SlimeGENBA-LUI
Legacy UI (LUI) preservation layer for mainframe modernization.
日本語版: 現場 Mode · 海外版: Legacy UI / LUI
bms_to_ui. Available under NDA for evaluation.
The problem we solve
Mainframe operator floors run on 30-year-old IBM 3270, Hitachi F-series, Fujitsu MSP, and NEC ACOS terminals. Veteran operators do blind-type at ~1,500 transactions per day using only TAB / ENTER / PF keys — no mouse. When forced into mouse-driven web UI, productivity drops to ~400-600 / day, error rates rise, and operators reject the new system. Modernization stalls.
Competitors (Micro Focus, Blu Age, AWS Mainframe Modernization, mLogica) all assume web-first replacement. SlimeGENBA-LUI takes the opposite approach: preserve the LUI as a first-class deliverable, offer modernization as a strictly additive option.
How it works — the 2-layer architecture
| Layer | Name | Purpose | Customer benefit |
|---|---|---|---|
| 1 | LUI (Legacy UI / 現場 Mode) | Terminal-authentic emulation. 3270 / XMAP / MELT / OLF data-stream and screen layout preserved. | Operator skill kept intact. No retraining. Day-1 productivity matches the existing system. |
| 2 | MUI (Modern UI) | Modern web overlay. Same screen structure, modern theme, identical keyboard semantics. | Optional, opt-in per user. New hires can use modern interface, veterans keep LUI. Both layers run from the same emitted code. |
Vendor coverage. Layer 1 is vendor-specific (different terminal protocols per vendor), Layer 2 is vendor-agnostic. Currently shipping IBM BMS support; Hitachi XMAP, Fujitsu MELT, and NEC ACOS-OLF parsers ship as sibling Rust crates as NDA samples become available.
Competitive comparison
| Capability | Micro Focus / Blu Age / AWS MMA / mLogica | SlimeGENBA-LUI |
|---|---|---|
| Operator can keep using TAB/ENTER/PF blind-type | No — forced to web UI | Yes — Layer 1 is exactly the original semantics |
| 4-vendor terminal coverage (IBM + Hitachi + Fujitsu + NEC) | No (IBM only or limited) | Yes — same Layer 2 wraps all four |
| Progressive opt-in modernization | All-or-nothing migration | Per-user choice between LUI and MUI |
| No-framework deployment (single HTML file per map) | Build pipeline + framework required | Yes — vanilla HTML+JS, runs anywhere |
| Real-corpus behavioural test coverage | Not disclosed | 11 / 11 real maps emit (IBM CBSA · cics-genapp · CLBS, internal) |
Technical specifications
- Emitter: Rust crate
bms_to_ui, ~660 lines, std-only (no-external-lib) - Input: CICS BMS macro source (DFHMSD / DFHMDI / DFHMDF), with line-continuation support (
*andXconventions) - Output: Self-contained HTML + vanilla JS, ~14-37 KB per emitted page, no build step, no npm, no CDN
- Picture-clause editing:
9,Z,.,,(suppression-linked),B,/,$(static + floating),+/-(static + floating),X(N),A(N),OCCURS=N - Test coverage: 19 / 19 Rust unit tests covering picture editing semantics; 11 / 11 corpus BMS maps emit successfully
- Phase G integration:
terminal_emulation_layer.{html,js}+ui_virtual_layer.{html,css}emit pair plugs into SlimeNENC Phase G pipeline (BMS / XMAP / MELT / OLF → common IR → 2-layer UI emit)