K8T is a BBS-first retro communications workstation for BBS hosting, terminal use and classic/modern networking. Its design is optimized for BBS culture, communications, reliable 24/7 operation and practical cost; K8/K16 carry the educational-computer role. It boots into the K8T environment; terminal and BBS are first-class applications.
Core services run on K8T-OS, not on a hidden Linux/ARM computer. Hardware helpers may offload repetitive I/O but expose documented interfaces.
K8T uses the WDC W65C265S as its baseline processor. It provides a W65C816-compatible 8/16-bit CPU, 8-bit external data bus, 24-bit addressing, four integrated UARTs, interrupt facilities, timers and watchdog. The baseline clock is 8 MHz.
K8T uses the commercial CPU directly; a custom FPGA CPU is no longer part of the architecture. FPGA use is optional and should be avoided when a dedicated IC, ordinary logic or a small CPLD provides a simpler/lower-cost solution.
K8T-OS targets native mode after boot and may use 16-bit accumulator/index operation. The native 24-bit address space replaces M1's provisional 64 KiB bank-window architecture. The platform has no fictional hardware supervisor mode or MMU; OS isolation must reflect the real W65C816/W65C265S architecture.
See M2.0 platform baseline for the current memory regions and implementation rules.
K8T has four physical RS-232 ports. Each supports RX/TX, RTS/CTS, DTR/DSR, DCD, RI, independent baud generation, interrupts and hardware FIFO, including classic rates through at least 115200 baud.
Ethernet is mandatory; initial target is 100BASE-TX/RJ45. K8T-OS initially targets ARP, IPv4, ICMP, UDP, TCP and DNS. IPv6 is deferred rather than prohibited.
Internal SSD is the primary persistent store for users, messages, files, logs, captures and queues. Its K8T-facing block interface uses 64-bit LBA and must not impose legacy 2/4 GiB limits. The architectural target is at least 1 TB.
SD is removable boot/recovery/import/export media rather than the preferred write-heavy BBS store.
The provisional native filesystem, K8TFS, must support crash-tolerant metadata, checksums for critical metadata, flush semantics, large files, safe concurrency and snapshot/backup primitives.
K8T is text-first: 80-column modes including 80x25, 80x30 and 80x50, programmable fonts, ANSI/BBS attributes, fast scrolling and virtual consoles.
Keyboard and mouse are standard. Mouse use focuses on selection, copy/paste, scrollback and lightweight navigation.
The W65C265S interrupt facilities, timers and watchdog form the baseline. External Ethernet, storage, video and other devices are integrated into the interrupt design without recreating CPU/peripheral infrastructure in an FPGA.
K8T-OS uses preemptive multitasking. Terminal, BBS, serial nodes, Telnet, Gopher, HTTP, FidoNet/BinkP, IRC, RSS/Atom, networking and storage may execute concurrently. Event-driven service designs are preferred where appropriate.
Users, groups/security levels, messages, message areas, files, file areas, sessions and network metadata form one canonical BBS data model.
Every message/file area has a central policy controlling visibility, read/write, upload/download, authentication, security level and network import/export independently for local/serial BBS, Telnet, FidoNet, Gopher, HTTP, RSS, Atom and IRC gateway.
Protocol servers may not bypass this policy to expose private data.
FidoNet is first-class: addresses, netmail, echomail, packet/bundle handling, nodelists, TIC/file echoes, BinkP over Ethernet and dial-up over RS-232. K8T should operate as a self-contained FidoNet node.
Gopher and lightweight HTTP expose selected BBS content. RSS and Atom publish selected updates. K8T includes an IRC client and may bridge configured BBS areas to IRC.
A future qualification must demonstrate four active RS-232 connections, several TCP sessions, BBS message/file activity, Gopher/HTTP requests, FidoNet/BinkP processing, local terminal/IRC use and SSD activity simultaneously, with no lost serial bytes.
The CPU/ISA is now the documented W65C816-compatible W65C265S architecture. Remaining open items include exact external device mappings, physical video/input connectors, scheduler quantum/context ABI and K8TFS on-disk format.