Search found 95 matches

by keli
Thu Dec 21, 2017 2:51 pm
Forum: HARDWARE DISCUSSIONS
Topic: MNT VA2000 graphics card in a Mega ST
Replies: 11
Views: 3144

Re: MNT VA2000 graphics card in a Mega ST

Update as of 12/21/2017: I started a new HDL project from scratch instead of trying to understand all of the original VA2000 sources, as almost all of the logic was in the top file... most of it in a huge state machine. Instead I've divided everything into small modules talking to each other using t...
by keli
Thu Dec 07, 2017 3:53 pm
Forum: HARDWARE DISCUSSIONS
Topic: MNT VA2000 graphics card in a Mega ST
Replies: 11
Views: 3144

Re: MNT VA2000 graphics card in a Mega ST

A small status update. I managed to solder the sockets on to the adapter board and have done some testing. First the bad news: The bidirectional voltage converters/buffers on the VA2000 all have their /OE pins hardwired to ground. This means that while the FPGA is powering up, its outputs have an un...
by keli
Wed Nov 29, 2017 6:25 pm
Forum: HARDWARE DISCUSSIONS
Topic: MNT VA2000 graphics card in a Mega ST
Replies: 11
Views: 3144

Re: MNT VA2000 graphics card in a Mega ST

I just received the PCB for my adapter. I used ALLPCB and ordered 5 copies for USD 16.00. (Actually received 7) I have all the components, so as soon as I have a few spare clock cycles, I will have to start soldering. pcb 1.jpg I used the footprint for a straight DIN connector for the MegaBus, but a...
by keli
Mon Nov 27, 2017 1:57 pm
Forum: HARDWARE DISCUSSIONS
Topic: Project: HDMI/DVI out for STFM
Replies: 514
Views: 60224

Re: Project: HDMI/DVI out for STFM

AFAIK there is only the palette register, colour changes AFAIK can't reset anything else full screen demos wouldn't work. Possible resolution changes could trigger a internal reset... but again it also would double up that the shifter doesn't output any data for a while and blanking is active for a...
by keli
Thu Nov 23, 2017 8:36 am
Forum: CHAT FORUM
Topic: How Japanese students multiply
Replies: 4
Views: 1078

Re: How Japanese students multiply

Here's a good explanation of how it works: https://tapintoteenminds.com/japanese-multiplication/
by keli
Mon Nov 20, 2017 7:32 pm
Forum: HARDWARE DISCUSSIONS
Topic: D68000 FPGA core ?
Replies: 6
Views: 1467

Re: D68000 FPGA core ?

There is also the LGPL licensed TG68 open core. https://opencores.org/project,tg68
by keli
Mon Nov 20, 2017 6:26 pm
Forum: HARDWARE DISCUSSIONS
Topic: MNT VA2000 graphics card in a Mega ST
Replies: 11
Views: 3144

Re: MNT VA2000 graphics card in a Mega ST

Looks interesting! What are the actual specs for the card ? Though assume there will also need to be drivers done for the ST.. It's based on the MiniSpartan6+ and he originally just made an adapter board with just the level converters and sockets for that board. It has later evolved into a board on...
by keli
Mon Nov 20, 2017 5:28 pm
Forum: HARDWARE DISCUSSIONS
Topic: MNT VA2000 graphics card in a Mega ST
Replies: 11
Views: 3144

MNT VA2000 graphics card in a Mega ST

I recently found this open source FPGA graphics card made for the Amiga ZORRO II/III expansion bus . After studying the inner workings of the ZORRO II expansion bus, I noticed it was pretty close to the bare m68000 CPU bus. Feeling brave, I ordered a card from his web shop and now I have a shiny Spa...
by keli
Fri Nov 03, 2017 7:19 am
Forum: HARDWARE DISCUSSIONS
Topic: Project: HDMI/DVI out for STFM
Replies: 514
Views: 60224

Re: Project: HDMI/DVI out for STFM

Then TOS writes the appropriate video mode value directly into the shifter's video mode register without caching it in a RAM variable The value is in fact cached in RAM at 0x00044C (sshiftmd system variable). Some interrupt handler or handlers reads the shifter's video mode register directly and wr...
by keli
Wed Nov 01, 2017 11:43 am
Forum: HARDWARE DISCUSSIONS
Topic: ST SHIFTER operation ?
Replies: 94
Views: 14681

Re: ST SHIFTER operation ?

Hi Exxos, the shifter gets A1-A5 rather than A0-A4, so the odd addresses are already excluded. The shifter does get A1-5 (its just internal bus names which are called 0-4). I think I confused 8bit and 16 here, as each address should be 16bit AFAIK. So I should decode all 32 16bit address lines for ...

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