LIM 4.0 focused EMS board and backplane line for pre-386 platforms, designed for deterministic page-frame mapping and predictable software compatibility.

Standard

LIM EMS 4.0 page-frame compatibility

Frame Windows

D000h and E000h profile sets

Capacity Range

2MB to 8MB banked architecture

Configuration

Register maps with conflict-safe presets

Validation Suite

Lotus 1-2-3, QEMM, DOS extender scenarios

Deployment Form

Single-card and modular backplane builds

The Lo-tech ISA CompactFlash Adapter is an open-source 8-bit ISA card that enables modern CompactFlash storage on IBM PC XT, AT, and compatible systems. Paired with the XTIDE Universal BIOS, it provides silent, reliable mass storage for vintage computers using inexpensive CF cards. The design uses only five through-hole ICs, making it accessible for home assembly. Originally designed by James Pearce at Lo-tech, with hardware schematics and BIOS source code freely available.

Bus Interface

8-bit ISA (fits any PC/XT/AT 8-bit slot)

Storage Media

CompactFlash Type I/II via 40-pin IDE header

I/O Address Range

300h–31Fh (300h–30Fh active)

ROM Address

C800h (32 KB window, directly flashable in-system)

Flash ROM

SST39SF010A 128KB (32 KB used) — in-system programmable

Compatible Flash ICs

SST39SF010A, SST39SF020A, SST39SF040, AMIC A29010

Supply Voltage

5V from ISA bus

IC Count

5 through-hole DIP ICs (basic build)

PCB

2-layer, ISA form factor, through-hole only

BIOS

XTIDE Universal BIOS — GPLv2, supports up to 4 IDE controllers

Transfer Modes

PIO-8 (standard), PIO-8 BIU Offload, PIO-16 BIU Offload

Max Drive Capacity

Unlimited with MS-DOS 7.x/FreeDOS; 8.4 GB limit on DOS 3–6

The Amstrad PC1640 family (1987) helped make affordable IBM PC compatibles mainstream in Europe. This entry tracks a complete PC1640SD setup (monitor + keyboard + boot disk), aligned with the XT-Emporium catalog.

CPU

Intel 8086 @ 8 MHz

RAM

640 KB

Storage

Floppy + HDD variants depending on model

Graphics

CGA/EGA compatible (model dependent)

Manufacturer

Amstrad plc (UK)

Released

1987