Macintosh LC 475 and Quadra 605 Developer Note
The Macintosh LC 475 and Macintosh Quadra 605 Developer Note is Apple's 1993 hardware description of the Macintosh LC 475 and Macintosh Quadra 605, published by Apple's Developer Press for developers of compatible hardware and software. The hosted file is a 65-page PDF produced in February 1995. It describes the two machines at the level of ports, connectors, custom chips and the expansion slot; it is not a repair manual.
Contents
[edit | edit source]- Preface: About This Note (p. vii)
- Chapter 1, Introduction (p. 1): summary of features and comparison with the Centris 650 (p. 2); appearance (p. 3); external video monitors, video connector pinout and monitor sense codes (pp. 5-7); RAM expansion, 72-pin SIMM signal assignments and mechanical specification (pp. 7-12); video RAM (p. 13); serial ports (p. 13); floppy connector (p. 14); SCSI (p. 15); ADB (p. 16); sound (p. 17); keyboard, reset and NMI (p. 18); expansion slot (p. 19)
- Chapter 2, Architecture (p. 21): block diagram, 68LC040, custom ICs MEMCjr, PrimeTime, DFAC II, Cuda and Antelope (pp. 22-25); address maps (p. 26); video timing parameters (p. 28)
- Chapter 3, Expansion (p. 33): slot pin assignments and signals (pp. 34-38); compatibility with older cards (p. 39); card design, connectors, power and address space (pp. 39-41)
- Chapter 4, Software (p. 43): ROM and system software changes, machine identification (p. 44)
- Index (p. 47); foldouts for expansion card design (p. 51)
What it settles
[edit | edit source]- RAM: 4 MB on the logic board and one 72-pin SIMM socket for SIMMs of 80 ns or faster, 1 to 32 MB, for 5 to 36 MB in total (pp. 7-8).
- ROM: 1 MB soldered to the logic board (p. 2). Apple's LC Series/Quadra 605 Service Source prints "512K expandable to 1 MB".
- VRAM: two 68-pin VRAM SIMM sockets, no VRAM on the board; the pair holds 512 KB or 1 MB, both SIMMs must be the same size, and no more than 1 MB is recognised (p. 13). Table 1-2 (p. 5) gives the maximum pixel depth for each monitor size and VRAM amount.
- Processor: the 68LC040 is in a socket and can be replaced by a 68040 to add an FPU; an expansion card cannot supply an FPU (p. 22).
- Expansion slot: accepts 96-pin LC II and 114-pin LC III cards but is not a processor-direct slot; it runs at 16 MHz and is not connected to the 68LC040, so accelerators, 68882 FPU cards and cache cards do not work (pp. 19, 39). A card may draw 800 mA at +5 V, 20 mA at −5 V and 200 mA at +12 V, 4 W in total (p. 40, Table 3-3).
- Sound: stereo output, mono recording; the input jack is line-level and takes the Apple PlainTalk microphone, not the LC and LC II microphone; plugging into the output jack disconnects the speaker (pp. 17-18, 25).
- Ports: the modem port is a 9-pin mini-DIN socket with +5 V on pin 9 for up to 100 mA; ADB and modem devices share 500 mA (pp. 13-14, 16).
- Reset and NMI: Control-Command-Power restarts and Command-Power gives an NMI; there is no programmer's switch (pp. 18-19).
- Machine identification: gestaltMachineType 89 for the LC 475 and 94 for the Quadra 605 (p. 44).
What it does not contain
[edit | edit source]No schematic, no component values, no parts list and no power-supply specification: the only power figures are the expansion-card budget and the +5 V limits on the ADB and modem ports. It has no battery information and no service procedures; for those see Macintosh LC Series/ Quadra 605 Service Source. The Appendix mentioned in the preface is not in the contents list or the file.
Pages that cite this document
[edit | edit source]- Macintosh LC 475 (specifications, memory, sound, expansion slot)
- Macintosh LC 475 General Maintenance (ROM, VRAM, processor socket)
- Macintosh LC 475 Troubleshooting (VRAM, sound input, reset keys)
- Macintosh Quadra 605 General Maintenance
Download: Macintosh LC 475 and Quadra 605 Developer Note.pdf (558 KB)