very simple 68k tini board - Page 1
Forum section: electronics / general

author: DiTBho
author_rank: Super Contributor
timestamp: August 22, 2024, 12:59:14 pm
content: I'll point it out to you. Maybe someone will be interested.Seehere(kind of Wikipedia)For glue logic it only uses two PALs to program with a Windows software (free download).Feally very simple, I didn't understand if there are PCB gerbers and/or a KiCAD or EagleCAD projectI haven't yet investigated too much, I found it while looking for information on the toolchain for m68k to integrate with a libc {uclibc, musl, ...}.And found that, among the various entries in Wikipedia, there is a link to a github repo,here, for building a complete toolchain, including not only gcc but also a second C compiler Vbcc!!!Enjoy it, happy hacking

author: pqass
author_rank: Super Contributor
timestamp: August 22, 2024, 03:51:47 pm
content: I'm working on my own 68k8 (currently on a breadboard). I was able to "get to blinky" remarkably fast given that I'm new to 68k hardware design and assembly. Many thanks toJeff Tranter's blog, his youtube video, and the Alan Clements book.Thankfully I haven't had to build gcc; just installed (on Linux):binutils-m68k-linux-gnu-0:2.37-3.fc35.x86_64gcc-m68k-linux-gnu-0:11.2.1-1.fc35.x86_64And, for a minimal C environment, seehere; specifically the "standalone" directory.For my initial LCD "hello world" program, I haven't even had to compile the minimalist libmetal library yet; just copied over a couple of .S files.

author: DiTBho
author_rank: Super Contributor
timestamp: August 22, 2024, 07:47:50 pm
content: Quote from: pqass on August 22, 2024, 03:51:47 pmSee, I built a builder to build { binutils, gcc } toolchains, not only for 68k but also for 68hc11, and, among the dead things, also 88k.it works very well, but i hacked gcc very deeply. some patches i could have avoided. this is what i understand looking at toolchain builder like the one used in this projectFor me this project has much more importance for that Makefile that you find in the second link that I indicated.It shows some interesting tricks.-Then I really liked the approach to pal, with everything you need, and it's really little

author: DiTBho
author_rank: Super Contributor
timestamp: August 30, 2024, 12:35:39 pm
content: Is anyone interested in making the PCB for this tini project?

author: amymcneil
author_rank: Contributor
timestamp: October 15, 2024, 02:51:09 am
content: I'm interested enough in a board to be in the middle of getting the schematic into Diptrace so I can layout a board.I am willing to have more than I need made and offer them for sale to others at cost + 10% plus postage. They're small boards, shouldn't cost much, probably less than $10 USD.I'll repost when I finish the layout and am ready to send to fab.

author: amymcneil
author_rank: Contributor
timestamp: October 15, 2024, 03:11:27 am
content: I meant to add - if someone (OP?) has boards available, I would like to buy one. Will save me some work and I can get on to hacking MC68000 assembly sooner!Thanks!

author: woofy
author_rank: Frequent Contributor
timestamp: October 15, 2024, 09:18:59 am
content: I built this this one a while back:https://hackaday.io/project/177988-68k-mbc-a-3-ics-68008-homebrew-computerI still have a couple of PCB's with red resist instead of blue. If anyone wants one, let me know - free in the UK.

author: SiliconWizard
author_rank: Super Contributor
timestamp: October 15, 2024, 09:41:43 am
content: As far as a 68008-based machine, I have a Sinclair QL that I repaired, fully functional, and maxed it to 768KB RAM. Fun stuff.

author: DiTBho
author_rank: Super Contributor
timestamp: October 29, 2024, 03:45:28 pm
content: Quote from: woofy on October 15, 2024, 09:18:59 amThe author of MBC has filled *every forum* - he says - just to test the interest - and I don't like that, just like I don't like at all the approach he used: using a RISC MPU much faster than the CISC CPU to emulate the peripherals and for the glue-logic.

author: DiTBho
author_rank: Super Contributor
timestamp: October 29, 2024, 03:54:16 pm
content: Quote from: amymcneil on October 15, 2024, 02:51:09 amThat's nice! ThanksAdd +1 for me!I'm currently pretty busy with a MIPS-R3K development board made in 1989.The hw was faulty, but I fixed it. then I abandoned it for months, in a corner.I pick it up again every now and then, but this time I'd like to at least finish the "monitor".(able to tftpload things from the net ... because the serial is really too slow ... 9600bps, can't be changed, d'oh)It's written in pure assembly, it's not that hard, except cache ... which is very evil.Just ... when I estimate 4 hours x 2/WE... that's never enough

author: amymcneil
author_rank: Contributor
timestamp: December 22, 2024, 04:07:41 am
content: Board design is completed. I tried to be as faithful to the original design of DiTBho's SIMPLE-68008 as I could.There are a few differences though.1) The board is a 4 layer design, inner layers are VCC and GND.2) The memory configuration jumpers are now 3 pin headers on the top side of the board.3) The power input is a screw terminal block rather than a header.All component designators are the same, the component locations are in approximately the same locations as the original design. The I/O headers have the same pin out. Board size is 3.75" square. Mounting holes are 0.156 dia through hole with 0.250 isolated pad, the holes are 0.20 from each edge, 3.35 on centers.I've attached PDFs of the schematic and the board layout. I should be sending the job out in a day or two, to have a few boards made to test the design and confirm that I haven't made any mistakes in my transcription of the original design. Chips are sitting on the shelf waiting for boards. Comments and suggestions are welcome.

author: DiTBho
author_rank: Super Contributor
timestamp: January 01, 2025, 10:50:13 am
content: Looks great!!!

author: amymcneil
author_rank: Contributor
timestamp: January 07, 2025, 09:07:28 pm
content: Boards arrived. I need to order a few parts like sockets and capacitors. I had fun laying this out, it has been a very long time since I've done a board design that was all through hole components, my projects these days are mostly surface mount. Photo of bare board attached.

author: wilfred
author_rank: Super Contributor
timestamp: January 07, 2025, 10:15:20 pm
content: Quote from: amymcneil on October 15, 2024, 03:11:27 amYou could do that on an emulator, Yeah, I get it, not the same.

author: amymcneil
author_rank: Contributor
timestamp: January 07, 2025, 10:56:40 pm
content: Quote from: wilfred on January 07, 2025, 10:15:20 pmYeah, I know. And it's a lot less money, too.But....I've never enjoyed using architecture emulators for old hardware. Something about the "vibe" if that makes sense. The emulator is just another application on a modern PC, rather than a board that I can point to and say "that's the computer I'm working on". I enjoy the hardware side since my current day job involves writing Linux device drivers and support utilities for proprietary custom hardware implemented in a Xilinx FPGA. While the whole write "code" as a description of the hardware, compiling it and downloading the bit stream to the FPGA is very cool, there isn't the same satisfaction that comes from slaving over a hot soldering iron for a couple hours and holding your finished hardware in your hand(s).I have two other ancient architecture computer projects that I'm collecting parts for. One is a TMS9900 based machine, the other is a PDP8 implemented using the HD 6120 Intersil/Harris chip, along the lines of the Spare Time Gizmos SBC6120. I'll post something about these as I get further along. Both of these are architectures that I've wanted to play with for many years. And both are odd enough to be interesting.

author: DiTBho
author_rank: Super Contributor
timestamp: February 06, 2025, 03:44:46 pm
content: news?