Mac 512k

From: Michael Maginnis <celt_at_chisp.net>
Date: Fri Feb 1 11:19:33 2002

Casper Warnich wrote:
> I got an old mac 512k, and when i try to turn it on, a dead man appears
> and a number is show.
> (The number changes every time I turn it on.)
> Can it be because there is no keyboard?
>

It would help to know the SadMac codes (a couple of them, anyway -
though, IIRC changing numbers was usually a RAM or motherboard fault).
Here are the codes for the original Mac ROMs (pulled from Google):

Sad Mac Error Codes
On the original ROMs (128k, 512k, 512ke, Plus):

This numeric code is in two parts: the first two characters are the
class code and the second four are the sub code.

The class code tells what part of the diagnostic program found the error
and the sub class code tells what the error was. In the case of a bad
RAM chip, the sub class identifies the bad chip (this was very helpful
to homegrown upgraders).



Class Code: Sub Code

1 = ROM test failed, Meaningless

2 = Memory test - bus subtest: identifies bad chips

3 = Memory test - byte write: identifies bad chips

4 = Memory test - Mod3 test: identifies bad chips

5 = Memory test - address uniqueness: identifies bad chips


Single Chip Identification

Data Bit : Location : Sub Code Bits

0 : F5 : 0001

1 : F6 : 0002

2 : F7 : 0004

3 : F8 : 0008

4 : F9 : 0010

5 : F10 : 0020

6 : F11 : 0040

7 : F12 : 0080

8 : G5 : 0100

9 : G6 : 0200

10 : G7 : 0400

11 : G8 : 0800

12 : G9 : 1000

13 : G10 : 2000

14 : G11 : 4000

15 : G12 : 8000


Class Code : Sub Code

F = Exception : 0001 Bus error

F = Exception : 0002 Address error

F = Exception : 0003 Illegal instruction

F = Exception : 0004 Zero divide

F = Exception : 0005 Check instruction

F = Exception : 0006 Traps instruction

F = Exception : 0007 Privilege violation

F = Exception : 0008 Trace

F = Exception : 0009 Line 1010

F = Exception : 000A Line 111

F = Exception : 000B Other exception

F = Exception : 000C Nothing

F = Exception : 000D NMI (normal indication)

F = Exception : 0064 Couldn't Read System File into
                 Memory


Mike
Received on Fri Feb 01 2002 - 11:19:33 GMT

This archive was generated by hypermail 2.3.0 : Fri Oct 10 2014 - 23:34:43 BST