The Motorola 68000 support in the Retro-uC has been finished. More details can be found in my blog post; the release can be found on gitlab. If there people who fancy porting the Retro-uC to another FPGA, don't hesitate to contact me.
I've gathered the various pieces of the design as follows: RETRO-EP4CE15 Card RETRO-EP4CE15 CardQMTECH EP4CE15 FPGA Card M68000 CPU TG68K_2013 VHDL CoreTested to run at 25 MHz Monitor ROM TSBUG2 MonitorTUTOR Monitor Internal SRAM 32KB16Kx16 Video Display...
British Telecommunications Engineering Volume 6 Part 4 page 284 68000 STEbus Processor A new high-performance CPU card from British Telecom Microprocessor Systems offers designers exceptional processing power on an extremely cost-effective bus — STE....
OK, I guess I'll do another log since all I have to do is copy and paste some stuff from a reddit post: https://www.reddit.com/r/m68k/comments/63ov3e/fast_68000_block_memory_move_routine_comparison/simple memory move routines based around MOVE and DBRA...
I have implemented a very simple exception handler so that I can figure out what is causing the machine to fault. The exception handler is telling me that the issue is an invalid instruction. It turns out, I forgot to add -march=68000 -mcpu=68000 to...
68000 CPU on a mid-90's board that may be from specialized navigation/training(?) equipment; a giant ASIC contains many mysteries.https://www.flickr.com/photos/147639706@N02/albums/72177720314646603/
The Motorola MC68000 Educational Computer Board (MEX68KECB) User Manual has the command set for TUTOR in Section 3.6. Here's a snapshot of the commands:
After a few days of messing around with the FPGA top entity, I got it running and was rewarded with the TS2BUG prompt on the VDU. Lesson LearnedFPGA implementations of CPUs rarely match the pins of the original part. They are typically poorly documented...
I wanted to run Jeff Trantor's build of the TUTOR monitor since it has a lot more features than the TS2BUG. The User Manual for the MEX68KECB details the commands for TUTOR. It requires more ROM resources than the TS2BUG monitor design used. The...
Finally got a stable working FPU which is compatible with printf. I was surprised by the amount of maths used to print a floating point number. I have new wrapper functions now which replace the 68000 FP emulation code provided with the gcc compiler....
After I got mine hands on some Homebrew Z80 system, and watching some famous videos about 6502 I understood that I want to build my own thing. The decision to make something based on 68000 came from unrealised childhood desire to get Sega Mega Drive...
Creating a log just to chart my progress (or lack thereof).I've got a copy of 68000 Microcomputer Systems: Designing and Troubleshooting and have read through the early parts a few times, as well as reading up on what others have done before. My interest...
I've got a bit further analysing the equations than the files uploaded on the 13th March, but for some reason I am unable to upload files as of now.The 68008 board PAL chips provide good hints about the logic. The 68000 logic seems to be complicated...
I've found exactly one example of schematics of a machine that used the 451 at https://archive.org/details/bitsavers_compuproA1nualNov83_1763479/page/n7/mode/2up Unisoft was a company in the 80's that ran around porting UNIX to various things, and...