docs(dtj): archive the full DTJ Vol. 3 No. 4 (Fall 1991) issue

The tree only had two excerpts of this issue, not the issue: a text-only
reflow of article 2 (X Window Terminals) and a 17-page scan of article 1
(Hardware Accelerators for Bitonal Image Processing). Add the complete
83-page issue from vmssoftware.com, plus a pdftotext rendering and a note
recording provenance, contents and how the two excerpts relate to it.

md5 46e69c98eb669fabec7a6ce704d35850, 4,882,168 bytes, 2006 Paper Capture
OCR (so the text layer carries OCR errors).

docs/DTJ-1991-v03-04_full-issue.md

@@ -0,0 +1,52 @@
+# Digital Technical Journal, Vol. 3 No. 4 (Fall 1991) — the full issue
+
+`DTJ-1991-v03-04_full-issue.pdf` is the **whole 83-page issue**,
+*Image Processing, Video Terminals, and Printer Technologies*, Digital
+Equipment Corporation, Fall 1991 (documentation number `EY-H889E-DP`,
+ISSN 0898-901X). `DTJ-1991-v03-04_full-issue.txt` is its
+`pdftotext -layout` rendering, kept so the text is searchable with `rg`.
+
+## Provenance
+
+- Source: <https://vmssoftware.com/docs/dtj-v03-04-1991.pdf>
+- Fetched: 2026-11-01
+- Size: 4,882,168 bytes
+- `md5 46e69c98eb669fabec7a6ce704d35850`
+- 83 pages, 601.2 × 829.2 pt; OCR scan made 2006-04-08 with
+  Adobe Acrobat 7.05 Paper Capture (so the text layer is OCR, with the usual
+  OCR errors — "Techuologies", "j ournal", `1`/`l` mixes).
+
+## Contents
+
+| pages | item |
+|---|---|
+| 1–6 | Foreword (Larry Cabrinety) and author biographies |
+| 7–8 | Editor's Introduction (Jane C. Blake) |
+| 9–25 | *Hardware Accelerators for Bitonal Image Processing* — Christopher J. Payson, Christopher J. Cianciolo, Robert N. Crouse, Catherine F. Winsor |
+| 26–35 | *X Window Terminals* — Björn Engberg, Thomas Porcher |
+| 36–42 | *ACCESS.bus, an Open Desktop Bus* — Peter A. Sichel |
+| 43–54 | *Design of the DECprint Common Printer Supervisor for VMS Systems* — Richard Landau, Alan Guenther |
+| 55–60 | *The Common Printer Access Protocol* — James D. Jones, Ajay P. Kachrani, Thomas E. Powers |
+| 61 ff. | *Design of the Turbo PrintServer 20 Controller* — Guido Simone, Jeffrey A. Metzger, Gary Vaillette |
+
+The two articles with direct VT1200 content are the first two: the bitonal
+accelerator paper is the DECimage 1200 / S/XIE material, and *X Window
+Terminals* is the VT1000 / VT1200 / VT1300 / VXT 2000 design paper (it is the
+source the Lance / font-daemon analysis quotes as
+`docs/DTJ-1991-vol3num4_X-Window-Terminals.txt`).
+
+## Two excerpt copies already in the tree
+
+Neither is a duplicate of this file; both are subsets and both are different
+scans:
+
+| file | what it holds |
+|---|---|
+| `DTJ-1991-vol3num4_X-Window-Terminals.pdf` / `.txt` | article 2 only, *X Window Terminals* (pp. 26–35) — a 20-page text-only reflow, no figures, 28 KB |
+| `../xie/docs/dec/DTJ-1991-v03-04-bitonal-image-accelerators.pdf` | article 1 only, *Hardware Accelerators for Bitonal Image Processing* (journal pp. 9–25) — a 17-page Paper Capture excerpt, 1.6 MB, 590 × 802 pt |
+
+`../xie/docs/dec/README.md` describes the second of those as "the DTJ issue from
+the mirror at `mrynet.com`". That wording overstates what was kept — it is one
+article, not the issue. The file belongs to another worker's in-flight tree, so
+the correction is left to its owner; this note is the authoritative record
+until then.