What Antler runs on
The target is the XT class: an 8088 or 8086, 640K of conventional memory, an 8-bit bus and whatever cards the machine happens to have. The build system bakes one machine profile into the image so the kernel and services come up matched to the hardware, no runtime probing roulette.
Machine profiles
| Profile | Machine |
|---|---|
pcxt | IBM PC/XT class — the generic 8088 baseline |
pc1640 | Amstrad PC1640, with its integrated PEGA video and motherboard mouse |
pc1640-dd | Amstrad PC1640 DD variant |
tandy | Tandy 1000 family |
video7 | XT fitted with a Video Seven VGA card |
qemu | Stock QEMU's PC emulation (see running Antler) |
Video
GEM VDI drives the adapter directly. Supported: VGA, EGA, CGA, Hercules, and the Amstrad PEGA (the PC1640's on-board EGA-compatible chip). The desktop's home resolution is EGA 640x350 in 16 colours; CGA and Hercules get monochrome desktops at their native resolutions. VDI loads the original GEM code-page, system and adapter-specific bitmap fonts so text metrics match the classic desktop exactly.
Storage
- XTIDE — the default root disk path, direct PIO to an XTIDE-style 8-bit IDE controller. A CF card on an XTIDE card is the natural home for the system.
- MFM / ST-506 — real vintage hard disks behind a Xebec controller.
- BIOS INT 13h — a firmware-backed block backend so the image also boots on machines (and emulators like stock QEMU) where we dont drive the disk controller ourselves.
- Floppy — NEC 765 controller, with FAT12 floppies mounting alongside the ext2 root for getting files in and out.
Input
- Keyboard — the XT keyboard interface, scan-code set 1. A buckling-spring Model F is the reference typing experience.
- Microsoft serial mouse — on any of COM1 through COM4; the pointer service leases the configured UART.
- Amstrad mouse — the PC1640's motherboard quadrature mouse, read straight from the counter interface.
- Gameport — classic 201-style joystick port support aswell.
Sound
PC speaker PCM — actual sampled audio pushed through the one-bit speaker, which is a party trick I remain fond of. A Sound Blaster driver is there as a build-time alternative for machines that have the card.
Serial and networking
8250/16450 UARTs on COM1 through COM4, shared-IRQ aware. COM1 carries a real getty for serial logins; COM2 is the usual serial mouse spot. On the network side the in-house TCP/IP stack talks to an NE2000 where the machine or emulator provides one (drivers for WD80x3/SMC and 3Com EtherLink boards are in the tree too). DHCP or static addressing, and enough of a stack for IRC, HTTP and NFS to be genuinely usable.