well the Apple II Europlus failed again so I had to repair it again. I also modded the ROM - with Jeff Mazur's help - to implement a simple feature. Plus I finally re-aligned that floppy!
That looks cool! To be fair I would now go for a ROM on a card now - I believe there is an open source language card available? Less hassle, the Apple is untouched and easier to move from one to another. One downside of the one I used is that the pins will inevitably deform the sockets so...
I've got somewhere with the ROMs - I was using a AT27C512 instead of the expected AT27C256 - the extra address line ended up being pulled high all the time so the data I was saving was not accessible.
I got to a point where
- I can run Integer basic. I can type and run a basic code.
- I can...
I've played with lmhex a bit - looks interesting! Is there a way to say import the BIN files and place them on a new file while keeping track of the patterns with colours for example? So far I have discovered the bookmark section but I have a feeling there is a better way!
Thanks!
I know this is an old thread but thanks for this! I struggled for a while because as said the original article has typos in it.
Also it wasn't clear that pin 20 is tied to the programmer AND to the inverter which is then driving 21 which is NOT tied to the programmer.
I've finally got a...
Understood.
I did write a ROM which was mirrored - 32KB + 32KB. Maybe I made a mistake then as that should have worked.
I think I understand now. When the Apple is looking for address 0x0000, because pin 15 is always high, the request is going to 0x8000 instead.
Thanks for the explanation...
Thanks! Fun and interesting indeed!
I understand the 2K = 0x0800 etc. What I am not sure I understand is how you ended up with the below
0x9000
0x9800
0xA000
0xA800
0xB000
0xB800
Thank you so much! I knew I should have checked the pinout!
I guess I could also tie A15 to ground and use the original layout. Or get a 256 :)
I'll try lmHex thanks.
Just for my understanding, how do you come up with those addresses? How does the Apple know where to look when it's switched...
Hi there,
I have an Apple II Europlus (an Apple II+ for Euro market I understand) which might have a faulty ROM as it lands on Monitor every time.
I built a "Rom Replacement" card. I don't have AT27C256 so I used an AT27C512.
The manual of the card says ...
Well, that's what I've been doing so far but
1. I don't want to get out the Apple monitors every time I'm using an Apple
2. The footage is never nice unless you come up with a complex setup to avoid ambient reflections
3. The whole point is to avoid shooting a screen, which is what I've been...
Hi all,
I am looking to capture the video output of the Apple 2 - I know it's a special signal which works-ish with modern monitors and capture devices.
I have just got an OSSC for VGA/RGB/Component capture and there is a "composite add-on" available which is likely based on the Koryuu...
I don’t know how the IWM works but I can tell you that if you remove the write amplifier, the drive boots and reads no problem.
So I suppose that if the writing section of the IWM is broken, you get the same.
If you tried more than one drive then I’m afraid the issue is with the main board.
was the drive working before? The writing circuitry on the drive is driven by a write IC. Without that IC - or with a faulty one - the drive will boot fine and read fine, would just refuse to write.
If you have a spare IC, I would swap it. Or at least re-seat it if the IC is socketed.
The IC...
with "rotor" you mean the stepper motor? Wouldn't that potentially cause damage on the surface if the head is moved and the platters are not spinning?
A friend (who also is on this forum) suggested to keep using it a bit to spread whatever substance they used to have on the platters back in the...