Commodore 128 for the MiSTer?

[AmintaMister]

C64 OS has just been released: https://c64os.com/ One of the "recommended" setups is C128, wonder if it would work on this core (baring the fact it's somewhat costly, especially seeing as there is no digital download option).

According to the site, we would need a SD2IEC drive to begin with. Maybe it would work with an SNAC2IEC adapter like this https://ultimatemister.com/product/mister-snac-iec-c64/ and an SD2IEC drive connected, but I have neither of those to test out.

Minimum Hardware Requirements
A Commodore 64 computer
A Joystick
An SD2IEC drive* **

I own both SNAC2IEC adapter and an SD2IEC drive if a test is needed on the core...

[akeley]

According to the site, we would need a SD2IEC drive to begin with.

SC2IEC is listed as the cheapest solution, there are others:

* C64 OS can access all your floppy disk drives, but a mass-storage device with support for native CMD-style subdirectories is required for the system drive. Check out the Commodore 8-Bit Buyer's Guide for a wide range of mass storage devices commercially available for the C64.

** An SD2IEC is the least expensive of the supported storage device families. But, an IDE64 or CMD HD or RamLink can be used in place of an SD2IEC.

Whether these other ones could be emulated in the FPGA I don't know, but you can also install that OS in Vice on a PC, so maybe there could be a way to do it without connecting extra hardware. It also could be that these "CMD-style directories" are already supported.

[eriks5]

Hey I just want to say I've been having fun playing with this core and thank you eriks5 for all your hard work. Now I wonder what else I can do in 80 column mode...

Productivity (including GEOS and CP/M) and Infocom games. LOL

Though I will confess that if he hooks it up to serial the way the C64 is on MiSTer so you can "dial out" to BBSes over telnet, seeing DESterm 128 actually do something again 30 years later would be AWESOME!

Serial is inherited from the C64 core and works. Retro Tech Shed made a YouTube video showing it working: https://www.youtube.com/watch?v=iNJQo9Dt9QM

[eriks5]

Whether these other ones could be emulated in the FPGA I don't know, but you can also install that OS in Vice on a PC, so maybe there could be a way to do it without connecting extra hardware. It also could be that these "CMD-style directories" are already supported.

Mass storage and CMD style directories are not supported in the core

[rhester72]

Serial is inherited from the C64 core and works. Retro Tech Shed made a YouTube video showing it working: https://www.youtube.com/watch?v=iNJQo9Dt9QM

Awesome! I will try this. Thank you!

[djsquare]

It's probably not possible to get that snes controller user port thing to work with the core for Attack of the Petscii Robots? It's one of the only games I mess around in C128 40 column mode. Probably too much work for one game huh?

[ZigZag]

What about a RAM drive?

[djsquare]

It's probably not possible to get that snes controller user port thing to work with the core for Attack of the Petscii Robots? It's one of the only games I mess around in C128 40 column mode. Probably too much work for one game huh?

sorry guys, you can just remap keyboard to joystick controls. I've been a MiSTer user since 2018 and I'm still stupid sometimes

[eriks5]

What about a RAM drive?

REU functionality is inherited from the C64 core and works as far as I know. It provides a ramdisk to software that supports it. Disk images load and save to/from the MiSTer SD card or a USB drive which is already as fast as it can get using the IEC protocol.

[Juri]

hi Eriks5,
thank you for your magneficent work, is something new? the core is still 5 months old, are there bugs fixed in the upcoming release?
thank you so much again

[eriks5]

hi Eriks5,
thank you for your magneficent work, is something new? the core is still 5 months old, are there bugs fixed in the upcoming release?
thank you so much again

Still working on it. It's done when it's done

[eriks5]

Sneak peek of the latest feature

Sequence 01.gif (3.64 MiB) Viewed 12195 times

can you spot it?

[rcade]

Vertical lines? Authentic, but not endearing.

[ericgus09]

Vertical lines? Authentic, but not endearing.

Its like the Amiga floppy drive TICK TICK TICK .. you miss it when its gone forever..

[jordi]

Mistaken

[LamerDeluxe]

Faint yellow vertical lines used to be a telltale sign that my VIC-20 had crashed.

[rcade]

Binary?

[eriks5]

New development/test release of the C128 core is here!

Changes in this release compared to the last dev release:

• 1570/1571 now support reading from and writing to MFM disks (for CP/M). Passes all disk tests of C128 factory test
• External fast serial now actually works (thanks to a lot of help from https://github.com/thierer)
• Selectable VDC colour palette
• And the most important feature of the core: VIC jail bars, cause it ain't a C128 without! (sorry Bil )

Also merged in the changes Sorgelig and others made to the C64 core.

Doesn't look like much changes, but adding MFM support to the 157x meant having to rewrite most of the existing disk handling code, which took a lot of time and trial-and-error.

In the attachment you'll find the .rbf for the core, and a modified MiSTer main binary because the core needs changes to that for the 157x changes. Disk I/O won't work without the modified main binary. The provided main binary is up-to-date with the latest changes as well. See my previous post on how to update your MiSTer main binary.

[tontonkaloun]

Thank you so much !

[EeDee]

Jail bars for those nostalgic moments. Nice!
Thank you @eriks5

[ericgus09]

<3 Jailbars!

[ericgus09]

In the attachment you'll find the .rbf for the core, and a modified MiSTer main binary because the core needs changes to that for the 157x changes. Disk I/O won't work without the modified main binary.

Im just curious .. I often see cores mention changes to the main mister binary frequently .. usually in reference to disk support, can you maybe elaborate a little what the change is that requires it in this case .. again more curious than anything .. Just trying to learn. Thanks! (you don't need to go into super detail, I am just trying to understand the issue better). I get this core disks functions wont work without them .. just curious what changes have to happen on the mister main binary end.

[Malor]

I hope the bars are optional? They look like crap.

[eriks5]

can you maybe elaborate a little what the change is that requires it in this case .. again more curious than anything .. Just trying to learn. Thanks! (you don't need to go into super detail, I am just trying to understand the issue better). I get this core disks functions wont work without them .. just curious what changes have to happen on the mister main binary end.

In a nutshell, adding support for .d71 and .g71 formats. These have double the amount of tracks since they're dual sided. With .g71 there's the added complexity of needing to support MFM formatted tracks that store about twice as much data as a GCR formatted track. The main binary handles the details of the file format itself, so the core only has to deal with the data for a single track and not how it's stored in the files.

[rhester72]

@eriks5 Does that imply that in C64 mode it supports G64 as well? If so...wow. This may be another core supplanting another like the 7800 entirely functionally replacing the 2600 one.

[eriks5]

@eriks5 Does that imply that in C64 mode it supports G64 as well? If so...wow. This may be another core supplanting another like the 7800 entirely functionally replacing the 2600 one.

The C64 core also supports .g64 images. In fact, that's technically the only format it supports for the 1541. The main mister binary converts .d64 into .g64 on the fly. For the C128 core it does the same for .d71 to .g71

[rhester72]

The C64 core also supports .g64 images. In fact, that's technically the only format it supports for the 1541. The main mister binary converts .d64 into .g64 on the fly. For the C128 core it does the same for .d71 to .g71

I did not realize that! Thanks for the tip.

SUPER excited for the C128 though - it's the ultimate 8-bit from my past. Appreciate your efforts very much!

[kathleen]

Thank you @eriks5,

I really like the VIC jail bars option. It's impressive how now the display mimics the original hardware.

Thanks again for your hardwork

[AmintaMister]

Thanks Eriks5! The VIC jail bars are so important for the reproduction of the real hardware that I would like to reproduce them also in the C64 core, is it possible?

[eriks5]

The VIC jail bars are so important for the reproduction of the real hardware that I would like to reproduce them also in the C64 core, is it possible?

Should be easy to backport it. I purposely try to keep as close to the C64 core as possible to make cherry picking commits from that repository easy. Works the other way around too

The VIC jail bars is a standalone commit: https://github.com/eriks5/C128_MiSTer/c ... 08ad805883
Biggest departure from the C64 core is that the display resolution doubled, the jail bars are rendered at half-pixel widths to make them look better and offset from the actual pixels. For the C128 core, that resolution was already doubled because of the VDC.

There are probably other fixes I made along the way that could be backported. I was planning on going over every little thing I did at some point and see if it's something that could possibly be backported.