Wouter's Apple Macintosh page

Macintosh the first

I bought my first Apple Mac from the Cash Converters for R200.

Before this, all of my Apple experience was with the Apple ][+, and I didn't know squat about Macs. This one turned out to be a bit of a mystery. The case is marked Mac Classic II (M4150, CK2040HVD15), but the motherboard is the standard 68000 Classic (M0420). It had 4MB RAM and a 40MB Quantum hard drive. So...

How to install a bigger hard drive in your Mac Classic

There are basically two issues here, namely

How to get software from the Internet to the Mac, and
How to format the hard drive.

The first is not too much of a problem, since the Mac Classic has a 1.44M floppy drive. Older macs used the 400 and 800k drives with Woz' special RLL encoding, which can't be accessed by anything except a Mac. You'd probably have to "bounce" through a Mac that can read 1.44M floppies and write 800k ones.

OK, first things first. You need a system disk. System 6.0.8 is probably the best for a Classic Mac.

I downloaded two files from Apple, namely SSW_6.0.8-1.4MB_Disk1of2.sea.bin and SSW_6.0.8-1.4MB_Disk2of2.sea.bin.

Drag-and-dropping these files into Aladdin Expander 5.1 gives two .sea files, and repeating the process gives two files with no extension and length 1 474 644.

I opened these files using Cygnus Hex Editor and chopped off the first $54 (decimal 84) bytes, save as .dsk (1 474 560 bytes long). These .dsk files can be written to stiffy using HFVExplorer 1.3.1.

You can also use VMac to manipulate files inside the .dsk images before writing the .dsk to disk.

Formatting a new hard drive

You need third party software to format any non-Apple hard drive. As far as I know, the following will all work :

Lido 7
SCSITools V2.0
HD SC Setup

I used Lido 7 and it works well. If you open lido756.hqx with HFVExplorer (copy it from your PC drive to one of the virtual volumes), you will end up with a lido7.56.sea file. Double click on this file in VMac (or I guess on a real Mac :-) to extract the archive.

Memory upgrade

The Mac Classic has 1MB on the motherboard, and a space for an expansion card with another 1MB soldered to it, as well as space for two SIMMs.

My Classic came with 4MB of RAM installed. This is also the maximum, the (stupid, IMO, but hey, hindsight is the only exact science) reason being that the ROM is mapped at $400000.

Macintoshes the second to fifth

2004-02-02: I bought four Macs for R300.

Mac Plus M0001A 930512512MP (?)
Mac Plus M0001A E915Q0BM5880
Mac Plus 1Mb M0001A F834CX5M0001A
Mac Classic M0420 SG0400CD11

The Mac Plus was sold with 256K of memory, but mine have been upgraded to 1MB (4 SIMMs total).

Serial # Model Number PCB ID PCB Serial # Pic

930512512MP (?) M0001A 820-0174-D SG93307S212A

E915Q0BM5880 M0001A

F834CX5M0001A M0001A

SG0400CD11 M0420 820-0390-03 SG046RC803F3

CK2040HVD15 M4150 820-0390-B CK2023KT044C

Serial #	Model Number	PCB ID	PCB Serial #
930512512MP (?)	M0001A	820-0174-D	SG93307S212A
E915Q0BM5880	M0001A
F834CX5M0001A	M0001A
SG0400CD11	M0420	820-0390-03	SG046RC803F3
CK2040HVD15	M4150	820-0390-B	CK2023KT044C

Hardware information

Mac Plus

While the original Macintosh had 128k RAM, the motherboard design (see schematic) allowed for 512k.

Upgrading the 512k "Fat Mac"&; needed a redesigned motherboard. This was the "Plus", with 1MB on the motherboard, which could be expanded to 4MB (Scans of PCBs).

The original 512k design and the Plus makes extensive use of PAL technology. See http://www.mactech.com/articles/mactech/Vol.01/01.11/PAL/.

Kryten Droid has some info on what's inside the PALs.

512K MAC:
 
ASG  16R8 Disk speed control, sound generator.
BMU0 16R4 Ram control (read, write, DTACK)
BMU1 16L8 Address decoding
LAG  16R8 Video generator
TSG  16R6 Divide by 2, divide by 4.25.
TSM  16R4 Generates RAS and CAS for DRAM
 
Mac Plus:
 
BMU1 16L8 341-0514-A
BMU2 20R4 341-0520-A
CAS  20L8 341-0519-A
LAG  16R8 341-0515-A
TSG  16R6 341-0516-A
TSM  16R4 341-0522-A

Datasheets at Texas Instruments: 16L8, 16R4, 16R6, 16R8, 20L8, 20R4, 20R6, 20R8.

The Plus uses 9 bit SIMMs, while the Classic uses 8 bit SIMMs.

ROMs in my Plus are 342-0341-C (hi) and 342-0342-B (lo). Read these using the settings for 27C512.

Classic

The Classic is a Plus using surface-mount technology on a smaller (half the size) motherboard (Scans of PCBs). The six PALs are replaced by a gate array from VLSI (UI4, BBU) and one PAL (UL1, CAS PAL). A fan was added, presumably because of the extra heat from the internal hard drive.

The ROM is a 40 pin 16 bit device from Sharp. The Apple part number for the ROM in my Classic is 341-0813. The pinout matches the Amiga ROM, which is a Macronix MX23C4100. If you want to read your ROM using a programmer, use the settings for the 27C400.

The two motherboards I have are 820-0390-03 (1990, Assembled in Thailand) and 820-0390-B (1990, 1991, Assembled in Ireland). The only differences I can spot are in the silkscreen. The same components are used in the same places and as far as I can see the board was not rerouted -- all the tracks are identical.

The linux-m68k guys have a lot of information on the Mac hardware.