keith
I’ve been playing with my HP 16700A Logic Analyzer and looking at boot times. Originally the HP 16700A came with an internal SCSI drive, which was still functioning after 15 or 16 years. This SCSI drive was a 4GB...
On building an A500++
Commodore Amiga 500 Plus In the 1980s, Commodore made a newer version of their very popular Amiga 500, called the Amiga 500 Plus. It added a few things, namely newer versions of Kickstart and Workbench — both 2...
Expansion Systems DataFlyer Plus 2.1
Way back in about 1992, I finally had enough money (ok, well, enough credit) to finally expand my Commodore Amiga 500 to how I wanted it. I previously had an A501 memory expansion module and an external floppy drive...
Circle of HOPE 2018 presentation on HomeBrew 68K retro-computing
I delivered a presentation at Hackers On Planet Earth in July 2018 in New York City. For a few different reasons, that presentation was cut short. I decided to rerecord the delivery of the presentation and make it...
Fixed point number formats: might use 16.16
So for my fixed point number format for my 3D project, I’ve come up with a few possibilities : I think a 16.16 number format might work for me. This means I’ll represent the whole portion via one 68k word...
3D Wireframe Rotation dreams…
So I’d really like to be able to rotate 3D objects using this computer. There’s some problems though that make it a little harder than normal. The 68000 doesn’t have any integrated Floating Point...
Adding Yamaha YM2612 support has begun
So after much time talking about it, and doing research, I’ve finally got around to spending some time on adding Yamaha YM2612 support to the badge computer. I created a small verilog driver that read the...
New Indiegogo for Amiga 500 cases
I think everyone could use a brand new sparkly case for their Amiga 500’s. I saw the campaign for the A1200’s last year, and I was jealous. Where is the A500 stuff? Also the keycaps. Your keys are going to...
Updated hope badge computer
Here’s the current image for the Hope Badge Computer, which I really think needs a new name. It’s not quite a badge, although the intention is for it to be portable. Last night, I partially integrated the...
Watching YM2612 communication on Sega Genesis
I did buy a compatible 24-pin DIP clip to make it a little easier, and a little bit more reliable, to hook up the logic analyzer. The YM2612 sits on the Z80 Bus, and so there’s lots of communication not intended...
OT: Century III Mall, not quite a dead mall, but sure heading that way
Century III Mall is an ailing enclosed shopping mall located in the southern Pittsburgh suburb of West Mifflin, Pennsylvania. I lived nearby this mall, and this was definitely “our” mall for kids like me...
Learning the YM2612 with a Sega Genesis Model 1
I’m planning on using the Yamaha YM2612 FM synthesizer chip that has been used in both keyboard synthesizers, but also in the Sega Genesis consoles. The purpose is to add audio capability to my DIY Tablet computer...
Performance of the Hope Badge Computer
I’ve just managed to get some key components working this year, and as a result, the machine is becoming more usable. I wanted to measure the performance of this Frankenstein machine. Ideally, I’d use...
move.w vs move.l: The culprit of my circle problems
If you saw my recent post about malformed circles, you’ll see that I was pulling my hair out. I identified the root cause. It turns out that I was writing 0x00000fff, which caused the pixel I was setting to be...
Graphics Primitives are working, at least mostly.
So we’ve got a frame buffer now which means we can start writing 68K routines to write graphics into it. So here I’m playing around with lines and circles. I’m using a random line drawing routine from...
Frame Buffer and Text Generation now working…
Now that I have the 4MB SRAM board installed, I now have a frame buffer that can keep up with the video bandwidth rate. The resolution and color depth is currently 800 x 480 x 12-bit. The computing shield I’m...
Interesting snippet from FPGA Prototyping by Chu
This is exactly the problem that I’ve been facing for the last couple weeks. I could get the memory tests to pass at 100% if only the CPU was talking with the external SRAM. As soon as I added in my time slot...
SRAM Frame Buffer is now up and running!
Exciting times for the Hope Badge Computer. Tonight, I’ve worked out most of the kinks with interfacing the new SRAM module which you can see in posts below this, to the J68 soft-core CPU. This means that I can...
