exxos's Atari, Amiga & retro forum

I've spent a good bit of time on this lately and its now off to get built. A huge number of fixes are down to things that @GadgetUK164 found during his build of the Rev1. Other things include: -

1. Fixing the sound circuit fixes to use an op amp and to buffer the cart sound.
2. fixing the joystick orientation,
3. A bunch of things on the PCB design that were spotted by my friend Madhacker (Acid traps, DRC improvements).
4. The placement of mount holes helped by @go0se
5. Allowing the ARM to generate sound (if the ARM model permits. Potentially SCC in the future on higher end ARMs.
6. Fixing the PPI_SND for the keyboard click.
7. Single jumper to switch support for the VDP versions (detected by the CPLD and pins pulled or floated appropriately).
8. Switchable inline 330R on the Sync line (Jumpered)
9. Dip switches for ROM selection (up to 4 different ROM sets - I imagine this can be used to switch between 50/60hz and MSX2/MSX2+ ROMS).
10. breakout pads added to allow a Jamma break out board in the future.

Oh and i fixed the most important bug... a typo on the Silkscreen. BangoGuyOllie has been changed to BanjoGuyOllie..

Probably other fixes i've forgotten.

Congratulations! Awesome achievement!

:bravo:

Well done !

Well done.

Three words to say…..

Gimme gimme gimme

Always been interested in MSX, is this based on MSX1 or MSX2? Are the custom chips able to be acquired from somewhere?

Steve wrote: 15 Feb 2023 16:55 Always been interested in MSX, is this based on MSX1 or MSX2? Are the custom chips able to be acquired from somewhere?

If you have a look, it can be either/both.

It's not that I didn't look, I do see it supports both VDP's. But I don't know MSX architecture well enough to know if that is simply the only difference.

Steve wrote: 15 Feb 2023 18:07 It's not that I didn't look, I do see it supports both VDP's. But I don't know MSX architecture well enough to know if that is simply the only difference.

There is an RTC and battery backed up ram which we wont be bothering with in the MSX2 standard. The RTC is required but will be faked to a hard coded date unless someone is really in the mood to find a way to squeeze a battery on there.

The VDP options here are MSX2 or MSX2+. But by using the correct ROM you could get MSX1/MSX2/MSX2+

Very awesome, thanks @terriblefire :)

terriblefire wrote: 15 Feb 2023 20:47 There is an RTC and battery backed up ram which we wont be bothering with in the MSX2 standard. The RTC is required but will be faked to a hard coded date unless someone is really in the mood to find a way to squeeze a battery on there.

I s'pose that a "starting date/time" plus then running the clock whilst the machine powered on if a good work-around. Maybe in future some sort of serial net device could be hacked on to do an NTP date, possibly using an add-on ROM image.

Anyway, unless someone is going to use a disk drive and productivity software I'm not sure anyone will notice. :-)