-left1|3x<br />48}}
|{{chset-cell1|Alt+48 - U+0030 DIGIT ZERO|[[0 (number)|0]]}}
|{{chset-cell1|Alt+49 - U+0031 DIGIT ONE|[[1 (number)|1]]}}
|{{chset-cell1|Alt+50 - U+0032 DIGIT TWO|[[2 (number)|2]]}}
|{{chset-cell1|Alt+51 - U+0033 DIGIT THREE|[[3 (number)|3]]}}
|{{chset-cell1|Alt+52 - U+0034 DIGIT FOUR|[[4 (number)|4]]}}
|{{chset-cell1|Alt+53 - U+0035 DIGIT FIVE|[[5 (number)|5]]}}
|{{chset-cell1|Alt+54 - U+0036 DIGIT SIX|[[6 (number)|6]]}}
|{{chset-cell1|Alt+55 - U+0037 DIGIT SEVEN|[[7 (number)|7]]}}
|{{chset-cell1|Alt+56 - U+0038 DIGIT EIGHT|[[8 (number)|8]]}}
|{{chset-cell1|Alt+57 - U+0039 DIGIT NINE|[[9 (number)|9]]}}
|{{chset-cell1|Alt+58 - U+003A COLON|[[colon (punctuation)|:]]|style=background:#EFF}}
|{{chset-cell1|Alt+59 - U+003B SEMICOLON|[[Semicolon|;]]|style=background:#EFF}}
|{{chset-cell1|Alt+60 - U+003C LESS-THAN SIGN|[[Less-than sign|<]]|style=background:#EFF}}
|{{chset-cell1|Alt+61 - U+003D EQUALS SIGN|[[=]]|style=background:#EFF}}
|{{chset-cell1|Alt+62 - U+003E GREATER-THAN SIGN|[[Greater-than sign|>]]|style=background:#EFF}}
|{{chset-cell1|Alt+63 - U+003F QUESTION MARK|[[?]]|style=background:#EFF}}
|}
{{legend|#EFF|Symbols and punctuation}}

===Apple Cassette Interface expansion===
{{Listen image
| main_image         = Apple Cassette Interface.jpg
| main_image_caption = The Apple Cassette Interface expansion card. There are two [[phone connector (audio)|phone connector ports]] for reading and writing programs to a connected cassette deck.
| main_image_alt     = A green circuit board with six chips in a row. There are two phone jacks in the top-left corner. A gold edge connector runs along the bottom of the board.
| filename           = Apple Cassette Interface BASIC.wav
| title              = Apple BASIC cassette tape
| description        = This cassette tape was distributed with the Apple&nbsp;I. Playing this file into an Apple Cassette Interface will load Apple BASIC.
}}
A cassette interface was available in the form of an optional add-on for the Apple I's expansion slot. A [[cassette deck]] plugged in to the expansion's [[Phone connector (audio)|phone connector ports]] could be written to and read from as a form of [[removable storage]]. The only alternative to the interface for loading programs was typing machine code by hand, making the add-on "ubiquitous".{{sfn|Owad|2005|p=3}}

The expansion came with a free cassette tape containing [[Steve Wozniak]]'s [[Integer BASIC]] interpreter. Other software tapes were supplied "at minimal cost"<ref name="byte ad"/> including [[porting|ported]] video games such as ''[[Hamurabi (video game)|Hamurabi]]'', ''[[Lunar Lander (video game genre)|Lunar Lander]]'' and ''[[Star Trek (1971 video game)|Star Trek]]''.<ref name="1977 price list"/>