# DEC documentation relevant to the VT1200's XIE server

Downloaded 2026-11-01. These are DEC's own documents, not the X Consortium
XIE 5.0 specification (that one is in `../../xc/doc/hardcopy/XIE/`).

| file | what it is | XIE content |
|---|---|---|
| `DECimage-1200-install-use-EK-V120I-IN-001.pdf` | *Installing and Using the DECimage 1200 Video Terminal*, EK-V120I-IN-001, February 1991 | **The key document.** Appendix C ("X Window Image Extensions") states the terminal's XIE server "uses a subset of the XIE protocol", lists the supported functions (Table C–1) and the pipeline/scaling restrictions |
| `VT1200-user-guide-EK-V1200-UG-001.pdf` | *VT1200 Video Terminal User Guide*, EK-V1200-UG-001 | No XIE mention (checked: zero matches for `XIE` / `image extension`) |
| `VT1200-release-notes-V2.0-EK-V1200-RN-001.pdf` | *VT1200 Video Terminal V2.0 Release Notes*, EK-V1200-RN-001, July 1990 | No XIE mention |
| `DTJ-1991-v03-04-bitonal-image-accelerators.pdf` | Digital Technical Journal **Vol. 3 No. 4 (1991)**, article *Hardware Accelerators for Bitonal Image Processing* (pp. 11–27) | Describes the DECimage accelerator and the S/XIE client–server split; cites *X Image Extension Concepts, Version 2.4* (J. Mauro) in its references |
| `VXT2000-user-information-XIE3.0.pdf` | *VXT 2000+ / VXT 2000 Windowing Terminal User Information*, Appendix C | Later DEC terminal; says "The terminal supports Version 3.0 of the XIE protocol" and gives the XIE pipeline constraints for the accelerator |
| `DECwindows-Motif-OpenVMS-XIE-support.pdf` | *HP DECwindows Motif for OpenVMS New Features* (Alpha V8.3 documentation set) | States that DECwindows Motif shipped XIE from Motif V1.1, includes `XIE$SHRLIB.EXE` and C headers, and supports **XIE 3.0, "not the adopted standard of V5.0"** |

Only PDFs and their `pdftotext -layout` renderings are kept; the renderings are
searchable and are what the quotes below come from.

## What the DECimage 1200 manual says

Appendix C, opening paragraph:

> The DECimage 1200 terminal includes X window image extensions (XIE), an
> extension to the DECwindows server. […] The XIE server for the terminal uses
> a subset of the XIE protocol to display document-size, bitonal images only.

The supported function list in Table C–1 is grouped as:

- **Session services:** `XIEP_INIT_SESSION`, `XIEP_SET_OP_DEFAULTS`,
  `XIEP_QUERY_OP_DEFAULTS`, `XIEP_TERM_SESSION`
- **Resource services:** `XIEP_CREATE_BY_VALUE`, `XIEP_CREATE_BY_REFERENCE`,
  `XIEP_DELETE_RESOURCE`, `XIEP_QUERY_RESOURCE`, `XIEP_EXPORT`,
  `XIEP_FREE_EXPORT`, `XIEP_QUERY_EXPORT`
- **Transport services:** `XIEP_SET_TRANSPORT`, `XIEP_ABORT_TRANSPORT`,
  `XIEP_PUT_TILE`, `XIEP_PUT_STREAM`
- **Geometric:** `XIEP_SCALE`, `XIEP_ROTATE`, `XIEP_MIRROR`, `XIEP_CROP`
- **Process control:** `XIEP_EXECUTE_PHOTOFLO`, `XIEP_ABORT_PHOTOFLO`,
  `XIEP_BIND_PHOTOFLO`, `XIEP_TAP_PHOTOFLO`, `XIEP_SELECT_EVENTS`,
  `XIEP_QUERY_EVENTS`

Restrictions stated there: pipelines may use only scale, crop, rotate, mirror
and export, at most one of each, must end with export, and are limited to 15
definitions; decompression is CCITT Group 3/4 with scaled width ≤ 32768;
rotation is 0/90/180/270 only; `SET_OP_DEFAULTS` bits/pixel must be 1. This
matches the 1-bit StaticGray VT1200 server we are talking to.

## What the DEC documents do **not** give us

DEC's XIE protocol encoding — request numbers, request lengths, reply layouts —
is not in these manuals. The DECimage manual documents the *supported subset
and restrictions*, not the wire format. No public copy of the DECimage
"X Programmer's Reference Manual" / XIE 2.3 protocol specification was found
(the manual list names it, but the document itself is not online in the
collections searched).

So the 2.3 wire differences currently come from two sources:

- raw probes against the live server (`../../evidence/xie_wire_probe.txt`);
- the ROM's own dispatcher, recovered with Ghidra (`../../GHIDRA_XIE.md`).

## Surviving software media (checked)

DEC software media do survive, but the ones checked do **not** contain a 2.3
client kit:

- **ULTRIX 4.0 UWS tape** (`archive.org`, item `dec-ultrix-vax-4.0-tapes`,
  `UWS_4.0A.tap`, 7.6 MB): the setld inventory lists DECwindows X servers,
  fonts and applications — no `XIEproto.h`, `libXIE`, `XieInitialize` or
  `xieperf`.
- **ULTRIX 4.2 unsupported tape** (`dec-ultrix-4.2-unsupported-tape`): no XIE
  strings in the inventory.
- **ULTRIX VAX 4.2 unsupported CONDIST, August 1992**
  (`dec-ultrix-vax-condist-1992-08`): its `cd_contents.dat` lists unsupported
  layered products only — no DECwindows or DECimage.
- **DECwindows Motif for OpenVMS** is the product that did ship XIE on the
  client side, but it is 3.0: "DECwindows Motif includes the XIE client side
  shareable library (`XIE$SHRLIB.EXE`) and C language header files", and it
  "supports V3.0 and not the adopted standard of V5.0". Surviving OpenVMS
  CONDIST CDs and the Tru64/Digital UNIX Software Product Library (Jan 1999)
  are therefore 3.0/5.0-era, not 2.3.
- **DECUS tapes** in the bitsavers archive are user-contributed software, not
  DEC's XIE product kit.

So the answer to "do DEC tape archives survive?" is: media survive, in some
quantity, but no archived kit found so far carries the VT1200's XIE 2.3 client
library or headers. The 2.3 protocol evidence therefore comes from the ROM and
from live probes, not from a recovered DEC SDK.

## The closest surviving source: DEC/AGE's server implementation

The X11R6.1 tree in this directory is not just the 5.0 client. It also contains
the server-side XIE implementation:

```
xc/programs/Xserver/XIE/dixie/request/session.c
xc/programs/Xserver/XIE/dixie/request/tables.c
xc/programs/Xserver/XIE/dixie/request/*.c
```

`session.c` says "Dean Verheiden -- AGE Logic, Inc March, 1993" and calls
`AddExtension(xieExtName, ...)` from `XieInit()`. This is the direct descendant
of the code in the VT1200 ROM, at protocol 5.0 rather than 2.3. It is the best
structural map for the Ghidra analysis: the 26-entry `ProcTable5_00[]`, the
`ProcQueryImageExtension` reply (8 preferred levels, matching the VT1200's
reply length), and the `REQUEST_SIZE_MATCH` length checks all have 2.3
counterparts in ROM. The differences are what the Ghidra report is recovering.

## Provenance

- <https://decdoc.itsx.net/dec94mds/v120iin1.pdf>
- <https://decdoc.itsx.net/dec94mds/v1200ug1.pdf>
- <https://decdoc.itsx.net/dec94mds/v1200rn1.pdf>
- <https://www.filibeto.org/dec/hardware/EK-V1200-UG-001.pdf>
- <https://www.filibeto.org/dec/hardware/EK-V1200-RN-001.pdf>
- <https://www.mrynet.com/FTP/os/DEC/dtj_v03-04_1991.pdf>
- <https://www.filibeto.org/dec/hardware/EK-VXT20-UG-E01.pdf>
- <https://www.digiater.nl/openvms/doc/alpha-v8.3/83final/decwindows/features/DWINDOWS_NF.PDF>

The DECimage and VT1200 files were fetched from the DECdocument mirror at
`decdoc.itsx.net`; the DTJ issue from the mirror at `mrynet.com`; the VXT 2000
manual from `filibeto.org`.

## Related DEC-derived material already in this tree

`../../xc/doc/hardcopy/XIE/SI/xieSIarch.txt` — *XIE Sample Implementation
Architecture*, credited to DEC and AGE Logic, describing the sample
implementation (the one that became XIE 5.0, not the VT1200's 2.3 server).