Apple II

Let me introduce myself

Submitted by diycomputers on February 7, 2024 - 12:44pm

Hi,

I started an initiative few years ago to teach ourselves about computers, it was called msxmakers because was initially focused on msx.

our project try to teach ourselves how to build new hardware.

So, my idea is not focus on repairing old hardware but build it, some times using as older chips as Woz, sometimes adding new chips as long as we can study them and understand it, but new pcb designs and with gpl schematics when possible.

Forums: 
Apple II

Monitor recaps: Need parts lists

Submitted by DistantStar001 on February 5, 2024 - 4:30pm

So I have three green phosper displays that need a recap.  The first is an Amdek 300, the second is an Apple Monior ///, and the last is a Kaga KG-12NU.  I also have an Apple Monitor II (the one with a tilt screen) that will fliker initilly, if left idle for an extended period, but stabolizes after a while.

Additionally, I have a Color/Composite Apple //c monitor that needs a recap as well.  Console5 has a kit for the //e model, but I don't know if that translates to the //c.

Forums: 
Apple II

Apple II+ Composite Video issue

Submitted by VIBR on February 5, 2024 - 11:12am

Hello, 

I have an Apple II+ with Video sync issues, 

Using a standard Apple composite monitor, I had vertical sync issues, and I changed a few ICs to fix it : 74LS161 x2 at D11 and D12, 74LS32 at C13 and 74LS32 at C14. 

Now the image is stable with the classic monitor. 

However when I use a Retrotink 2x pro, I do not get any sync (black screen). Using another Apple IIe I succeed with the retrotink. 

Is there any good document explaining step by step  to troubleshoot the apple II video sygnal using an Oscilloscope?

Where to start with ?

Thanks

Forums: 
Apple II

PAL IIe cassette interface

Submitted by afrb2 on February 5, 2024 - 10:54am

I'm having trouble sending audio files to the cassette interface in a IIe PAL version. There are clearly some ciruit changes e.g. no 741, but half an MC1458 opamp seems to be the zero crossing detector.  Is the basic format (frequencies 1kHz/2kHz/ 770Hz) the same, or were there slight differences due to the different clock crystals in these machines?  I guess I could adjust the speed of the recording wav file slightly.

Forums: 
Apple II

Unable to get serial started on IIe to use with ADTPro 2.1.0

Submitted by Sea-Apple on February 3, 2024 - 11:55pm

I'm new to the forum and just pulled my IIe out after being in storage for a long time. I'm using ADTPro 2.1.0 to create some disks, but am having some trouble getting the serial working. When I enter IN#2 and press RETURN, I don't see the APPLE SSC: prompt. What I get is a bracket and then a random character after that.

Example: ]p

I verified that the card is in the second slot from the left as you look at the machine from the front, the dip switches are set to SW1: 1001111 SW2: 1101100, and the jumper block has the arrow pointing up since I'm using a null modem cable.

Forums: 
Apple II

RAM blocks architecture and total RAM amount

Submitted by jaymzleutz on February 3, 2024 - 6:00pm

Hello, gentlemen!

 

I am devouring the masterpiece Understanding the Apple II by Mr. James Sather and the Apple II Reference Manual as well.

So far, so good, but I am stuck on the total amount of RAM available and considered by the system. I am aware that the 6502 processor can read/write 8 bits at a time (8 input/output lines) but has 16 lines available for dealing with addresses.

 

My issues are:

1) If I have 3 rows of 8 columns with a 16k chip at each socket, how can I have "only" 48k of RAM?;

Forums: 
Apple II

Case & power supply screws for //e

Submitted by softwarejanitor on February 3, 2024 - 3:05pm

I have a couple of //e units that are missing one or more of the screws that attach the bottom plate of the machine to the top part of the case and/or the screws that attach the power supply to the base plate.  Does anyone know the specs of the screw types so I can order some?  Maybe a suggestion on the best place to order a few dozen of them or whatever the minimum package size is?

 

Forums: 
Apple II

Logical problem with Apple II europlus error and random freeze

Submitted by AppleWoz on January 30, 2024 - 7:36am

I turned on my europlus today after a long time and I randomly find these errors, what could it be? Thank you

Forums: 
Apple II

simple //e cassette problem

Submitted by dcrowell on January 28, 2024 - 7:47pm

First post!  So I'm sure I'm gonna break a bunch of rules!  :^)  I did search the forum for this question before posting!

 

This is my first foray into the // world.  I got a new-to-me //e.  I installed a ReActiveMicro PSU before even turning it on.

 

It didn't come with any DOS disks.  I've ordered some on eBay.  But in the meantime I tried writing a few lines of basic and SAVE'ing them to cassette.

 

Forums: 
Apple II

Saturn 128k Card testing without drives?

Submitted by jaymzleutz on January 27, 2024 - 10:24am

Hello, gentlemen!

After consulting Saturn 128k manual, this forum and other sources content I have the following question: is it possible to make a RAM/Card test at the 128k card without any input device where a program can run from?

I could not find any info about it and would really like to check if all the banks of my saturn card are working and if the 3 leds are ok as well.

Is it safe to run a CON command, as shown on reference manual, to set a memory state where the leds would light up, without any risk of changing anything permanently?

Forums: 
Apple II

Pages

Subscribe to Apple II