# IEC 821:1987 — Withdrawn and superseded ISO standards

For IEC 821:1987, item title is Bus — Microprocessor system bus for 1 to 4 byte data; status code is 9599; successor is IEC 821:1991; withdrawn / published date is 1987-06-01, recorded from its source on 2026-08-05.

- **Identifier:** IEC 821:1987 _(verified: appears in the quote below)_
- **Item title:** Bus — Microprocessor system bus for 1 to 4 byte data _(verified: appears in the quote below)_
- **Status code:** 9599 _(verified: appears in the quote below)_
- **Successor:** IEC 821:1991
- **Withdrawn / published date:** 1987-06-01 _(verified: appears in the quote below)_

## What the source says

> 5174,IS,,IEC 821:1987,Bus — Microprocessor system bus for 1 to 4 byte data,Bus système à microprocesseurs pour données de 1 à 4 octets,1987-06-01,1,['35.160'],ISO/IEC JTC 1,9599,,[5175],['en'],471,

## Source

- https://isopublicstorageprod.blob.core.windows.net/opendata/_latest/iso_deliverables_metadata/csv/iso_deliverables_metadata.csv

Last verified: 2026-08-05. Review by: 2027-02-01.
Part of [Withdrawn and superseded ISO standards](https://referencesource.org/iso-standard-supersessions/).