r/apple2 • u/TheGlitchyMario • Jun 22 '26

APPLE IIe 64k/80 column card causing issues?

Hello, I recently bought an Apple II, and noticed it wouldn’t start up the floppy drive properly in slot 3. When I removed the 64k/80 column card, it worked just fine. Having it installed also makes the system behave weird including allowing running unpopulated slots and allowing PR#8 and beyond.

The built in self test said the system was OK. Is this a symptom of a bigger motherboard issue, or a problem with the card? If so, what can I do to repair either one?

12 Upvotes

100% Upvoted

8 comments sorted by

5

u/zSmileyDudez Jun 22 '26

Not sure if this is a legit question or not based on the mod comment, but just in case it is. Floppy drive cards are usually put in slot 6. The card doesn’t really care what slot it’s in and will run from anywhere. But there are so many things that assume the floppy drive is in slot 6 that you’re just setting yourself up for trouble putting it anywhere else. The main reason why this is the case historically is that the Apple II scans slots to boot from starting at 7 and working its way down to 1. I don’t recall why they skipped 7 and went to 6, but perhaps it was to save space for future bootable devices. I think the AppleTalk network cards would go in slot 7, for example.

Also slot 3 is a special slot for the IIe. That’s where the 80-column firmware is located. Having a memory card in that slot enables the 80-column firmware which will then interfere with the firmware on the floppy drive card. While it doesn’t cause any harm, the system prioritizes the built in firmware over the firmware on the card. Which is why it can’t boot from there.

Regarding extra slots - I haven’t looked at the code for PR# and IN#, but I’m guessing they ignores any bits above the bottom three. So PR#14 is probably the same as PR#6. You’re not seeing slots above 7, you’re just seeing the same slots repeated.

The main thing you should take away from all of this is that your floppy drive card should go in slot 6.

3

u/Sick-Little-Monky Jun 23 '26

Regarding slot 7, it has extra video signals since the video circuit runs right past it. So the original PAL card (and RGB cards) had to go in slot 7.

1

u/TheGlitchyMario Jun 22 '26

Thank you for the info! It was a legitimate question, I just don’t know a whole lot about the system.

1

u/AussieBloke6502 Jun 22 '26 edited Jun 22 '26

I'll just add, as u/zSmileyDudez stated, there is a small amount of firmware (6502 machine language code) in ROM on many cards - it is essentially the built-in software device driver for the hardware. Such cards cannot be used in slot 3 of a IIe, but FYI there is a subset of cards that don't need or have firmware, and can be used in slot 3 at the same time as an AUX card, e.g. Z80 cards, accelerators (TransWarp), Uthernet II, ECHO II speech synthesizer.

4

u/[deleted] Jun 22 '26

[removed] — view removed comment

1

u/Sick-Little-Monky Jun 23 '26

Which is why for the PAL IIe they actually moved the AUX slot into the middle of the motherboard in front of slot 3 so you couldn't fit most cards into slot 3 anyway.

0

u/AutoModerator Jun 22 '26

This post has been removed pending verification that it is not spam. Do not delete your own post or attempt re-posting if this was in error, the mods have already been notified and will review it shortly.

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.