Apple II

ROM checksum error

Submitted by tony359 on July 9, 2020 - 5:55am

XPS says that my C0 and E0 ROMs are failing checksum check. Should I be concerned about that? I have an eeprom programmer if that helps - but I would need an UV lamp! :) 

 

Forums: 
Apple II

Horizontal Sync width of Apple II+ NTSC

Submitted by tylak on July 7, 2020 - 11:20pm

Is the Apple II+ horizontal sync width ~8us (for all revisions? ? I think some modern TVs cannot sync'd to the Apple II video because of this.

 

 

 

Forums: 
Apple II

Apple II SchoolBus Cardq

Submitted by 8bit_SchoolBus on July 6, 2020 - 3:22pm

Hi There, 

 

A couple years back I picked up an Apple II "SchoolBus" networking card, made by Apple. According to the promotional literature I was able to find, it looks like it allowed several II/IIe's to be daisy-chained together and share a "server" Apple II and share a Disk II and software. Essentially a teacher could "push" programs to students to work on, similar to teachers using Google Classroom, etc, today. 

Forums: 
Apple II

Strange issue with MECC games - none will start

Submitted by shadmere on July 6, 2020 - 4:03am

I'll admit that I don't really know what I'm doing.  But because of that, I'm not quite sure where to start!

 

I just got an Apple IIe (unenhanced).  Obviously, the first thing I wanted to do was to boot up some old games I remembered from childhood.

 

Every time I try to play a MECC game (Oregon Trail, Odell Lake, Number Munchers, etc), the system loads the title screen with MECC logo and . . . stops.

 

Nothing else happens, no matter what buttons are pressed.

 

Forums: 
Apple II

Help with replacing a capacitor on a //e

Submitted by tony359 on July 5, 2020 - 2:51pm

Hi all,

 

I need to replace C68 on my board - my bad, when prying out the keyboard ROM I didn't realise that the tool was resting on it and I slightly cracked it.

 

C68, according to the schematics, is a 0.1uF capacitor on the +5V. What type of capacitor will be the best one to replace it? Can those glass capacitors still be sourced - to keep the original look - or can I replace it with a plastic capacitor?

 

Thanks!

 

Forums: 
Apple II

Very Interesting Apple //e Diagnostics Card ROMS

Submitted by jwg1962 on July 5, 2020 - 2:30pm

Well, I have sucessfully dumped all the ROMs for the cards below and made a copy of the 077-0130 and 077-0131 ROMs for the diagnostics card I replicated.  

 

And lo and behold, the ROMs (that I didn't fine official Apple Part Numbers for - and now I know why) are logic board testing the Apple ][ and Apple ][+ units.  I didn't dig out an Apple II+ or one of my Apple IIs to see if this card actually works in them, but it looks like it might.    

 

I wanted to post this, but now I am going to go try it and I will post back on this thread what I find out.  

 

Forums: 
Apple II

Finished a couple projects this July 4th weekend...

Submitted by macnoyd on July 5, 2020 - 11:53am

Had a little extra time to finish a couple projects this July 4th weekend, one of them being a Phasor kit sold by Reactive Micro.  Henry does a great job putting this together with all parts well organized and clearly labeled for easy assembly.  I really enjoyed putting this together.

While in the process, I made a few changes (well, improvements in my way of thinking) that I thought I would share with the group.

Changes:

All IC sockets changed to vintage Augat gold machine-pin sockets.

Forums: 
Apple II

Replacement cover for Apple IIe keyboard light

Submitted by joel_graff on July 5, 2020 - 8:46am

I have several Apple IIe machines I'm refurbishing and many of them are missing the keyboard light cover.  I managed to find one replacement, but I need several more and I'm starting to consider manufacturing my own.  It appears the lens cover is acrylic... mabe 10 thousandths of an inch thick... the surface is painted in Apple beige and masked on the underside.I have ideas, but I wondered if anyone else had managed to make good looking replacements...

Forums: 
Apple II

How to make Apple II+ video address linear?

Submitted by tylak on July 4, 2020 - 5:14am

Hi,

I read some book that it only takes a TTL IC  to make the video addresses linear. No further details.

Anyone know how? Will it affect the refresh time? 

Just curtous about it.

 

Forums: 
Apple II

Beltron

Submitted by Timelord on July 3, 2020 - 11:25pm

I recently acquired a Beltron system, and I noticed that it has markings on the keys for BASIC shortcuts. I habe yet to power it up, or to do an diagnostics on it. I am unsure at this time if it is PAL or NTSC. 

 

Do any of you have a Beltron manual, or any docs for it? 

Do any of you have ROM dumps--I plan to make some at some point.

 

Do you lnow the purpose of the 'option' ROM connection?

 

I am likely going to (one day) give it an overall charcoal cololur scheme. 

Forums: 
Apple II

Pages

Subscribe to Apple II