This is the place to discuss our glorious C64/128 machines and their very active scenes. Other C= 8-bits welcome, too!
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Seattle, WA, USA

by intric8 posted Sat Nov 10, 2018 4:41 pm

The C128D has taken up most of my concentration once I got the keyboard working last week.

It became immediately obvious I had so much to learn! And that learning has been both a bit of a struggle yet also a ton of fun so far. I really need to sit down with an old school paper back about the 128 and just read it cover to cover. The C128D is so different from what I'm used to. I found a few great books here, which I plan on starting this weekend.

In any case, the first order of business is to get the 80 column mode working. I have two different monitors which can be used: the Amiga 1080 or a Commodore 1084S. In order to use 80 column mode (via RGBi) I needed to pick up an 9-pin cable, which will arrive later today.

That's the easy part - minus actual software I can use in that mode. But I'll get to that part later.

Next up I wanted to use my Ultimate ii cart for loading various files. What I soon learned was the internal drive is set to '8', and there's no hardware switch for flipping it to a new ID - one of the few oversights the C128D designers made. I can see why they did what they did, but they had considered so many other forward thinking design changes it surprises me a little bit that they didn't consider this part out of the box for consumers.

You can still use the Ultimate ii cart, but you have to switch its ID to ‘9’. But that’s a non-starter for me. So many games are hard-coded to seek the 8 drive for mounting and running properly.

Commodore did, however, design the 128D motherboard in such a way so that it could indeed be changed. It requires cutting two traces to do so, but they were put on the board in an obvious fashion for this future mod. The two traces were actually designed to be bridges for the drive number.

So, according to Mattsoft, we can attach 3 test clips, cut 2 traces and then use strong double-sided tape to hold the selector to inside of the case.

In an ideal world, we’d do something like this (see photo below) using the pre-cut hole in the back of the case that was made for the RF modulator selector.

Concept provided by Sven Werner:

In an even MORE perfect world, the switch would be vertical. Frankly, I wouldn’t even need 2 switches (for 8, 9, 10, 11). I’d really only ever need just one switch to go between 8 or 9. It would make the little DIP gadget even smaller.

The problem right now is that the internal RF Modulator switch is in the way. Do I even need an RF Modulator (the device used back in the day that let you switch the machine from channel 3 or 4 in North America when using a regular TV as a monitor)? No - I don’t. But removing the RF modulator would mean removing the entire motherboard from the case and de-soldering. Semi-major surgery.

That’s a bummer. It might be that we end up mounting a little switch box to the back of the machine instead - TBD on that.

rom upgrades
Another very cool feature of the C128D is that it has an empty ROM bay waiting to be used for additional enhancements.

You can install ROM chips to put GEOS inside your C128 (or RAM expansion) and load it instantly. The Commodore C128 has an extra socket that can hold 60K of GEOS code so it does not need to be loaded from disk.

Or, you could install a ROM with BASIC 8. The BASIC 8 ROM is useful as it allows you to write programs that extend the Commodore 128s BASIC graphic commands.

There is also a ROM called the Servant, which is a ROM-based utility package designed exclusively for the Commodore 128. It includes a lot of built-in features like a very robust disk copier, full 1581 partition support, convert disks into auto-boot disks, and more.

But then Matt discovered there’s a gent who creates a C128 Multi-ROM that has 8 different images on a single ROM. Not only that, it is 100% software driven - just holding down various keys during boot will activate the different images! No hardware switches needed. Nice!
Jiffy-DOS switch
Remove toggle switches and turn your JiffyDOS on or off via software menu

7 C128 Option ROMs including
Basic 8 (Hold CTRL on boot to activate)
KeyDOS (Hold ALT on boot to activate)
Servant (Automatically runs)
Super Chip A (Press HELP to activate)
Super Chip B (hold CTRL on boot to activate, 80 col required)
GEOS (rom only, original disks still required)
TASS (Hold CTRL on boot, requires 40 col 64mode)


Unfortunately there aren’t any in stock right now, but potentially in December they’ll get re-stocked.

That’s when I also discovered that for those who have a 1700 128KB RAM Expansion Unit (REU) or 1750KB REU, those devices also have an empty ROM bay for these chips, too. So many options to expand these things!

So then we come to the final piece of the puzzle for today - the software! There really wasn’t that much made for it to begin with. Most of the software that supported C128 native mode was business software: word processors, programming programs, spreadsheets, file management, accounting programs and so on.

On the games side, few developers ever supported any of the 128’s extra benefits. Infocom did, as their text adventures took advantage of the 80 column display potential. And a tiny handful of games tapped into the extra RAM in what’s called “enhanced C64 mode”. Original native C128 games only come to a few dozen commercial titles in all.

But several terminal programs were made for the C128. Coupled with the 128D’s fantastic keyboard it can become a really great BBS-calling machine.

I asked the sysop of ParticleBSS (which is run off a C128 with REU) and his favorite terminal is called Dialogue 128 by Tripple Point Software. I found the program, and that’s where I fell into a weekend of work: how to write programs (like, d64 image files) to actual floppy disks. I needed to learn this process because - at least for now - a lot of software just won’t work properly if booted from the 9 drive, which is what my Ultimate cart would need to be in order to not conflict with the 128D’s internal drive.

Over the course of a day, I learned to update my Ultimate ii’s firmware (o. m. g.!) which was a massive ordeal. Once done, I was able to connect my C64 breadbin and ultimate 2 cart to an external 1541-ii drive. I can write d64 images to disk all day long.

What I discovered after the fact, however, is that the ultimate does not natively support writing 1571 or 1581 images! In order to do that, you need a spare 1571 drive (I don’t) and then you can use the 1541 Ultimate cartridge on a C64 and write images using a tool that will let you write the disks correctly.

I’ve come to learn that the Uii cart cannot write D71 and D81 files by default, but it can read them. This tool tool writes .d81 images as well. A lot of C128 native software comes on D71 images.

Who knew? I sure didn’t. So the files are out there. But getting them to floppy takes a bit of work. It makes me want to get my internal drive off of ID 8 that much more.
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by mattsoft posted Sat Nov 10, 2018 6:05 pm

Nice write-up. The 128D really is quite a gem IMHO.

This post is motivating me to crack the hood on the 128D tomorrow and take another look (and some measurements) about where we could discretely mount an internal drive selector without any surgery.
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by Bulletdust posted Sat Nov 10, 2018 10:44 pm

I remember in the day one of my mates had a C128 while the rest of us had C64 Breadbin's and 64C's. We'd all get together with our software, a bunch of blank disks as well as our Commodore setups and 'trade' games and software. Not once did I ever see my mate boot that C128 in anything but C64 mode!

In the end we actually sort of forgot that it was even a C128!

However, out of all the 8 bit machines, the C128 really was a gem of a machine, definitely one of the best! A bugger to diagnose issues on when they play up however.
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by McTrinsic posted Sun Nov 11, 2018 6:48 am

I loved my 128d when I had one back then.

The only soft for it that comes to my mind are 'Gato', a submarine- sim.
And I think Elite had some special additions when running on a 128 but that is getting a bit blurry.
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by Dynamic_Computing posted Tue Nov 20, 2018 10:39 pm

Do you have a link for the guy that sells those 8 in 1 ROM's?
@10marc1 on Twitter
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Seattle, WA, USA

by intric8 posted Wed Nov 21, 2018 11:51 am

They are out of stock. But we're all waiting patiently for this.
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Zippy Zapp

by Zippy Zapp posted Tue Dec 18, 2018 2:28 pm

I had a 128D briefly back in the day. By 1986 I had bought a flat C128 that I was using as a C64 mostly. When the 128D came out I had to have it. So I did the old return it to Toys R Us trick. Even though the C128 was long past being returnable, back then you didn't need a receipt and they gave you full cash refund. Used it to get the 128D. Had that for a short while and found that I liked the old flat 128 more. So back to the Toys it went. This time I just traded it in for a new 64C and a 1581 drive (still have both).

Fast forward to 2013 I got the itch to use the 128 again. I already had my original 1571 and 1581 drive so just needed to find a computer. I found a NOS 128 and 1571 never taken out of the boxes for a decent price so I bought it.

The 128 is still my favorite 8-bit of all time. The BASIC is great, the keyboard is great, the bells and whistles that it has are awesome.

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