Apple II

Horizontal bars on Apple IIe

Submitted by alexv on March 30, 2024 - 3:05pm

Hello, I have this Apple IIe that won't boot and all I'm getting is horizontal bars. I've done some troubleshooting and so far found that the clock is good and the CPU is getting a reset signal on pin 40. I scoped pins 19 and 20 on the MMU and found that only 19 (ROMEN2) is ouputting a pulse. Pin 20 (ROMEN1) is always in high (off) state. Does this mean that the problem is in the EF ROM? I haven't been able to find any information on whether both of these signals should be on at the same time or if ROMEN1 is off because it has to read the other ROM first.

 

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Apple II+ boot issue: nothing but the "@" symbol

Submitted by GG on March 29, 2024 - 7:07pm

Hello – Today, my Apple II+ is having a boot issue. I’m far from being a technical person and have no diagnostic tools. Any advice would be welcome.

 

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Revisting Alex Freed Z80 Card

Submitted by jbforrer on March 29, 2024 - 12:49pm

Greetings,

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Apple II

just another softSP card.....

Submitted by chrisa850 on March 29, 2024 - 8:43am

After being disappointed with the performance of a similar card that that was being sold, combined with the fact that the licensing for that project had several restrictions, I decided to spend a couple hours with KiCad and draw it from scratch myself. The result is a reduced chip count, and IMO, a better layout in a similar size.

 

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Apple II

Enhancer IIe RGB/64k Card

Submitted by nick3092 on March 27, 2024 - 7:38pm

I came across a Video 7 Enhancer IIe card, which appears to be an RGB and 64k card.  I can't find much info at all on this card.  I know Video 7 made a combo card like this.  But it had a DB15 socket, while this has a 9 pin (and an RCA jack).  It's also much smaller than pictures I can find of the other Video 7 card.  I was able to find a picture of the inside of the Enhancer IIc, and the

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Apple II

Expansion Slot hobby project question

Submitted by gmontag451 on March 26, 2024 - 5:04pm

I have an article which explains how to connect a multiplication/division chip to the Apple II Expansion Slot. It's a simple schematic with 8 pins connected to Expansion Port pins D0-D7 and several control lines. It also provides a program to send values to the chip and fetch the results.

 

The program stores four bytes to locations $C0A0-$C0A3 (Expansion slot one). Three bytes are the numbers to be manipulated and one byte tells the chip which operation to perform. Then it reads the results from these same locations. That's all it does.

 

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Floppy II drive apple 2 europlus does not read

Submitted by AppleWoz on March 25, 2024 - 5:41am

Hi everyone, I have a strange problem with the Apple II floppy drive unit, considering that I have another working floppy disk, I cleaned the lens, straightened the blade where the spiral wheel is and calibrated the motor to 300 rpm so on a mechanical level the unit also works because I swapped the analog board and it works perfectly, I tried to replace all 4 chips ULN2003, 74LS125, CA3146 and 3470 but without any change, it doesn't read. Note that the 3470 chip is definitely faulty because by putting it alone on the working unit it no longer reads, does anyone have any suggestions?

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Apple II

Apple II+ Astec Power Supply - no Yellow RIFA, only a Red WIMA

Submitted by fritzycat on March 25, 2024 - 1:59am

Hello All,

I recently discovered my old Apple ||+ while cleaning out my father's workshop and I brought it home with me. Before attempting to power it up I checked online to see what I could find out about reviving this old tech, and was fortunate enough to find this community.

 

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Apple II

Internal power LED

Submitted by 8BitHeaven on March 22, 2024 - 11:31am

I was thinking about creating an internal LED to indicate when a ][+ or //e is powered up on the workbench.  I just want something clearly reminding me to turn it off before I start connecting or disconnecting stuff.  I anticipate using it with the case off and few cards installed.

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Apple II

Bank Street Laboratory card for the Apple II

Submitted by gmontag451 on March 21, 2024 - 4:55pm

I own two revisions of the Bank Street Laboratory card for the Apple II. This card allowed elementary school students to plug in different probes to measure light, temperature and sound; to emit light and sound; and to record and play back an audio waveform.

 

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