What mid-1970s to mid-1980s home computers had their graphics characters added to Unicode 13?

Question

The Unicode 13.0.0 release notes mention among the symbol additions:

214 graphic characters that provide compatibility with various home computers from the mid-1970s to the mid-1980s and with early teletext broadcasting standards

Which computers were these, that did not already have their character sets included in previous versions of the standard? What symbols were added?

Answer 1

The new additions mentioned are mostly to be found in the new Symbols for Legacy Computing block (PDF link) covering the 1FB00–1FBFF codepoint range. This block includes:

• a large number of BLOCK SEXTANT characters like 🬥 BLOCK SEXTANT-1236 ("The term 'sextant' refers to block mosaics divided into six parts." Also note because these definitions are new, these and the following sample characters therefore probably won't render on most machines yet.)
• a large number of partially, diagonally covered block characters e.g. 🭔 UPPER RIGHT BLOCK DIAGONAL UPPER MIDDLE LEFT TO LOWER CENTRE
• various shading/fill symbols like 🮒 UPPER HALF INVERSE MEDIUM SHADE AND LOWER HALF BLOCK and 🮖 INVERSE CHECKER BOARD FILL and 🮟 LOWER LEFT TRIANGULAR MEDIUM SHADE and others
• "character cell diagonals" from 🮠 BOX DRAWINGS LIGHT DIAGONAL UPPER CENTRE TO MIDDLE LEFT to 🮮 BOX DRAWINGS LIGHT DIAGONAL DIAMOND
• miscellaneous other "terminal graphic characters" like 🮲 LEFT HALF RUNNING MAN or 🯊 WHITE UP-POINTING CHEVRON or 🮛 LEFT AND RIGHT TRIANGULAR HALF BLOCK
• ten "segmented digits" characters from 🯰 (SEGMENTED DIGIT ZERO) to 🯹 (SEGMENTED DIGIT NINE)

Two other retro-related symbols were added to a different, pre-existing "Supplemental Arrows-C" block:

• 🢰 U+1F8B0 ARROW POINTING UPWARDS THEN NORTH WEST
• 🢱 U+1F8B1 ARROW POINTING RIGHTWARDS THEN CURVING SOUTH WEST

The proposal for these characters (PDF) recounts that:

A list discussion in April 2017 concerning the “PETSCII” character set, used in various forms by Commodore home computers ranging from the PET (1977) to the C128 (1985), led to the formation of an ad-hoc Terminals Working Group, which is responsible for this document.

The following machines were considered, as well as the Teletext and Minitel services:

• Amstrad CPC (464, 664, 6128, etc.)
• Apple 8-bit computers (II, II Plus, IIe, IIc, III, and the 16-bit IIGS), including MouseText
• Atari 8-bit computers (400, 800, XL, XE) (“ATASCII”)
• Atari 16-bit computers (ST, STE, TT, Falcon), including the GEM windowing system
• Commodore 8-bit computers (PET, VIC-20, 64, 128) (“PETSCII”)
• Commodore Amiga (500, 1000, etc.)
• Mattel Aquarius
• MSX computers (Spectravideo SV-328, Yamaha YIS503II, Canon V-20, etc.)
• Oric computer series (Tangerine Computer Systems)
• RISC OS computers (Acorn, other ARM machines)
• Sinclair 8-bit computers (ZX80, ZX81, ZX Spectrum, and Timex Sinclair equivalents)
• Tandy TRS-80 computers (TRS-80 Model I, Model III, Model 4, Color Computer)
• Texas Instruments TI-99/4A

(List taken directly from the proposal notes.)

There is some other interesting background in that L2/19-025 proposal document explaining various symbols that were considered but ultimately omitted from the specification.

Answer 2

Since the BBC Micro had a Teletext chip (SAA5050) and used it for its MODE 7 and the Teletext character set was added (I believe in that revision), it had its character set added, although, maybe just be coincidence ;)