Woohoo, Gateway works now! I had removed some of the code that handles mpu.state.irq_pending thinking it wasn't needed since the IRQ is generated in hardware, but turns out it was necessary anyway.

Great news, congratz! Are there any other open issues?

alexanrs wrote:

Great news, congratz! Are there any other open issues?

I'll be continuing testing of course, but at this point it seems to work flawlessly with every game I can throw at it. Latest code is in git.

ab0tj wrote:

Thanks. This is where the position of the Version and ACK bytes get swapped, correct? I did actually implement this in my version as well, and it can be enabled and disabled with the config utility. I'm curious as to how you implemented enabling or disabling this, as I must have missed that part in the code somewhere.

In SoftMPU I hook the DOS execute BIOS function, hash the executable file name and turn it on for GATE.EXE and off otherwise. Kind of hacky, but it works.

The version byte swap is a workaround for a timing problem rather than a fix, so you might not need it anyway.

bjt wrote:

The version byte swap is a workaround for a timing problem rather than a fix, so you might not need it anyway.

When I was testing yesterday, Legend games seemed to stop playing music after a while without the fix enabled. Right in the middle of a song even. So I guess it is still necessary.

Speaking of MIDI on old machines, I found this video of a sequencer running on a TI-82 calculator. Pretty impressive. Hm, maybe we can port Munt to it. 😀

https://www.youtube.com/watch?v=I6G0CnBSWVk

Has anyone designed a double sided FR4 board for the HardMPU card yet? Are there any missing circuit elements required for MIDI capture, or is that purely a firmware issue?

Unfortunately, I'm not very good at PCB design. I could probably figure it out (might be a good learning opportunity) if someone could provide a short list of guidelines to follow for an application like this.

No, there is not yet a PCB design. The prototype I have been using is on an ISA prototyping board. The hardware for MIDI capture is in the schematic. The software for capture is currently the missing element. Also, the recording hardware has not been tested, although several people that are far smarter than I have looked it over and not raised any objections to that part of the circuit.

Where did you source the proto board? All the ones I've found on Ebay are quite pricey.

I picked up one from this page: http://www.futurlec.com/Protoboards.shtml

The ones on eBay should work too, since this is only an 8-bit card: http://www.ebay.com/itm/1pc-FR4-PCB-board-Dou … =item1e59851533

ab0tj wrote:

I picked up one from this page: http://www.futurlec.com/Protoboards.shtml

The ones on eBay should work too, since this is only an 8-bit card: http://www.ebay.com/itm/1pc-FR4-PCB-board-Dou … =item1e59851533

Perfect! Thank you.

Hi,

any Progress ?
Does Intelligent Mode work ?

Yes, I've been using it with both intelligent mode and uart mode. Seems to work great at this point. There is no pcb or anything yet, just my prototype. I think a few others have built one as well.

I am attempting to make a PCB for HardMPU. I had problems with Eagle so I recreated the schematic in KiCAD. So far I haven't routed it yet. I'm attaching a printout of the current schematic, as well as the schematic itself.

I've tried to keep the same part numbering, labels and pin assignment as the original schematic as much as possible for consistency (but had to deviate in a couple of places due to the differences between Eagle and KiCAD)

(edit) It just occurred to me that it may be useful to add DIN connectors for MIDI in and out on the PCB so you don't have to use a breakout cable, what do you think?

at least MIDI Out 😀

Looks good, yes eagle can give you a hard time... it has some weird glitches..

Cool! Let me know if you order a batch of boards, I'll buy one or two off you.

As for the DIN on the board, I think the reason you don't see them on other MIDI interfaces is that the slot opening in the back of the case is not big enough to accommodate a full size DIN plug.

That's correct. Boards like the MPU401AT and SCC-1 use mini DIN jacks.

Too bad about the DIN connectors. Maybe we can make this a dual-slot board then. 😀

I would appreciate another pair of eyes to go over the schematic and confirm it's correct before I go onto routing. I looked at it 5 times and it appears correct to me, but I've been known to be wrong in the past and miss details.

I say just go with a Soundblaster compatible DB15 jack so everyone can recycle those game port MIDI adapters.

Added DIN connectors for MIDI in, out and a DB15. If the DIN connectors don't fit you may have to mod the case, or leave them unpopulated.

I'm not sure that the DB15 is connected properly, would someone check that? And the rest of the schematic too, please.

I'm attaching again a PDF and the whole project as-is at this stage, zipped. Still not routed. Uses the AV connector footprint library from http://smisioto.no-ip.org/elettronica/kicad/kicad-en.htm ( http://smisioto.no-ip.org/kicad_libs/modules/mod_conn_av.zip )
To add a footprint module in KiCAD you have to open the PCB editor, and in preferences you have the footprint manager that allows you to add external modules. You cannot do it from the schematic editor that only allows to add component libraries, but not footprints.