Recent content by MattPilz

Excellent! I've found the Aquarius board to be really fragile when desoldering chips and it's easy to lift pads or traces. I'd second the composite mod by Sean/1Stage. He offers a through-hole and surface mount version and it works well. There's one screw in particular that is very easy to...

A quick sale, $299 buy-it-now for all of that including Expander 1. Here's an example of what the APL/S scripting would look like on VideoBrain. And this is what the actual cartridge looked like, at least in some iteration of it from 1981. So if the ROM dumps make their way public, it...

Hi, I saw your post on AA and replied there, but am sharing here as well for the sake of discovery. When it's powered on (with volume on your TV up) press RETURN and check if you hear a BEEP and if anything visually changes on the screen. Then press CTRL + G to listen for another beep. If you...

An old thread, but for preservation sakes here is the recent eBay listing photos of a sold APL/S cartridge and manual. After all these years it actually has been floating around somewhere out there! And hopefully not the only one. Still wishing to eventually see the ROMs dumped and complete...

I can't remember if I found or adjusted J4 as I also still don't fully understand the resident RAM part or purposes. It does use a HD146818P for "Real-time Clock Plus RAM" (which I read in datasheet is 50 bytes low-power static RAM). And what SAMs identifies as M16010C RAM, seen below. I can't...

Thanks, I did actually buy a copy of the SAMs QX-10 schematic (digital) toward the very tail end of my troubleshooting when I discovered such a thing existed! I printed it out but haven't gone through it too carefully. I bet you're right and it's an error somewhere up the line from the on-board...

Thank you both! I had set this project aside and at some point came upon a second QX-10 that had a bad video sub-board but I was able to get it running. However, I'm curious yet to fix the original. I did ultimately socket the bank 0 ones and had hope that would resolve it, since I found a...

I've been having a go troubleshooting an Epson QX-10 but know there are some here far more experienced with this system than I am. The problem is immediately on boot it goes into an endless beep with "Diagnostic Code: 0002" shown. It does not reach the point of reading disks or anything else...

Finally, after months of limited time and testing a lot of random things, I managed to fix both of my TI-99/4As to perfect operation! In the process I went down the rabbit hole of understanding production revisions and became much more familiar with the hardware. My first experience with the...

I recently got a Model I (with Level II ROM daughter board, lowercase mod and some other curiosities I'll describe below) that was badly busted and banged up in transit. The exterior is problematic but most of the internals seem in-tact from my initial review, aside from the plastic risers and...