Hi Peter, Thanks for the fast response.
That worked, when used with the SIMH command "SET HDSK1 FORMAT=SSSD8S". Note that I needed to use altairZ80.exe downloaded from your site for this to work (ie "V3.9-0 build 1625"). The Windows executable of V3.9-0 downloaded from the main SIMH site generated errors mounting the IMD file. FYI - I'm using altairZ80 to rebuild a Ferguson Big Board ROM from source. AltairZ80 is a great platform for this work. Thanks for making it available. Malcolm. -----Original Message----- From: Simh [mailto:simh-boun...@trailing-edge.com] On Behalf Of Peter Schorn Sent: Tuesday, 23 September 2014 3:03 AM To: simh@trailing-edge.com Subject: Re: [Simh] altairZ80 floppy disk binary files Hi 1. The file format for the AltairZ80 DSK device is basically a sequence of 77 tracks with 32 sectors of 137 bytes (CP/M 2 can also handle disks with 254 tracks). This is modeled after the FD-400 hard-sectored floppy drive. 2. If you want to mount an IMD disk under CP/M 2 use the cpm2.zip from here http://schorn.ch/cpm/zip/cpm2.zip and use the command attach hdsk1 <yourfile.imd> to mount the IMD file "yourfile" as disk J: Note that the BIOS of the supplied CP/M 2.2 only supports 128 bytes sectors. I updated cpm2.zip to include cpm2_imd which demonstrates this - just use altairz80 cpm2_imd and a blank SSSD 8” IMD will be mounted on drive J: Peter ----- peter.sch...@acm.org On 22.09.14 14:32, Malcolm Macleod wrote: > A couple of questions about virtual-floppy-drive files under altairZ80.exe: > > > > 1. SIMH’s file-format for representing floppy drives > > > > Can anyone point me to some information about the file-format for > Floppy Disk Drives in altairz80.exe under SIMH ?? Section A.2 of > Appendix 1 of “simh_doc.pdf” says that: “Floppy disks are represented > as unstructured binary files of 8b data items. They are nearly > identical to the floppy disk images for Doug Jones' PDP-8 simulator > but lack the initial 256 byte header. A utility for converting between > the two formats is easily written”. However, I’ve not been able to > find a description of how these files are structured. For example, > I’ve noticed that when I create a blank disk in altairz80.exe (eg by > using the command “ATTACH > DSK1 NEW.DSK”, then formatting it using FORMAT.COM on the supplied > CPM2 > disk) that the floppy disk file seems to have an extra 9 bytes between > the actual sector data, so it doesn’t seem to be just raw sector data. > > > > 2. How do I mount ImageDisk (IMD) disk images under altairz80? > > > > The “AltairZ80 Simulator Usage” PDF (altairz80_doc.pdf) makes > reference to IMD files being supported, but I’ve not been able to find > any information about how to do this. For example – if I want to > mount an existing CP/M 2.2 SSSD 8” IMD image, with 26 x 128 byte sectors, as > B: > (under altairz80.exe), how do I do this? > > > > Thanks, > > Malcolm. > > > > _______________________________________________ > Simh mailing list > Simh@trailing-edge.com > http://mailman.trailing-edge.com/mailman/listinfo/simh > _______________________________________________ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh _______________________________________________ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh