I am now underway working on implementing an adapted version of the ISA HardMPU card for PCMCIA

Now that will be awesome. Would it be called CardMPU or something else? Keep us posted and good luck.

While I was writing the equation for the gate array I was having some trouble understanding the interrupt mechanism. I am not sure if I am missing something, but can the board only drive the interrupt line during a read on the command port, is that the intended behavior?

bjwil1991 wrote on 2021-03-06, 09:52:

Now that will be awesome. Would it be called CardMPU or something else? Keep us posted and good luck.

That is a nice name! I am planning to stick the dream.fr SAM2695 chip on this board as well, driving audio to the pcmcia speaker pin and an optional output connector, not sure about exposing external midi port, but anybody can adapt this as desired.

I would imagine that is the interrupt acknowledge machanism, that deasserts the IRQ when control port is read.

Currently identifies itself like a Roland SCP-55 so I could use the same drivers / enabler. I am still unclear on this interrupt implementation, I will need to spend more time understanding the MPU-401

It seems to work however, although I do not have any midi device as I ordered the incorrect breakout board for the dream.fr chip, so I just hooked a uart at midi baud rate to look at the messages coming out of pin14 on the atmega.

Impressive stuff. Just realised I saw it in my twitter feed too when LGR commented.

I'm curious about this sentence:

yyzkevin wrote on 2021-03-07, 09:21:

not sure about exposing external midi port, but anybody can adapt this as desired.

Do you mean that by default, your design won't have a MIDI out port to drive an external module?

Pierre32 wrote on 2021-03-08, 08:10:

Impressive stuff. Just realised I saw it in my twitter feed too when LGR commented. […]
Show full quote

Impressive stuff. Just realised I saw it in my twitter feed too when LGR commented.

I'm curious about this sentence:

yyzkevin wrote on 2021-03-07, 09:21:

not sure about exposing external midi port, but anybody can adapt this as desired.

Do you mean that by default, your design won't have a MIDI out port to drive an external module?

My current goal is to implement the hardware MPU-401 (seems to be working) and place a dream.fr SAM2695 chip onboard which is a full general midi synth, and the audio output would be sent to to the internal laptop speaker through the pcmcia slot (poor quality of course). Maybe as well an audio jack of sorts that would disable that. I have the dream midi chips but I cant find a 0.4mm qfn breakout board for them! I may end up just gambling and sending off a design to pcbway and hope it works.

Some options would be to have the external midi connector and a method to disable the onboard midi synth. I really know next to nothing about Midi so I am just trying to figure this out as I go!

impressive work so far, kudos!
doing this on the pcmcia space constraints add another layer of difficulty on top!

yyzkevin wrote on 2021-03-08, 08:31:

Pierre32 wrote on 2021-03-08, 08:10:

Impressive stuff. Just realised I saw it in my twitter feed too when LGR commented. […]
Show full quote

Impressive stuff. Just realised I saw it in my twitter feed too when LGR commented.

I'm curious about this sentence:

yyzkevin wrote on 2021-03-07, 09:21:

not sure about exposing external midi port, but anybody can adapt this as desired.

Do you mean that by default, your design won't have a MIDI out port to drive an external module?

My current goal is to implement the hardware MPU-401 (seems to be working) and place a dream.fr SAM2695 chip onboard which is a full general midi synth, and the audio output would be sent to to the internal laptop speaker through the pcmcia slot (poor quality of course). Maybe as well an audio jack of sorts that would disable that. I have the dream midi chips but I cant find a 0.4mm qfn breakout board for them! I may end up just gambling and sending off a design to pcbway and hope it works.

Some options would be to have the external midi connector and a method to disable the onboard midi synth. I really know next to nothing about Midi so I am just trying to figure this out as I go!

All of which sounds awesome! But I ask because, given the history and original intent of SoftMPU/HardMPU, it would seem a shame to have all this magic packed into a card and not be able to drive an MT-32 with it.

yyzkevin wrote on 2021-03-08, 08:31:

Some options would be to have the external midi connector and a method to disable the onboard midi synth. I really know next to nothing about Midi so I am just trying to figure this out as I go!

There are 3,5mm to MIDI cables. Maybe it will be possible to add another connector for it?

Detailed article:
https://www.midi.org/midi-articles/updated-ho … -pin-din-cables

I guess I thought because it was for a laptop nobody wanted external midi. I think in this case we would go with a "regular" card connector, and can have some options for various audio as well as the midi and potentially analog gameport.

the issue with those connectors, I am able to buy the framekits out of distribution in any qty I want but the connectors are non-stock so I have to buy I am not sure maybe 60 at a time. Up until now I have not used connectors

https://www.digikey.ca/short/w8q0jf8h
https://www.digikey.ca/short/w49p2tw9
https://www.digikey.ca/short/pzf8275h

Basically, we would need to find framekit, receptacle and plug that are available. I would much rather this not be a fixed cable as I did have the use case in mind where it is strictly playing out of the laptop speaker.

I agree that maintaining the fully internal use case is important. A very neat scenario and will probably have the broadest appeal.

I didn't set out to throw an MT-32 shaped spanner in the works, but I dig that you're looking into it. The Orpheus and PC MIDI cards use these connectors for MIDI - I wonder if Keropi can give any insight on their sources.

adding the external midi connection does not create a technical issue beyond the mechanical aspect. I could use two pins on the connector to detect when external dongle was plugged in and disable the onboard synth, or maybe I make a utility to disable it, all of that is easy just have to decide what is best.

I wondered though, given that laptops are a decent choice for retro dos computing/gaming (aren't they?) why does nobody produce any new pcmcia cards, is it due to lack of demand? not wanting to deal with the space restriction? not wanting to deal with/understand the pcmcia side of things? Most palmtops and many laptops don't have a printer port without a dock, some are also XT/286 etc and cannot run SoftMPU.

yyzkevin wrote on 2021-03-08, 22:05:

Basically, we would need to find framekit, receptacle and plug that are available. I would much rather this not be a fixed cable as I did have the use case in mind where it is strictly playing out of the laptop speaker.

Here's what I found in terms of connectors.
Digikey has 49 of these plugs https://www.digikey.com/en/products/detail/hi … 5PAA-50/3978369
Mouser has a stock of covers for them https://www.mouser.com/ProductDetail/Hirose-C … P%2FYSek6qd8%3D
And expects 120 of receptacle connectors in April https://www.mouser.com/ProductDetail/Hirose-C … WvkTg40eA%3D%3D

Bondi wrote on 2021-03-09, 08:38:

Here's what I found in terms of connectors. Digikey has 49 of these plugs https://www.digikey.com/en/products/detail/hi … 5PAA-5 […]
Show full quote

yyzkevin wrote on 2021-03-08, 22:05:

Basically, we would need to find framekit, receptacle and plug that are available. I would much rather this not be a fixed cable as I did have the use case in mind where it is strictly playing out of the laptop speaker.

Here's what I found in terms of connectors.
Digikey has 49 of these plugs https://www.digikey.com/en/products/detail/hi … 5PAA-50/3978369
Mouser has a stock of covers for them https://www.mouser.com/ProductDetail/Hirose-C … P%2FYSek6qd8%3D
And expects 120 of receptacle connectors in April https://www.mouser.com/ProductDetail/Hirose-C … WvkTg40eA%3D%3D

thanks, quite helpful! if we can actually get those receptacle connectors this becomes a lot easier. I wonder were they ordered in for general inventory or already assigned to somebody. Pin pitch is okay for me to work by hand so I can continue the development and just attach a cable to the pads.

this is terrible video quality, but just showing the mpu-401 running in an HP200LX. I still do not have a synth working yet so you have to use your imagination when watching that led flash midi messages.
https://www.youtube.com/watch?v=AhXUn6RuWj0

yyzkevin wrote on 2021-03-09, 08:32:

I wondered though, given that laptops are a decent choice for retro dos computing/gaming (aren't they?) why does nobody produce any new pcmcia cards, is it due to lack of demand? not wanting to deal with the space restriction? not wanting to deal with/understand the pcmcia side of things? Most palmtops and many laptops don't have a printer port without a dock, some are also XT/286 etc and cannot run SoftMPU.

The demand is there. Just take a look at the price of SCP-55 that's being sold on Ebay right now, and the one sold recently.
As I was told by Serge the the physical dimensionsion of a pcmcia card is a real challenge.

yyzkevin wrote on 2021-03-09, 08:51:

thanks, quite helpful! if we can actually get those receptacle connectors this becomes a lot easier. I wonder were they ordered in for general inventory or already assigned to somebody. Pin pitch is okay for me to work by hand so I can continue the development and just attach a cable to the pads.

The receptacle connectors are indeed the key. As the 25 pin plugs are very common, many cards used them. And it would be probably easier to find a used one and customize it to be used with your card. Same for 32 pin conectors.

The 32 pin receptacles are available https://www.mouser.com/ProductDetail/Hirose-C … YlJph3xjw%3D%3D
But the plugs are non-stock.

this is terrible video quality, but just showing the mpu-401 running in an HP200LX. I still do not have a synth working yet so you have to use your imagination when watching that led flash midi messages.
https://www.youtube.com/watch?v=AhXUn6RuWj0

Cool! Both thumbs up!!

So I have run into an issue of sorts.

The SCP55 enabler for dos from Roland allocates 330h and IRQ5 for the MPU-401 interface. The enabler that has been written for the HP100/200LX sets 330h and IRQ3 I believe, which I attempted modifying to use IRQ2/9 but I do not understand how to deal with the conflict with the keyboard, so this is beyond my abilities, keyboard becomes unusable when I put the MPU on IRQ2

So, in light of the fact that this card, with my abilities, will only support IRQ5 (or anything else you can get the host to configure for the SCP-55), is this still a useful card to pursue?

My thought is, if you are trying to play old games it is on an old laptop that cannot run softmpu, but if the old games require irq 2/9 then this does not make sense.

confirmation there is some midi output, terrible though as all I currently have is this VLSI chip
https://www.youtube.com/watch?v=xRbkijJc5F8

yyzkevin wrote on 2021-03-12, 07:10:

So, in light of the fact that this card, with my abilities, will only support IRQ5 (or anything else you can get the host to configure for the SCP-55), is this still a useful card to pursue?

Why not? Most people are going to use it on a regular netebooks, not the 200lx, IMHO.
Also SoftMPU works with real mode games only. So having even jsut the hardware MPU-401 port is a big deal.

I found a schematic from 1987 of a roland ISA card for interfacing the MPU-401 and it showed the interrupt connection how I thought it should be so I implemented that change and I was also able to assign my card 330h and IRQ9 on a normal laptop with regular card services and I am able to open the sierra games LSL2, LSL3 etc but I am not sure if they are okay or not because the midi music is pretty gibberish, but I assume that is because it is a ridiculous VSLI 1052 chip taking what is meant for an MT-32

I am trying to get my hands on an MT-32 to do some testing before finalizing the pcb.