Macintosh Plus ROM history
Readers Digest® condensed version of Macintosh Plus ROM history, or
the truth according to Bo3bdar the everpresent:
1st version (Lonely Hearts, checksum 4D 1E EE
E1):
Bug in the SCSI driver; won't boot if external drive is turned off. We only
produced about one and a half months worth of these.
2nd version (Lonely Heifers, checksum 4D 1E EA
E1):
Fixed boot bug. This version is the vast majority of beige Macintosh Pluses.
3rd version (Loud Harmonicas, checksum 4D 1F 81 72):
Fixed bug for drives that return Unit Attention on power up or reset. Basically
took the SCSI bus Reset command out of the boot sequence loop, so it will only
reset once during boot sequence. This version shipped with the platinum
Macintosh Pluses.
And Bo3bdar saith: "Thou shalt not rev them damn ROMs no more!"
Later that same day...
Bo3bdar Saith Also:
Lonely Heifer was about a 2 byte change,
Loud Harmonica was about 30 byte change.
No other bug fixes in SCSI or elsewhere.
Modified object code directly.
Not possible to get a specific ROM since they are all the same part number.
Shouldn't rely on a specific ROM, there will be no upgrade.
Bo3b Bo3b a boola, a wiff Ba2m Bo1om.
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