[HN Gopher] I built my own Sega Genesis (Mega Drive) hardware de...
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I built my own Sega Genesis (Mega Drive) hardware dev kit from
scratch
Author : regus
Score : 145 points
Date : 2022-01-21 17:35 UTC (5 hours ago)
(HTM) web link (nestenius.se)
(TXT) w3m dump (nestenius.se)
| rightbyte wrote:
| Heh ... ut: *wait for datapacket to
| be stored att $FF0000 lea $ff0000,a5
|
| I like how he slips in three Swedish spelling "friend words"
| there.
|
| For some reason I have always found a relief in programming and
| mixing in my native tongue randomly. Like, it gives a playlike
| non tryhard touch to it. And the flow is nicer.
| tndata wrote:
| Author here, never anticipated 30 years ago that someone else
| would actually look at the code :-)
| rahen wrote:
| It's great to see some new projects being wire wrapped. It's
| becoming some kind of lost art nowadays.
| tndata wrote:
| Author here, wire-wrapping is like therapy for your mind! like
| solving a sudoku!
| klodolph wrote:
| Fantastic stuff!
|
| There are plenty of modern flashcarts around for various systems,
| but most of them are designed to let you load up a bunch of
| (often pirated) games onto an SD card and play them, and they're
| not very good for development. Nobody wants to build their ROM
| image, copy it to an SD card, swap SD cards around, and then
| reboot the system. (Plenty of people _do_ that, it just sucks.)
|
| It goes to show that making your own cartridge for development is
| not as hard as you might expect.
|
| There are some high-end cartridges out there that let you do
| everything, with both SD cards and USB ports, but it's less
| common to see pure development cartridges, which could be made
| much more cheaply.
| fit2rule wrote:
| codazoda wrote:
| I never really dared to dig into electronics like this. I had a
| nack for breaking things when I did.
|
| As an example, I purchased a Pentium machine back in the day. I
| had a feeling it was running too hot (or maybe I was trying to
| over-clock, I don't recall). But I decided to build a simple PCI
| card. So simple, in fact, that it just had a 12v case fan on it.
| I wired up the +12v pin and the ground pin to the 12v +/- of the
| fan. Then I plugged the PCI board into the PC. It worked! Except,
| it was now the only thing in the PC that worked.
|
| After removing it, the machine no longer worked. I returned it to
| the shop I purchased it from and they informed me that I must
| have had a surge. Everything was destroyed. The CPU, the RAM, the
| Video card, it was all gone.
| tndata wrote:
| The Sega Mega drive was a very robust machine and it did
| survive numerous short-circuits over the years and even today
| it still works!. but yes, I have blown numerous PC-motherboards
| over the years though... I guess that comes with the trade! One
| time I damaged my motherboard that was powered-off by using the
| vacuum cleaner to get rid of the dusts from one of the fans.
| The spinning of the fan resulted in a power-surge that damaged
| my motherboard :-(
| poyu wrote:
| If you want to get into digital electronics and computer
| building, here is a really good series on building your own
| 8-bit computer.
|
| https://www.youtube.com/playlist?list=PLowKtXNTBypGqImE405J2...
| londondev45 wrote:
| A message of appreciation, you sound very cool. I'd love to have
| seen this when I was a young sega mega drive obsessive
| tndata wrote:
| Original blog post author here! Thanks for the kind words!
| InvaderFizz wrote:
| One point I didn't see in the article. How complete was your
| dev kit? Could it actually run commercial games?
| tndata wrote:
| Yes, I could run games and I also wrote some simpler demos
| where I for example could move a player around the screen
| using the joystick. So, it was fully functional.
| nsxwolf wrote:
| What's the sponge for?
| tndata wrote:
| Blog post author here. I used it just to reduce the stress on
| the vertical circuit board.
| jdmoreira wrote:
| I feel like this would be an inferior development experience in
| 2022 compared to this approach:
| https://hackaday.io/project/1507-usb-megadrive-devkit
|
| Which is an fpga in the cartridge that also serves as a gdb stub
| over serial. You can debug with gdb directly on the hardware.
| tndata wrote:
| Original author here, wow! What a cool project!
| [deleted]
| Nexxxeh wrote:
| Really cool read. Am I right in thinking it works like a flash
| cart, but with volatile memory?
| tndata wrote:
| Author of the blog post here. Yes, I basically emulated the
| cartridge rom using static memory. That was the simplest at the
| time.
| hnthrowaway0315 wrote:
| Laughing out loud, cheering and clapping my hands when seeing
| lines such as "As I was on a very tight budget, I decided to
| build my own. How hard could that be?".
|
| I wish I had that intuition and courage to build my own
| birdfeeder back in the day. And of course the author managed to
| do much cooler things.
| tndata wrote:
| Original blog post author here! Thanks! :-) Perhaps its not to
| late to build that bird feeder :-)
| hnthrowaway0315 wrote:
| Thanks man! Definitely working on that direction. Do you have
| other contemporary projects to show? I'm going to browse
| through your blog this weekend :D
| tndata wrote:
| There are a few other projects I did listed here
| https://nestenius.se/about/ Besides that, my biggest
| project so far is that I created a developer community
| around 1996 called Programmers Heaven that became my main
| living for many years :-)
| tsmarsh wrote:
| I bought Ben Eater's Motorola kit and was overwhelmed, I have a
| whole new respect for folks that can do this.
| tndata wrote:
| Author of the blog post here. Thanks, it was a quite long
| project, but the device have a pretty simple and plain
| architecture that made it easy. Todays consoles are much harder
| to hack, due to multiple layers of encryption and protection.
| jbluepolarbear wrote:
| I had to build an rtos (real-time operating system) for the
| m68k and dealing with how m68k stack pointers work with
| interrupts was really frustrating.
| bluedino wrote:
| I would love to read this kind of article along with all the
| drawings and pictures of a similar kit for the NES, from the
| 1980's
|
| A lot of those early programmers knew electronics they just built
| their own stuff. Crazy compared to your average developer now. A
| lot of guys had to build their own terminals/keyboard etc back
| then (especially the 70's computer clubs). At some point the
| hardware and software kind of split up (lucky for us that didn't
| have any real hardware knowledge)
| tndata wrote:
| Tinkering with hardware back then was much easier because the
| frequency of the devices was pretty low (like 1-8 MHz) and the
| interfaces and system bus was much easier to work with compared
| to todays advanced protocols like (USB, etherhet...)
| hnthrowaway0315 wrote:
| Yup, I guess we can still do it today, for ourselves and for
| our kids, with the right tools. I'm thinking maybe it is not a
| huge amount of effort to build your own hardware back in the
| day because so may people did that. At least they had kits too
| back in the day.
| djmips wrote:
| This is pretty similar to hardware made by Radical Software and
| Accolade for professional development back in the day. Also the
| EA dev hardware was similar but more advanced since it contained
| additional hardware for capturing the bus like a logic analyzer
| might. For the Accolade version it was very similar to this
| design. I worked on the debugger and it was a lot of fun. At the
| time we used the Lattice C compiler and I supported C source
| level debugging including watches that could use a C like parser.
| kingcharles wrote:
| Contemporary with the console, the two kits I had for development
| were SN System's PsyQ, and the one you could buy at a decently
| stocked video games store was the Super Magic Drive which used
| floppies.
|
| https://twitter.com/bigevilboss/status/1142031487317020672
|
| https://segaretro.org/Super_Magic_Drive
| tndata wrote:
| Wow! Nice hardware!
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