I have 3 from the list... unchecked ;-)  So I guess some were not counted. In "other" I have C116 and  Max Machine.

Steve

My CBMXfer can list all standard cbm basic prg files and will auto-detect the appropriate tokens based on load address of the file.

http://www.6502.org/users/sjgray/software/cbmxfer/cbmxfer.html

Steve

Yes, this is documented on my CBM-II page. I made this fix long ago to my LP machine but only got around to documenting it recently. It seems strange commodore would mess up the graphics characters like that...

Steve

I must say I'm slightly jealous... you have the ultimate B-series machine, which is something I've been trying to make for a while now. Congrats! Very nice job. I'm going to have to try to assemble my own BX720D ;-)

I look forward to the new IEC features you are working on. Oh, and thanks for the fast RAM check!!!

Steve

Ok, so I burned an EPROM and did a quick test. Yes, I noticed the error on first IEC access.
It works with my MSD-SD2 as device 8 on IEEE, and the uIEC as device 10 on IEC! Nice.

It's actually funny... since my "cassette to IEC adapter cable" is plugged into the B machine and the uIEC uses the cassette connector as power I ended up using a 64C simply to power the uIEC.... I may have to add a +5V tap on the the adapter ;-)

Which, brings up a question.. what exactly do we call this "cassette to IEC adapter cable"? It needs a nifty name... Should we settle on C2N2IEC ? Or, perhaps C2IEC, CX1541 or XC1541?


image uploader

Steve

Courage I have... time... not so much ;-)   I have plenty of EPROMS and an eraser, so i'm willing to test when I can. Glad to hear you are making improvements!

Steve

All known B roms start with "9012" so that number is certainly interesting. The 700 motherboard I received from Anders has a kernal rom labelled "901244-03B", and character rom "SVT 700". The last known kernal seems to be "901244-04a".

The LO and HI profile machines use the same kernal.  The Kernal code at $E260 initializes the CRTC chip using the proper values by reading the register at $DF02 (TPI#2). Bit 6 and 7 of this register are checked. The Bit 7 line is permanently set HIGH on HP machines and LOW on LP machines from the factory. For LP machines, bit 6 determines NTSC or PAL. This can be changed with the LK1 jumper.

There are three tables starting at $EC6F.

$EC6F - HP machines (14 pixel high characters)
$EC81 - LP NTSC machines (8 pixel)
$EC93 - LP PAL machines (8 pixel)

Perhaps your Kernal is a very early one that does not have this check.

Perhaps you can send yours to zimmers or myself for archival?

Steve

I guess I'll add another...No reponse to my email too.

Steve

Quote from: Michau on October 01, 2010, 07:30 AM
Well, I must support the B256, since I have myself upgraded my 610 to 256kB RAM and BASIC 256 But I guess that the P500 could easily be omitted.

I find the 256K ram nice, but I prefer the 128K BASIC ROM. You are of course free to use the 128K BASIC ROM with 256K RAM...  this gives two full banks free to do whatever you want without worrying about BASIC overwritting your data, and the commercial software runs fine. BASIC won't use the extra banks but, realistically, how much space do you need for variables? Your BASIC program will still be limited to 64K.

I wrote an "un-assembler" that took any code and created an assembler file by loading the code into bank3. I wrote a music player for C64 Master composer files by reading the song into the unused bank and having the playback code in bankf. I wrote a file copier that simply read files into bank3 and wrote them back after swapping disks.

Steve

If anyone is interested, I just posted the schematics to a CBM-II RAM/EPROM cartridge that was loaned to me. It might make development easier, but you'd have to build one first of course...

http://www.6502.org/users/sjgray/computer/cbm2/cbm2-24k-schematic.jpg

You could subsitute a NVRAM chip like the DALAS DS1225 to make an updateable cartridge!

Steve

Here is Jim's C=Key page: http://www.jbrain.com/projects/ckey/
Here are pictures and schematics: http://www.jbrain.com/vicug/gallery/c=key

Steve

Quote from: carlsson on September 30, 2010, 09:34 PM
I agree, it looks like the most number of CBM-II items are found in Germany. Personally I'm out of items.

Another option would be trying to use something like Jim Brain's keyboard adapter C=Key but it requires to be reprogrammed to match the CBM-II keyboard layout. If someone can open up a keyboard and follow the wiring, it might be possible to at least recreate the matrix for manual simulation of the signals.

The keyboard matrix has been documented and is on zimmers. According to Jim's page, it's fairly easy to add support for additional keyboards to the C=Key.

Steve

Well, the majority of machines made are B128/610 and all the commercial software (not much) is written for those machines. I'd say you could ignore the 256 models. Similarly, very few P machines were made and they also run at 1MHz so you'd probably have to adjust all the timing as well. If you can easily support all modes that would be fantastic, but it's probably not worth the extra effort.

Concentrate on 128K B-series, autostart, and an easy way to select/change interfaces.

Some ideas for discussion:

A) Default to IEC (since the cartridge is installed that's probably why it's there)
B) Use SYS to select interface (simple, but would not allow mixed access)
C) Use one byte in zero page as "device flag" for device 8 to 15 - if bit is 0 then IEC, if 1 then IEEE (I suggest using 00001111 as the default flag)
D) Use WEDGE command, ie: ">IEC n" or ">IEEE n" sets device flag
E) How to handle two devices with same ID on different interfaces? Perhaps re-map IDs. Device 8 to 11 would be on the IEC bus as normal, and devices 12-15 would be on the IEEE bus. Device 12 would remap to IEEE device 8, 13 to 9, 14 to 10, and 15 to 11. This way no messing with switches or device jumpers would be required. Perhaps this behaviour could be toggled with a wedge command, ie ">REMAP ON/OFF"

Steve

It seems to work fine for me too!

Can you make it autostart and display a simple message on how to activate/deactivate it? Oh, and perhaps a version# as well?

Keep up the good work!

Steve

PS: I also burned the VT-52 emulator to install in the left socket. Interestingly, it seems to autostart but I can't figure out how. It hooks into the system so that pressing ESC-? starts the emulator. Perhaps you can look into how that works and implement something similar...

Germany.... ebay.de sometimes has CBM-II stuff, but I haven't seen too many loose 720 keyboards. Main problem with ebay.de is a lot of sellers won't ship to north america and some only sell to europe... perhaps not a problem for you, depending on your location.

Steve

Good start. I will try this on the weekend.

Steve

Quote from: RobertB on September 16, 2010, 02:29 AM

Quote from: Steve Gray on September 16, 2010, 12:22 AM
RGB Analog was used in early arcade units...

And on Amiga computers, too.

True, of course ;-)  These video conversion boards seem to be popular on sites geared toward those arcade units. In the Amiga community the focus seems to be on "scan doublers" and "flicker fixers"....

Steve

My first reply pointed to a page that explains the 8 and 16 colour issue, and tells you how to build the required adapter to get 16 colours from the poster's board in question. It's a very detailed page. Other pages on the site even cover the board itself. A good place to start.

Secondly, the web page for the board in question is incorrect. It describes the board as a "CGA to Video" converter. In fact, it is actually an "RGB Analog to Video" converter. CGA is IBM's term for RGBI, which is what the C128 uses. RGBI is a DIGITAL interface. RGB Analog was used in early arcade units and is much more like VGA (the main difference being the scan rate).

Steve

Yes, this has been discussed in other threads here.... anyway, check here:
http://sites.google.com/site/h2obsession/CBM/C128/rgbi-s-video

Steve

Quote from: bacon on September 09, 2010, 08:30 PM

Quote from: Steve Gray on August 31, 2010, 05:55 AM
I am wondering if it would be possible to modify these sheets to "re-wire" the keyboard matrix to be compatible with commodore machines? You can buy silver contact pens that let you draw conductive traces. Perhaps that might be easier than hacking up your Commodore 128 keyboard?

I tried this a few years ago. It doesn't work; the "ink" won't stick to the sheets.

What about trying the silver tape used for duct work. Cut it into thin strips. Should be flat and conductive and fairly cheap...

Steve

  I've been doing some thinking about this recently. I guess the questions are... how much work do you want to do? Do you want it to look like an "authentic" C128 keyboard, or are you just looking for something that works?

  One option would be to use a standard PC keyboard and a converter circuit, like the "C=key" from Jim Brain. Perhaps there is a way without needing any electronics?...

  I thought about what would be the best layout for the C128 (and C64) and it occurs to me that the standard PC keyboard layout is pretty efficient. I have been opening up some of my keyboards to look at them (both Commodore and PC ones). Today's keyboards are much different than the typical commodore keyboard. In fact commodore keyboards have quite the variety themselves.

  Most modern keyboards use a membrane consisting of two sheets with traces (much like a circuit board) and pads separated by a third sheet with holes. When you press on a key the rubber part presses down on the top sheet, through the hole in the middle sheet and makes contact with the bottom sheet completing the circuit. I am wondering if it would be possible to modify these sheets to "re-wire" the keyboard matrix to be compatible with commodore machines? You can buy silver contact pens that let you draw conductive traces. Perhaps that might be easier than hacking up your Commodore 128 keyboard?

  I have a bunch of SX-64s with missing keyboards. If I could find some cheap PC keyboards that could be modified easily/cheaply they would be much more useful ;-)

It would also be possible to wire up the numeric keypad or make 8 separate function keys etc.

SX-64 and C128D keyboards are in demand.

Thoughts?

Steve

So, lets see...

* top row... moving function keys and special keys.... some are "lock" keys that protrude through the circuit board...

* move the entire keypad down to add an extra row, reducing the wrist-rest area.. lots of plastic work needed.

* major shifting of SHIFT,CONTROL, ESC, RUNSTOP, CAPS LOCK, C= keys etc... lots of rewiring of the circuit board plus moving keys where none exist (and likely where circuit traces are)... major work

* separate cursor keys... possible with additional chip (like the C65 does)

Overall.. extremely hard, but then not impossible. The main problem is that the keyboard matrix is optimized for the normal placement of each key, so moving them is not trivial, plus each key is not soldered on separately but integrated with the plastic.

Steve

Quote from: Michau on July 22, 2010, 04:36 AM
I have created an updated Kernal and was able to burn it. My 610 boots OK and uses the IEEE drive well. However, IEC will indeed not work - I checked that my IEC status variable has wrong values (PEEK(1020)). This needs debugging.

The process of reassembling and burning a new EPROM each time is rather cumbersome. I think for debugging purposes, it will be better to create a simple file that is to be loaded at $0400 with the routines. This way it will be possible to modify it without wasting EPROMs.

I ordered a nullmodem cable so I'm hoping to connect my PC via RS-232C to be able to upload files easily.

Yes, we discussed development options earlier in the thread. You might consider Jim Brain's ROM-el. I suppose using $0F0400 ram could work but then you'd need to transfer the PRG and LOAD it... One other option might be CBMLINK. I believe it can load to memory from PC and execute it. You will need to load in the CBMLINK client but at least you won't have to continually transfer the new code to disk. I've never tried it, so if you get it working let us know.

Steve

Edit: CBMLINK also uses $0400 memory so maybe that's not going to work... I think Anders mentioned putting CBMLINK on a cartridge so if you get a cartridge from him that might be an option. I'm still convinced the cartridge way would be best for people who don't have the ability to burn roms and build adapters. A cartridge could hold upto 24K of ROM so we could put all kinds of things on there... JiffyDOS, wedge, cbmlink, extended monitor, sidplayer (wishfull thinking)...

Quote from: Michau on July 15, 2010, 03:13 AM
WooHoo, it works! I bought a bunch of DSDD Maxwell diskettes, supposedly some C64 games were on them. I reformatted them and they work! 1MB on a disk which would have only 360kB on a PC - that's really good.

See attachment

I compliment you on your choice of computer! Contrary to other opinions expressed here, the CBM-II machines were actually quite advanced and hardly obsolete at the time. Their pricing was inline with the PET/CBM machines they were designed to replace. Lets not forget that they ran at 2MHz, supported upto 1MB ram, had a SID chip, and probably the best keyboard Commodore ever produced on an 8-bit machine. They even allowed an 8088 coprocessor board to run MS-DOS.

The 8250LP is a beautiful drive, with amazing capacity at the time. The combination of B128+8250LP makes a sharp looking system (the LCD monitor doesn't hurt either).

As for DSDD disks in an 8250... don't try reusing disks that have been previously formatted on a 1541/4040 or PC because they probably won't work due to the 48/96-tpi tracks meshing with the odd 100-tpi format of the 8250. Brand new, unformatted disks is the way to go, or alternatively use a disk bulk eraser (if you can still find one) to wipe out the formatting completely from a previously used disk.

If you need/want more info on the CBM-II machines check out my web page:
http://www.6502.org/users/sjgray/computer/cbm2/index.html

Steve

Quote from: airship on July 12, 2010, 06:32 AM

Quote from: Steve Gray on March 20, 2010, 11:10 PM
- Adapter to connect 4040/8050 or SFD-1001 to C64/128

Fixed that for you.

Thanks, but it still could use some fixing...

- Adapter to connect 2031/2040/4040/8050/SFD-1001/8250/8250LP/9060/9090 to VIC-20/C64/SX-64/Educator64/C128/C128D/C128DCR/C16/C116/+4/C65

(I couldn't remember the model numbers of the 8 inch IEEE drives ;-) )

Steve