Recent content by otacon14112

I'm using a VT82C42N keyboard controller for an 8088 computer I'm building, but it generates continuous interrupts. I removed the instruction that sends AAh to the controller, but it still generates infinite interrupts. I programmed the ISR to print the hexadecimal byte that's put on the data...

Years ago when I worked for an office supply store, a customer came in and said that he was giving away an old computer, which was sitting right outside his garage. Well, knowing me, I went there and got it. It's a Gateway 2000 386/33. It's never worked as long as I've had it; I always meant to...

I slowly keep adding more functionality to my single board computer. The most recent subroutine I wrote converts AL from binary to two ASCII characters representing the two hexadecimal digits of AL. However, when I try to print the newly-converted ASCII characters, my PrintChar subroutine...

I have a 1.0 GHz Pentium iii Compaq Evo N600 laptop that works perfectly. It has 1 GB of RAM and a DVD-ROM. The battery still charges, but only lasts for about 30 - 45 minutes before it runs out. I love this thing. It just keeps working and working. I have a new gaming computer I built, and a...

Now that I got my 20x4 LCD display working on my 8088 homebrew computer, I'm playing around with strings. I'm trying to learn proper string manipulation, and so I thought I'd start with trying to find the length of a string. It sounds simple, especially since there is scasb. But I'm doing...

I've had this for almost ten years, and it's never worked. Finally, one day I opened it up and inspected it. It has a blown component, which I thought, for the longest time, was a diode. It also has two loose wires. It wasn't until today I confirmed it was a capacitor from looking at 600xl_1.png...

How do you guys debug 8088 programs? I can't get gdb to work with 8088 programs. Gdb works with elf executables, but I'm having great difficulty trying to to debug my 8088 binary programs. They were designed to fit onto a 2k ROM chip, and they won't run in DOSBox, or any other emulator because...

Hey guys, it's been a couple years since I messed with my 8088 project. I took a break from it because I got frustrated with not being able to correct some problems. Anyway, I decided to start over from scratch a little over a week ago. It's gone good so far. I just added 4 dual-digit...

Hi guys, I've been trying to figure out what's wrong for over a year. I can get this screen to work P E R F E C T L Y on a PIC microcontroller, PIC16F690 to be exact. I'm trying to use an 8255 Programmable Peripheral Interface and output the data through its ports. I've tried 4-bit mode on port...

Hi guys, I've been working on an 8088 board system on and off for about a year, and one thing that I can't figure out after all this time is why the system seems to work sometimes, and not work other times when I power it up. I've tried using different-valued capacitors, and snooping around with...

I have a blue background with white character 20x4 AMC2004A. From what I've read, it's based on the HD44780U chip. I've read tutorial after tutorial, and the datasheet for both the AMC2004A and the HD44780U. I really hate to ask this here. It's basically admitting defeat. But I've spent dozens...

Hello everyone, I am getting into messing around with computer design, and I've been following The 8088 Project Book by Robert Grossblatt. I have read and studied his text and schematics very closely and carefully, and I have learned a lot so far. I'm really pleased with the book. It's helped...