I never did own a C128, I went from my C64 to my Amiga 500 in 1992. But I always wanted to own a C128 back when I used to frequent the BBSes, we had a lot of them in our city and t he first one I ever logged on with my C64 and 1670 modem was called "The Extra One" which was run on a C128 using EBBS software. He could do 80 columns with it which was a nice feature given all the IBM BBSes in town. I eventually created a 4bit wide font for my C64 terminal and a 80 column mode for it that included IBM graphic characters. Not the easiest to read but it worked. Later I used an A500, A1200 and A2000HD. I REALLY miss those days, I enjoyed them far more than I do now to be honest.

Awesome. LOL GO 65! I too have a flat 128 which is probably my favorite 8-bit. Keep up the good work!

Update: the PLAY music volume is more of a bug in the documentation than in the implementation. I go into this in more depth in this follow-up video: kzfaq.info/get/bejne/ntabfbWLv7Kacqs.html Index: 0:00 Intro 1:20 Easter Eggs 2:34 Secrets? 3:50 RUN/STOP to boot to machine language monitor 4:32 Two banks of colour RAM 7:12 Bugs - Caps Lock Q 8:15 LIST A 9:06 2^15 9:29 Negative Relative LOCATE 11:27 INPUT from screen 12:36 PLAY music volume 14:35 RSPRITE() - 16 sprites?

Yay, I've discovered a new channel! Subscribed immediately. :) This is great. I had no idea about these bugs, interesting. Particularly the 16 sprites is fascinating to ponder.. What if we really had been given 16 sprites, wow. Mind blown.

Well youtube recommend me an amazing video! I love finding these type of videos on classic PC's!

The C128 80-column mode is a lot more flexible than people think. The graphics chip is programmable, allowing you, for instance to add more lines and have more characters per line. If you have enough 80-column video RAM (C128D or a user-hacked C128) you can even set up a very dense screen of like 120 characters by 50 lines (interlaced). IIRC, C128 BASIC is even smart enough to know that the screen has been set up to a non-standard configuration, and just go with it.

hi, it's funny that youtube recommended your video and at first I thought it was the 8 bit guy. So it was a happy accident finding your channel. I enjoyed your video and it's nice to see so many people keeping alive retro computing. The C64 was my first computer and I literally would have killed for a C128 :)

Great stuff. I was not aware of some of those BASIC bugs. I love programming on the C128 - what a nice machine

Very interesting video , thank you ! I love the C128 .

I started home computing on an Amiga 500, but in recent years I've been very interested in looking back at the C64. I love your presentation style and entertaining facts a lot and look forward to each video. I secretly hope for a one-off Amiga video but I know they were a lot less common outside Europe, and it's outside the realm of 8-Bit :D

Always love your 128 vids. Keep it up!

Excellent video, and great patch/badge.

Interesting feature, that go c65 one. Haha. If the c128 had a built in sprite multiplexer. Wow. What a concept. That would have made quality of c128 life even better.

How have I only just come across this channel!! I love this stuff. Subscribed! I have just managed to get my hands on a 128D and matching monitor, unfortunately it didn’t come with a keyboard. I was able to test it with a mates keyboard and discovered it won’t read disks, probably a dirty drive but read fine from a cartridge game and all seemed ok. It also has its warranty stickers intact. The struggle continues to find a keyboard.

Nice easter eggs and bugs. Wow, I didnt know about "go 65." I gotta try that on my C128D some day.

I think it’s funny how all the retro computing guys also follow musicians. Me included. My 128 came broken Christmas Day. The store insisted we get service rather than exchange. The service center had to replace the motherboard. I really enjoyed the 128.

The Adam Neely shoutout made me subscribe!

the first 16 bit gaming system, the turbo grafx 16 was not true 16 bit, but a mirrored 8 bit basically, a virtual 16 bit....obviously they were already toying with the idea when designing the C128

13:18 the lick ^_^

I wonder how many people really tried go 65! :-)

Great video. the C128 is my favorite Commodore machine. Here is another curiosity regarding the machine: if you type QUIT or OFF in direct mode you will get an ?UNIMPLEMENTED COMMAND ERROR. I'm not sure what those commands were to be used for but it looks like engineers forgot to take them out of the BASIC ROM before the machine went into production.

The Q capslock got me. It's one of those oversights of how did that happen?

I typed "GO AMIGA" and it prompted me to insert a disk with a funny hand. Is this normal?

Nice one and I love that original Kikstart gamedisk...

I have a C128D, but havent used it for anything except for "GO64". Still love it though

Regarding the volume bug mentioned at 13:27: There is no bug and it is not to be expected to fix something which is not broken. ;) It's intended that PLAY uses only a single digit from 0 to 9 which is internally mapped to 0 to 15 of SID's volume register. It was never supposed to be a U command with value 10 to 15 as opposed to the VOL command. See the ROM listing at $703C where the SID volume scale table resides, which uses the volume part of the PLAY command at $6EDD. I don't know the english user's manual, but despite all the bugs the german version has, the description for the U part seems to be correct to my surprise.

I had no idea there was a sneak peek of the C65 included in the C128, crazy stuff

I still have my 128 buried in the closet. Some of these "secrets" are actually in the user manuals. Didn't know about the ROM fixes. Great nostalgia!

That audio command is quite interesting and actually fairly cool because as far as I know most modern computers (without a pc speaker) don't even have this feature. Heck, I've never even seen a game engine with this feature.

Great video, keep 'em coming! (and thanks for the shoutout :) )

on first glance, I must assume that the extra digits on the exponent calculation must be because it is doing a floating point calculation. That's not a bug ... it's a feature. It seems clear to me that the C64 software defaults to integer math (i.e. whole numbers) and the C128 software defaults to FP math. FP attempts to be more precise by calculating down to the Nth decimal place ... unfortunately, the buffer is only so big. So. if your math turns up anything of a positive nature anywhere in the calculation past the decimal place you're going to get a 1 at the end of the buffer, preceded by as many zeros as it takes to give the best precision it can. Basically, it is saying, I calculated to this many decimal places and stopped, with the 1 being the stopping point.

There was another sort of easter egg, if you set a variable REAL=64, then you could type "GO REAL COMPUTER" to go to C64 mode. The go command appearantly evaluated variables and ignored any extra… (I couldn't verify it right now, as appearantly my VICE installation lacked the ROM files for C128, maybe those are on my old HDD) :D

Haha! Nice Adam Neely reference! Do you play bass?

Great video as always. I actually found the shift lock bug myself but only after repairing a broken keyboard on one of my many 128’s. I used shift lock to test all shift characters and when I got to the q I thought I missed a trace repair so I took it apart again! I finally tested on another c128 after finding no fault in the repaired keyboard and had the same result there. I actually couldn’t believe that such a huge defect existed. My favorite part of your video was the input from screen. Wow! Id like to see a video on machine language for the c128 video mode as that graphics chip was rarely used but it really only did bitmap but still it would be interesting. Id also like to see machine language in z80 mode. What graphics chip does z80 mode use? Ok I have to pull one of my 128’s out soon and check. My Amigas are out right now.

You've got a new subscriber! Most interesting, thank you very much!

There is another secret, which is used for copyprotection, in C128 mode, and game accesses c64mode at the same time and runs code their and returns varables back to C128. Some C64 games wont run on C128 any mode, as the C64 mode real and virtual mode isnt exactly the same. The C128 is a bit of a mismatch. There was internal talk the C128 and Plus4 would be combined to make a Cplus128, it never happened as the team was used to make other stuff. Some revisions of C128 arnt the same, some will do somethings and some wont, some will run a C64 game and some wont etc. The C128 was quite a mismatch computer, the CBM team just used their time with the Amiga and ran out of time on the C series.

8:44 "list dog" gives syntax error, because only the first 2 letters of variable names are considered. And DO is a reserved command in Basic 7, so LIST DO is obviously drives the basic interpreter crazy...

oh your C128 is really a nice machine! I appreciate the flat home computer case. Maybe i will try to get one in the future. I wonder if there are any games you can use in Z80-Mode?

13:50 - I wonder if U015 would work (in case just the first digit is being skipped).

I thought that the banked colors could be used to make nice fades and flashes by copying a lighter/darker version of the colors into the other bank, then using it, and so on and so forth. Looks like i'm wrong!

I started reminiscing good old times with 128 and basic, and if I remember correctly, there was a typo in the example music program list in the user manual, the song was Invention something something. No matter how many times you thought you typed it correctly, the notes on the channels would go out of sync at some point in the song and tears of frustration were imminent. Don't know if that was ever fixed in later user manuals.

9:30 - that's more likely a feature of the LN and EXP routines. a^b = EXP(b * LN(a))

V1 O2 U12 IDEFG QE IC WD >> what happens if you found the HEX address of the volume and changed it to F which is 15? could you do that??

!!! WHOA !!! Go 65?! Holy Crap! I never knew that.

what happens if you try UF? I have a 128 next to me but no energy :D

I wonder if the volume in the PLAY command is supposed to be in hex. Or maybe if you used the six characters that follow the numerals, it would work.

I so need to get my 128 fixed. Of some reason, an A500 PSU came into contact with it, which wasn't an appreciated aquaintance for the poor 128. A very unfortunate cost savings method from Commodore's part, to use the same PSU connector, but not the same voltages.

After watching this vid, I pulled out my (sickly) 128D. Turns out the board is (c) 1985 and exhibits exactly the same 'symptoms' as your C128 board including the small q. My big interest was the dual color screen you demonstrated because the 'sickly' part of my 128 is that it has messed up color - black bars on the foreground kinda like when you first changed to the second screen. (Ive replaced the color RAM so it's not that). If i poke a color across the whole screen only a very few characters actually change color. After your vid I checked this now on both screens. Any ideas where i should be looking for the fix? Great vid by the way - thank you!

You should try to explain bugs with STEP 0.5 in FOR loops.

interesting volume 1 is still muted...

The color RAM thing... Fill the screen with block characters and use color RAM to define a picture... You can have two "video pages" maybe?

I have a 128D sitting aside, but I need to go through the board and possibly keyboard looking for damage... the physical end of things appears find (cable, connector, etc) but I'm missing half my scan, every other key is dead horizontal so I've got a dead line or a hung gate...

got myself one of this babies. the jailbars are actually really bad in the video signal. any suggestions besides the "clear video" solution? mine looks like yours in the video - way worse than a c64

Would it be useful to replace the early ROM with a later one in my flat C128?

Would it be possible to replace the Kernal Rom chip in the c128 with a newer one and it would fix these bugs? I found an eBay seller that has quite a few Kernal chips that he's saying are "for the C128". The date on the chips are 1986

List a-b list 20-

Great video! I recently got my C128 working and I was excited to see if I could access 65 mode. Although my rig has all of the other characteristics you showed, mine produces an error if I try to GO 65. It looked like it booted into a functional C65 machine in your video. Will you make a video showing us around in the C65 mode? Thanks.

Great video, I just Subscribed, I had a commodore 128 when i was 14. I seem to Remember a third mode, 128 Mode, 64 mode and a C80 mode. Any info on the C80 mode?

Can u boot into 128 mode with a c64 cartridge inserted?

the go 65 get a syntax error in vice emulator

How about LIST A%?

Are there any C128 exclusive games?

actually the bank switching would be good for banks, as you scroll the bank you are not viewing, then switch banks, you don;t need to copy from one to the other. The advantage of this is that the code does not need to run when the raster scan is offscreen as you do on the c64.

uhm, afair the early 128-D plastic had same board AND chips inside, or? you can also switch to 2mhz mode in c64 mode but screen blanks, good for calculate things, and switching then back POKE 53296,1 and back to 1mhz by ,0

1:38 Bil Herd also has a KZfaq presence: kzfaq.infovideos 6:45 Can you do an "REU scroll" on the color RAM? 8:11 The C128 has a vector at ($033A) for decoding the keyscan code, so you can supply your own tables that don't have the Caps-Q bug. 9:06 Exponentiation is implemented using polynomial approximations, which means that round-off errors are always expected. If you were to multiply this out in a loop, you would get the right answer. 9:37 The Jiffy clock on the PAL C64 counts in 1/60ths of a second since it uses a CIA clock as its Jiffy timer. Is this true of PAL the C128, or does it use a 50-Hz scanline interrupt for its Jiffy clock? (I suppose the interrupt itself would be 100-Hz for a split-screen.) Even for the NTSC C128, its screen-refresh rate isn't exactly 60 Hz. 10:07 Are the ",8,8" arguments pixel coordinates or the graphic-area size? Because if they're screen coordinates, wouldn't you want ",7,7" (with the coordinate values being inclusive)? What is the LEN() of the string that was returned? The empty pixels around the "A" would return CHR$(0) which wouldn't be displayed with a PRINT statement. 12:26 You should still be able to use GET A$ with the screen. I used this method to implement a primitive Print-Screen capability on Commodore-8032s back in high school. 14:46 It seems odd that they use "1" as the base of the sprite numbering when the hardware documentation generally starts at "0". Did they think that zero-based indexing was too complicated for the people who were going to write graphics-intensive programs in BASIC? 15:24 It would create a real mess in the VIC-II register layout to add eight more sprites - unless they were added as a second "bank" of sprites where one bit in the chip selects which of the two banks show up in the usual register locations. The VIC would also have to steal more cycles from the 6510 at 1 MHz. 16:15 Always secretly include your next product in your current product! (Then, just play video games at work for the next two years.)

11:27 do you then have to do a close 3?

Just courious, would you be interested in my index cards of D128 secrets that I had accumalated over time? I have quite a few...lol

kikstart. Man that was the game i played the most, except maybe Ultima iv

Tryed most of thease with vice none of them worked using the 1986 version

hello in c128d is the play volume bug fixed?

Why would people care about a buggy version of BASIC if they got this computer? Anyone willing to collect these things these days would probably just write an EPROM with the updated version of they cared that much about it. As I'm assuming they'd be the type of person with the tools and know how.

So the last Easter egg can not work the way you put it. A C128 from 1986 can not use a computer C65 mode, because the computer was first developed in the 90s. But the turn-on display, that can certainly be achieved with the C128. So far, genailer trick

Thought this was an 8bit guy video but it some knock off.

That is a great video, but could you please stop this “talking hand“-thing? I don't know about the others but this is distracting me af.

GoWin10

Repetetive.