On Friday 02 June 2006 09:01 pm, Richard A. Cini wrote: Ok, but then what do you use for the BIOS for the target machine? Surely not the same one that's in that package? This is where I get confused. I'm thinking that part won't be much of a problem for me because of all the hardware I have kicking around here. Within fairly easy reach are my old Osborne Executive (SSDD only, darnit!) and a Kaypro 4 which has a 50-wire ribbon coming out of the box and there's another box with a couple of ST251s in it that plugs into that. All I lack is someplace to set it up. :-) -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, a critter that can be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin

On Friday 02 June 2006 09:14 pm, Bill Sudbrink wrote: I might... The problem is, I don't _have_ an appropriate CBIOS for the BBII. Maybe I oughta take another look, see what's out there on the 'net, as it's been a while. I paid way too much for that machine when I bought it (as a kit) and figured I'd defer the costs of the software until later on. Unfortunately the software only came on 8" floppies, and it was quite some time after that I actually acquired any, and I knew of very few people that had 'em. But anyhow when the time finally arrived that I realized that I really should have those sources it was too late, the company had gone out of business. I did talk at some point around there to Jim Ferguson, who designed that board, and he referred me to the guy who did the software (whose name escapes me at the moment), and although I attempted to get in touch with him I never did hear back from him. There's some really nifty stuff in the rom, like the board looking at both serial ports and the built-in stuff to determine where you are talking to it from, adjusting the baud rate automatically in the case of a serial port or the strobe polarity in the case of an ascii keyboard, and when I had the thing in a box with drives hooked up I could tell it to read a sector and it'd do so, doesn't matter what sector size or what density, I could even stick a DOS floppy in there and keep hitting the 'r' key until you'd start seeing directory entries in the DUMP-type display... I have that board sitting in a box here, and really oughta get it out and play with it some, and I probably will, once I unclutter this room some. -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, a critter that can be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin

Okay, here goes. This is how I'd do the whole process on my PC. First of all, I'd pick a disk format. Since you're limited to FM, you might as well use something with 128 bytes/sector and avoid having to write blocking/deblocking code. Another thing to think about is the interleave (physical or logical). I'd go with physical, since you can vary this without changing any code. If you're using a 4 MHz Z80 with that Versafloppy, 3:1 is a reasonable value to start with. 1:1 on slower CP/M systems generally only works when you can read and write a track at a time. However, there were darned few (if any) FM 5.25" formats that used physical interleaving (heaven only knows why). And very few 5.25" FM formats are double-sided (which I think that you'd really want, given the limited space on a FM 5.25" diskette. So you can either write your own 22DISK definition (easy enough) or use an existing one, say, the DSSD Cromemco CDOS one (22DISK CRO2) which will give you about 172K. First, I'm assuming that there's a PROM on the Versafloppy that will load the first sector of your floppy drive into RAM at some fixed location and jump to it. This first sector will contain your boot loader... Next, you need to write a boot loader, which basically sucks in the your CBIOS (see the next paragraph) and jumps to the cold boot entry to load the CP/M's DOS, which will, in turn, load CCP and give you a command prompt. Now, for the tough part. You need to write a CBIOS, which at a minimum, has your terminal I/O routines and disk I/O routines. The terminal I/O is going to depend on what hardware you have. The simplest is using a connection to a serial terminal. More complex routines may be needed if what you have is a video-mapped display. The disk routines aren't too bad. One set of them simply passes the disk parameter block information to CP/M; the other entry points merely store the track and sector and unit and transfer address of what's to be read or written and then reads or writes it. Part of the CBIOS is also the cold boot loader, which loads the DOS part of CP/M. There are other useful features in the CBIOS, such as punch, printer, and reader I/O as well as IOBYTE redirection, but you can do those later. After you've done this, you need to put things together. You can use ASM or ZASM to generate a hex file and LOAD to produce an image of what you want, then concatenate (using COPY) the boot sector, CBIOS and CP/M files into an image file of what's to be written to disk. You can then use the format funciton of 22DISK to create a new system disk, then drop PIP, ED, ASM, LOAD, DDT and whatever else you need onto it. Peruse the "CP/M System Alteration Guide" for examples of how to build a CBIOS and a boot loader. Hope this helps. Cheers, Chuck

Chuck: Going back to an original comment about using the LABEL command in the 22DISK definition, when producing the data for the LBL file, is that data in straight track/sector order? To me this sounds like the easiest way to do "virgin birth" diskette creation since any PeeCee based cross-assembler can be used to build the on-disk cold-start loader and other required files. To answer another question floating around there, this Versafloppy is the first version which uses the 1771 and is single-sided only. It has no ROM, so I have (from the manual) a simple bootstrap loader which will read Track 0, Sector 1 into memory (the cold-start loader) and jump to that. Rich Rich Cini Collector of classic computers Lead engineer, Altair32 Emulator Web site: http://highgate.comm.sfu.ca/~rcini/classiccmp/ Web site: http://www.altair32.com/ /***************************************************/ -----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Chuck Guzis Sent: Saturday, June 03, 2006 2:09 AM To: cctalk at classiccmp.org Subject: RE: Creating new CP/M disk from scratch Okay, here goes. This is how I'd do the whole process on my PC. First of all, I'd pick a disk format. Since you're limited to FM, you might as well use something with 128 bytes/sector and avoid having to write blocking/deblocking code. Another thing to think about is the interleave (physical or logical). I'd go with physical, since you can vary this without changing any code. If you're using a 4 MHz Z80 with that Versafloppy, 3:1 is a reasonable value to start with. 1:1 on slower CP/M systems generally only works when you can read and write a track at a time. However, there were darned few (if any) FM 5.25" formats that used physical interleaving (heaven only knows why). And very few 5.25" FM formats are double-sided (which I think that you'd really want, given the limited space on a FM 5.25" diskette. So you can either write your own 22DISK definition (easy enough) or use an existing one, say, the DSSD Cromemco CDOS one (22DISK CRO2) which will give you about 172K. First, I'm assuming that there's a PROM on the Versafloppy that will load the first sector of your floppy drive into RAM at some fixed location and jump to it. This first sector will contain your boot loader... Next, you need to write a boot loader, which basically sucks in the your CBIOS (see the next paragraph) and jumps to the cold boot entry to load the CP/M's DOS, which will, in turn, load CCP and give you a command prompt. Now, for the tough part. You need to write a CBIOS, which at a minimum, has your terminal I/O routines and disk I/O routines. The terminal I/O is going to depend on what hardware you have. The simplest is using a connection to a serial terminal. More complex routines may be needed if what you have is a video-mapped display. The disk routines aren't too bad. One set of them simply passes the disk parameter block information to CP/M; the other entry points merely store the track and sector and unit and transfer address of what's to be read or written and then reads or writes it. Part of the CBIOS is also the cold boot loader, which loads the DOS part of CP/M. There are other useful features in the CBIOS, such as punch, printer, and reader I/O as well as IOBYTE redirection, but you can do those later. After you've done this, you need to put things together. You can use ASM or ZASM to generate a hex file and LOAD to produce an image of what you want, then concatenate (using COPY) the boot sector, CBIOS and CP/M files into an image file of what's to be written to disk. You can then use the format funciton of 22DISK to create a new system disk, then drop PIP, ED, ASM, LOAD, DDT and whatever else you need onto it. Peruse the "CP/M System Alteration Guide" for examples of how to build a CBIOS and a boot loader. Hope this helps. Cheers, Chuck

Hi I've been working on my M20 to get it to work with a ST251 hard drive instead of the original Olivetti drive. The project has been quite successful. I now have the system up and running with the hard drive. I was inspired to do this by another fellow in Germany that had a failure of his drive and was trying to replace his hard drive. Working with him on his machine we discovered that his controller also had a bad part. Of course, it is a hard to find part. Does anyone have a WD1100V-05 that the would be willing to part with. This is the parallel to serial converter used on the WD1000 or similar controllers. Can you folks check to see if you have one of these on a scrap board? Thanks Dwight