VECTOR 4/8086 - Reset / Entry Path (Z80)From Inside a Vector Graphic SX/5000 (Vector 4/8086 variant)

Listing: 01-reset-entry.asm · 00-jump-table.asm
Related: Self-test suite · Data tables · Memory map

Entry: 0000h → JP 0036h
Menu: 014Fh
Auto-boot: 012Bh

---

Flowchart

RESET 0000
   │
   ▼
JP 0036  cold boot
   │
   ├─ I/O init table (07FD) — 14 port/value pairs
   ├─ Memory mapper probe (port 16h, RAM @ 2000h)
   ├─ SP := 6000h
   ├─ Video port 04h + CRTC 0E/0F
   ├─ Clear console (0521); fill banks D0–DE @ 7000h
   ├─ Banner + revision
   ├─ Main RAM test @ 2200h → fail: print + HALT
   │
   ├─ Phase (5FD8): "01"→menu / "02"→auto / else test 01D2
   │
   ├─ 012B auto-boot if (09AA)≠0 → LOADING → disk → CALL 2400
   │
   └─ 014F menu
         print W/F/T (gated by 09AA / 09AD)
         wait key → @07F4 → handler (return 014F pushed)

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Jump table @ 0000–0035

Offset	Instruction	Role
0000	JP 0036	Cold reset
0003	JP 014F	Main menu
0006	JP 03D5	Kbd status IN A,(01) & 02h
0009	JP 03DA	Kbd data IN A,(00)
000C	JP 0443	Putchar
000F	JP 1000	Floppy (key F)
0012	JP 1066	Winchester (key W)
0015	RET
0018	JP 1434	Geometry + restore
001B	JP 14A8	Read sector(s)
001E	JP 03C0	Config copy
0021	JP 0420	Bank helper
0024	JP 12B1	Config @6600
0027	JP 12FB	Config @6660
002A	JP 13A9	Type21 handoff
002D	JP 155D	HW errors
0030	JP 11C0	Sys errors
0033	JP 012B	Auto-boot

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Cold start @ 0036

A. I/O init (0036–0044)

DI
HL=07FD, B=0E
loop: C=(HL++), A=(HL++), OUT (C),A

Ports: 9D,98,9B×4,91×2,70,9A,1A/1B — see Data tables.

B. Mapper probe (0046–0078)

• OUT (16h),80h; complement test at 2000h
• Programs 9 mapper windows; saves (5FDDh)←E (0 = small RAM)
• SP←6000h

C. Video (007E–009B)

1. OUTI×24 → port 04h from @0827 (delay: double EX (SP),IX)
2. CRTC ports 0Eh/0Fh, 14 registers from @0819

D. Console (009D–00C7)

Step	Role
CALL 0521	Fill ~5800–5F7F spaces; cursor vars
Loop D=D0…DE	CALL 0436 + fill 7000–77FF with 0Fh
OUTI×6 port 1	Extra video setup
OUT (00h),08h	Console control

E. Banner (00CD–00E2)

• 03E4 HL=0585 — title
  
• delay via putchar A=05
  
• 03E4 HL=05A8 — EXECUTIVE - REVISION 2.00 (AC)

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Main RAM gate @ 00EB

HL=2200; write; CP FFh
JR NZ, continue
print "MAIN MEMORY NOT INSTALLED - HALTING"
CALL 03DD / HALT

Open bus / missing RAM reads FFh → fatal.

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Phase / self-test @ 00FF

(5FD8)	Action
"01"	→ menu 014F
"02"	→ auto-boot 012B
other	store "01", print PERFORMING SYSTEM TEST, CALL 01D2
	CF → menu; else store "02", fall into auto-boot

Full suite: Self-test suite · 07-system-test.asm
(PROM / keyboard / disk / memory-screen; continuous mode is menu [T] @01B2.)

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Auto-boot @ 012B

SP=2200
if (09AA)==0 → menu
print "LOADING - PLEASE WAIT"
CALL 15AA / CALL 1072
success: putchar 18h; CALL 2400h
fail → menu

This dump: 09AA=C8h (enabled), 09AD=07h (floppy in menu).

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Main menu @ 014F

SP=2200 / CALL 15AA / putchar 18h
if (09AA)≠0: print [W] @05D2
if (09AD)≠0: print [F] @05FA
print [T] @0667 + lead-in @05CE

Key loop @ 0184

wait: CALL 03D5 / JR Z,wait
      CALL 03DA
      uppercase if ≥'a'
      scan 3 entries @07F4
      PUSH 014F / JP (HL)

Key	Handler
F	1000 floppy
T	01B2 continuous test
W	1066 Winchester

T (01B2): cycle counter @5FDC, CALL 01D2, loop until fail (return to menu).

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Helpers (first use)

Addr	Role	Listing
03D5	Kbd ready	04-helpers-console.asm
03DA	Kbd data
03DD	OUT (00),02
03E4	Print bit-7 string
0436	Map bank OUT (16),~D
0443	Putchar
0521	Clear console

String printer 03E4

LD A,(HL)
BIT 7,A / RES 7,A
JP NZ, putchar     ; final char
CALL putchar / INC HL / JR 03E4