Denial

Richard has this magazine series in his Listings Archive

http://www.vic20listings.freeolamail.co ... mpmit.html

But there are a couple of programs not there (GRAPHOLOGIE and SUPER-RALLYE?). Perhaps you could send them to him to include?

Why are pins B and C jumpered? Is it so that an interrupt is raised when data is received along PB0? I haven't looked at mimmosic's code yet, but I'm guessing that CB2 will be set to HANDSHAKE OUTPUT MODE for this to work? Correct, the receive line must be connected to both CB1 and PB0 so that a in...

coming from Atari 800 and C64 I am used to switch off OS completly and having the ZP "free". on the VIC20 I can not do this but using the IRQs mainly so just to be sure. what are the ZPs which are really free? :) There are very few locations that are completely unused $2A $52 $FB - $FE Th...

Standard (i.e. without a fastloader) .tap files can be converted to d64 using my command line tool

https://cbmshell.readthedocs.io/en/latest/index.html

As Mike points out, if the code tries to chain load another program, read data files etc that needs to be fixed up manually.

A couple years ago I posted several ALA Software games and a member was able to generate the entire list in a D64 file. That would be awesome if somebody again could lump them all in one D64 file. I think this is the thread you mean https://www.sleepingelephant.com/ipw-web/bulletin/bb/viewtopic.php...

Have you got a short BASIC loader program that then chains a longer BASIC program? This combination causes the end of the second program to be overwritten by variables, in this case the start of variables (VARTAB) is not updated.

The IRQ clock, i mean could be placed under the normal screen. And of course with an alarm set and alarm tone. Taking over the IRQ once you've left the FE3 menus would be tricky. If you enter BASIC it would work ok until you wanted to run a program. It certainly wouldn't behave well if you launch a...

SparkyNZ wrote: ↑Sat Feb 03, 2024 8:12 am Right, so this is the result of the CRNCH routine?

Code: Select all

89 20 31 30 00

Correct.

Probably pay me to step through that routine and dump that piece of memory as it goes

Using the monitor in VICE is a good way of understanding how this all works.

Is the BASIC Input Buffer already tokenised? It is tokenized by the BASIC main routine that processes program input MAIN JMP (IMAIN) ; do BASIC warm start ;***********************************************************************************; ; ; BASIC warm start, the warm start vector is initialised...

I miss two thinks on the FE3. - a clock like Mikes IRQ clock - some old fashion screen saver Do you mean these to be available while in the FE3 menus (rather than the BASIC wedge)? For the clock I'll have a think if that would fit on a subset of menus but screen space is tight so that wouldn't real...

I'm new to assembly language, and I would like to learn it for the VIC-20. There's a range of books that could be of help, which one(s) that will work for you depends on your background, how much knowledge you already have of the hardware, etc. https://commodore.bombjack.org/generic/generic-books-p...

This initial test is to check if any key in the matrix is down. Remember this function is called from the interrupt handler, it's trying to avoid burning CPU cycles when there's no keyboard input. Setting the column to all zeros mean the read of the row will be the union of all keys that are down. Y...

Here's the matrix keymatrix.png So 'M' is column 4 (b4), row 'E' (b4). The KERNEL routine loops over each column setting each bit in turn to be 0 and then reading the row. Pressing a key causes the row/column combination to shorted. The 6522 pulls inputs high when unconnected so this results in the ...

One can only think that indirect JMP in the SE code is a brainf*rt ... it really should have been JMP $A2C2 instead: Thanks for the confirmation. The way I work on these disassemblies is I note oddities when I notice them and then come back when I understand the code better. On a related note, I ha...

Oh no. This very bad. Flappy killed my floppy :( In Vice I had my working disk attached. Then I loaded Flappy and played it. Now I turn on Vice and the contents of my working disk is the one of Flappy bird. I was working on my text adventure. Lucky my I printed a listing (file vice.out) and lucky m...