Library — classic

1. Two library worlds (do not blur)

World	Home	CPUs	Typical product
Classic	libsrc/target/<name>/ (historic fcntl/stdio/gfx) + libsrc/classic/	Z80, IXIY, Z180, 8080, 8085, gbz80, …	*_clib.lib, cpm8085_clib.lib, …
Newlib	Was libsrc/newlib/target/<name>/; migrated → libsrc/target/<name>/ beside classic	Z80-class (-clib=new / sdcc_ix / sdcc_iy)	lib/clibs/{sccz80,sdcc_ix}/<target>.lib

Hard rules

1. Do not merge classic and newlib stdio cores or fcntl open owners in one link without a designed bridge.
2. Prefer sharing device / thin driver layers, not cores.
3. CLIB selects newlib; machine SUBTYPEs usually stay classic-owned (esp. CP/M’s 150+ machines).
4. After a path move, put the target name in MIGRATED_TARGETS in libsrc/newlib/Makefile so builds use ../target/<name>.

Mixed tree hazard: when newlib Z80+ sources land under libsrc/target/cpm/ next to classic multi-CPU code, isolation is list ownership (*.lst), never broad globs. Classic 8080/8085 images must never pull newlib objects (Z80-only opcodes / calling conventions).

---

Classic I/O patterns (from target work)

Hybrid classic+newlib consoles (rc2014-8085 lesson)

When a CRT mixes classic fgetc_cons/fputc_cons with newlib-style startup:

• FILE init flags must match classic expectations (18 / 20 = _IOSYSTEM|_IOREAD / _IOWRITE).
• Wrong flags (19/21 with spurious _IOUNGETC) made first getchar return NUL.
• Hybrid clib lists must not pull full newlib fcntl/stdio/threads.
• Build: classic <stdio.h> must win include order (-I…/include before _DEVELOPMENT/common) when the hybrid needs classic stdin/stdout objects.

Cooked line input: newlib vs classic (general)

World	Line API	Who echoes / edits
Newlib	POSIX getline / getdelim	console_01 (line mode, echo, BS, CR/LF cook) via tied oterm
Classic	No getline	fgets on stdin → fgets_cons (echo, DEL, optional soft cursor)
Classic raw	fgetc / fgetc_cons	No line editor — app must implement if needed

Rules of thumb

1. getline is newlib-only. Never expect it on 8080/8085 classic products.
2. One cook layer only. If the driver/fgets_cons already echoes, do not also echo in app code (double echo).
3. Hybrid CRTs that only bind fgetc_cons/fputc_cons are raw. App-level line readers (e.g. shell ya_getline) are compensating for classic, not for the CPU.
4. Prefer fgets / fgets_cons on classic instead of reimplementing line edit. On serial targets, disable soft cursor if needed (CLIB_DISABLE_FGETS_CURSOR=1 — already set for rc2014-8085).
5. Align dual-CPU apps (Z80 newlib + 8085 classic) at a single call site with #ifdef, not by linking newlib stdio into 8085 images.

Dual-port FILE* vs classic ttyin macros

	Newlib CRT	Classic hybrid (e.g. uart85)
Second port	Real drivers: m4_rc_01_input_uartb(_ttyin, …) etc.	Often only stdin/out/err → primary UART/ACIA
ttyin / ttyout in headers	extern FILE *	Classic macros → _sgoioblk[3]… slots
Meaning	Instantiated streams	Declaration/slots ≠ working UARTB console

fgetc on classic special-cases stdin → fgetc_cons. Assigning input = ttyin does not create a second cooked port unless the CRT initialises that slot and a driver path exists. For dual-port on hybrid: either an active-console global in fgetc_cons, or real second-stream CRT work — do not copy newlib’s input = ttyin pattern blindly.

CP/M IOBYTE seeds (firmware shells)

Shell may seed bios_iobyte before handing off to CCP; BIOS copies it to page-0 IOBYTE.

• CON is low 2 bits (CRT vs TTY, etc.).
• Hardware-specific high bits (e.g. 8085 module LST → SOD) may require seeds like 0x81 / 0x80, not bare 1 / 0. Match the BIOS list/const decode, not “Z80 values”.

---

Agent rules

1. Classic 8080/8085 images must never pull newlib objects (Z80 opcodes / conventions).
2. Isolation is list ownership (*.lst), never broad globs over mixed trees.
3. Line input: fgets → fgets_cons; no getline.
4. Runtime: libsrc/l/sccz80/7-8085/, 8-8080/, 8-gbz80/, … → crt0 libs in lib/clibs/.

Related

• Newlib world: library-newlib
• Layout: style-libsrc-layout
• Targets: target-cpm, target-rc2014; host TIMER / suites use +test