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   🇺🇦 haxadecimal (brouhaha@mastodon.social)'s status on Thursday, 09-Mar-2023 16:42:00 JST 🇺🇦 haxadecimal

   • Julia Evans

   @b0rk Early on, 8 and 16 bits were not common sizes, though very few early machines used 32. The word "byte" was created by the developers of the IBM 7030 "STRETCH" 64-bit .supercomputer (1960). Its integer and logical instructions could operate on groups of bits smaller than a word, from 1 to 8 bits. Most I/O was done in 8-bit increments, using an 8-bit character code unique to Stretch. The sub-word data was addressed on it boundaries, making a power-of-two word size important.

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     🇺🇦 haxadecimal (brouhaha@mastodon.social)'s status on Thursday, 09-Mar-2023 18:42:42 JST 🇺🇦 haxadecimal

     in reply to

     • Julia Evans

     @b0rk While Stretch was considered a commercial failure, many of its technical developments were incorporated into the System/360. The 360 established the byte size as a fixed 8 bits. That ultimately was a major influence on other computers, mainframe, mini, and micro, adopting 8-bit bytes.

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     arclight (arclight@oldbytes.space)'s status on Thursday, 09-Mar-2023 18:42:53 JST arclight

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     • Julia Evans

     @brouhaha @b0rk Note that ACM has Buchholz's post mortem of Project Stretch ("Planning a Computer System") available in PDF form: https://amturing.acm.org/Buchholz_102636426.pdf It's from an era where you could still choose how many bits went into a byte or word, design your own floating point representation, etc.

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     🇺🇦 haxadecimal (brouhaha@mastodon.social)'s status on Thursday, 09-Mar-2023 18:47:54 JST 🇺🇦 haxadecimal

     in reply to

     • Julia Evans

     @b0rk The 8008 used 8-bit bytes because Computer Terminal Corporation designed the architecture for the Datapoint 2200 using 8-bit bytes. The 8008 was designed based on CTC requirements.

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     🇺🇦 haxadecimal (brouhaha@mastodon.social)'s status on Thursday, 09-Mar-2023 18:47:56 JST 🇺🇦 haxadecimal

     in reply to

     • Julia Evans

     @b0rk I'm not sure whether there's any available information regarding specifically why CTC chose 8 bits, but 8-bit bytes were generally becoming commonplace in the late 1960s, in part for IBM compatibility, and in part due to the growing popularity of the ASCII and EBCDIC character codes, which were 7-bit and 8-bit codes, respectively, and 8-bit peripheral devices, including e.g. 8-level paper tape and 9-track magtape (8 data bits).

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