Recent content by Lawrence Woodman

There was a program to use +64Kb memory as a ramdisk under CP/M-85, it was called RAMDRIVE/85. It's mentioned in issue #20 of Sextant: https://archive.org/details/sextantissue20janfeb1986/page/n5/mode/2up?q=ramdrive

The problem with VT-100 is that the control codes could be too long for the space allocated by some programs. I would go with ADM-3A, this was also emulated on the Kaypro and C-128. VT-52 or possibly Osbourne 1 emulation would also be a good choice.

You should see: ALPHA

In addition to what others have said, the filenames use the lower 7-bits for the filename proper and then the remaining upper bit, bit 8, can be used for other things. For example bit-8 can be used in the 3 letter extension to indicate if the file is read only, invisible, archived. Other CP/M...

This is interesting. I wonder how far that was intended to be stretched: CP/M > CP/M-86 > Concurrent CP/M-86 > Concurrent DOS > DOS Plus > DR DOS > ?

If that is your only reason then you are in luck. There's lots of areas that you can use in zero page without worrying BASIC. I'm not as familiar with the PET, but I'm pretty sure you could use unused areas such as: $00A2 and $00FF. You could also use areas that are only used temporarily by...

It would require hard coding the page address of each address: LDA #65 STA $0400, X STA $0500, X ...

There is one other option, you could set up a series of LDA/STA instructions for each page and just run through them or use them as subroutines as appropriate.

In the CP/M world the undocumented 8085 instructions weren't really known about for the majority of people until quite late in the day. I can only think of two examples of their being used: i. An enhancement for BDS C to speed up things using undocumented 8085 instructions ii. I'm pretty sure...

This brings back fond memories as I had one of these as my first PC in about 1992. Mine booted into DOS from its HDD but the floppy drive didn't work so I wrote a small program using debug to transfer files over an RS-232 link from my dad's machine. The first program I transferred was a proper...

As mloewen says they are available in the *Humongous* CP/M Software Archive, specifically on the Walnut Creek CD - although there are lots of different versions of these tools available on it. If you look again at the article you will see a link near the start of each tool section which links...

QL is probably my favourite utility. It's a text viewer that displays a directory of files and then you can easily look at each, even if they are squeezed or crunched and held in a .LBR file. It also contains a hex viewer. For a 10k utility it really is very good. Like Chuck, I'm also a big...

Hello, Does anyone know why the colour map moves between $9400 and $9600 on the Vic? Is there a reason it couldn't stay at a single location such as $9400? I've wondered about this for a while and there is probably an obvious reason that I'm missing but I would love to know. My interest in...

Hello, I've been looking at the .CBM images on the Walnut Creek CD and while I've been able to find a program to view them, I'm not 100% sure about the image formats. I think the ones beginning gg may have been created by Koala Painter and the ones beginning with jj were created by Doodle...

If you're really not sure, then it might me worth trying out a few possible machine via emulation. This would give you a feel for what it can do and then you can better decide how much more you want to get involved and whether you want to spend money on it. It also helps with with your space...