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I have another Apple IIGS logic board, ROM01. Very clean board - no corrosion on the top or bottom. None of the chips appear to have any corrosion. Battery has been removed. No cards installed. All power lines are there. No short-to-ground going on. Power supply is good. 65C816 is a good CPU...

First off, are there any step-by-step guides to troubleshooting a IIGS logic board in a somewhat dead state? I have a logic board, ROM01, part number is 607-0713D. With no cards installed and no keyboard connected, I power it on and it displays the checkerboard pattern, with white and black...

Those four keys you named off are on the same Y-axis, which is mapped to pin 4 on the ribbon connection. If your continuity testing is successful on this line, then it may be the keyboard controller. In that case, pull out the keyboard controller chip and inspect both the pins and the 40-pin...

I'm hoping I don't have to create a library file for the Apple-1 expansion slot and edge connector from scratch. Does this library exist for Eagle or KiCAD?

Curious to learn of anyone who attempted - successful or not - to build an Apple II from scratch, using the "rev 0" Chinese knock-offs of Willegal's logic board design? I bought one just to have for show - even had the logic board laminated at FedEx/Kinko's. I may buy another one if these boards...

Mid-June 2020 - an Apple II s/n A2S1-13176 was sold for $1,5000... https://www.ebay.com/itm/Rare-Apple-II-Computer-820-0001-03-REV-3-w-monitor-drives-stand-cards-docs-/274391949573 Looks like a good clean sale. The computer had a rev 3 logic board, silver-colored power supply, and Datanetics...

Aloha! I recently received a Unitron U-2200 logic board. What's missing are the ROMs, including the Boot ROM and the character ROM. I do have the ROMs for the U-2000, but in my research the two boards are different to the point where the U-2200 auto boots into CP/M by default, which is the...

When I was in high school (early 1980s,) I took this very joystick of discussion and basically copied it. I was taking metal shop at the time, so I was able to fabricate my own case. My dad was flying radio control airplanes at the time, and had spare pots and joysticks on hand, taken from RC...

Aloha!!! I can't seem to find a solution to the following problem... I'm using SBASM 3.0 cross-assembler, assembling in 6502 mode. It assembles the code just fine. The problem is that I'm trying to take the resulting raw object file, copy it to a DOS 3.3 disk using CiderPress, and change the...

https://www.ebay.com/itm/Original-Vintage-Apple-II-1982-EXTENDED-80-Column-Text-Card-Supplement/273963609838 Extremely rare "supplement" for the Apple 80-column card. When this supplement is installed, unicorns will come flying out of your computer. Buy this before it disappears!

Alright! Better late then never..... Found out the function of S2 on the Apple II encoder board. With a SPDT switch installed, the only thing it really does is disable the SHIFT key from functioning for the "P", "N" and "M" keys. Normally, SHIFT-"N" generates the "^" character, "P" generates...

I have only the bottom with the original power supply #000337. Attached is the labeling on the bottom. I'm looking to re-build this computer, but would like to know which logic board and keyboard would best match based on what appears on the labeling? Version of logic board would be something...

I've attached a zip file containing a MP3 file of the speaker audio. This forum doesn't support audio files. The problem I'm having is not just the audio when I turn the computer on, but also when I hit CTRL-RESET. On power-on, the speaker doesn't beep normally. The speaker instead has this...

Not much from which to work. First off, is it a Disk II or a 5.25 drive?

Curious question.... Several Apple II drive manufacturers used the same Shugart SA390 mechanism as Apple's Disk II. I've listed below disk drive analog cards from the following companies: Apple, Franklin, Micro-Sci, Trak and Unitron. Apple Franklin Micro-Sci Trak Unitron Just through...

The function of S2 has something to do with pins 6, 7, 9 and 10 data output pins on the encoder chip. Normally, pins 9 and 10 connect to inverters (74LS04 on the encoder PCB,) which is then fed to a 74LS257 (B7 on the motherboard) The output of that chip is then fed to the DP8304 transceiver...

As if I needed a challenge.... I have an Apple II clone logic board. It is one of your average logic boards that uses a ROM card/slot, 6502 and Z80 processors onboard, and 64KB RAM onboard (eight 4164 modules.) When it boots, it displays "ABC" where "APPLE ][" would normally appear. Few...

Hey, guys! I was given an HP Pavililion. It has an ASUS A7N8X-LA motherboard, with 512KB DIMM and the original hard drive and OS. First thing I did was restore the original Windows XP operating system (it also re-formatted the drive to NTFS prior to restoring OS) using the F10 option. So the...

Aloha! I have an Apple Lisa II 2/10 computer I've owned for the last 25 years. It works, but with a few exceptions... It has the 10MB widget hard drive, but it is not functional. The computer can boot up if I connect my Mac Floppy Emu to it. The floppy drive is still in it, but I doubt it...

This is what I meant by a splitter cable. Is it just wires in series? Or, is there some discrete components inside?