I am hearing some talk that a LC II rom could work in a classic II. Can anyone here confirm or comment on this?
Classic II ROM
- Thread starter Willj
- Start date
It's fairly likely that it would. Apple had the "universal ROM" approach after the Iici where they tended not to remove stuff from the ROMs. That is to say that when creating a new machine they'd add more stuff to the existing ROM in order to detect and support the new machines while leaving the old stuff in too. Not all of the ROMs are like this, for example the Quadra 660AV/840AV ROMs were sort of a reset and they don't work on the earlier machines. I can't find any official info about the LC II ROM in the Classic II but there is precedent for ROMs later than that working on earlier machines. According to the Quadra 610/650/800 dev note (page 48), their ROM works on all previous 68020, '030, and '040-based Macs: "The ROM software for the Macintosh Centris 610 and Centris 650 and the Macintosh Quadra 800 computers ... supports all Macintosh computers that use 32-bit processors—MC68020 and MC68030 as well as MC68040." So I would not be surprised if the LC II ROM worked in the slightly older Classic II as well.
This issue is now resolved. Turned out not to be the ROM.
EGRET chip pin 15 trace that is the RESET was broken in the battery area. Was very hard to find and was I was checking each chip and each pin traces for continuity, I found this. Repairing this gave me the chime but bad memory sound.
U14 pin 5 power was not getting 5v. Fixed this and now I get chime no memory error. Boot starts but hangs and will not boot all the way.
Anyone have ideas on this??
EGRET chip pin 15 trace that is the RESET was broken in the battery area. Was very hard to find and was I was checking each chip and each pin traces for continuity, I found this. Repairing this gave me the chime but bad memory sound.
U14 pin 5 power was not getting 5v. Fixed this and now I get chime no memory error. Boot starts but hangs and will not boot all the way.
Anyone have ideas on this??
do you have schematics? I am troubleshooting vertical bars issue and am looking for classic II schematics. I have the Bomarc, which help, but they are not complete and have some errors. thanks.
actually. I am getting more confidence in the schematics. And these developer notes have been valuable as well https://cdn.preterhuman.net/texts/computing/apple_hardware_devnotes/Mac%20Classic_II.pdf.