Cromix is really intended for operation with a hard disk. I made it work with floppies, but it was always going to be a huge compromise. In particular, it is common for software installations to add links and these links fail if they span physical volumes. And then there’s the general inconvenience of swapping floppy disks.
There were a few hard disk solutions offered in the 1980s, but these are largely unavailable now. The closest that I thought I could get was a WDI II card and a hard disk emulator. This would have been very expensive.
A little searching of the Cromemco google group yielded an alternative solution which did not seem to have a lot of discussion. The S-100 community has created a lot of new board designs including a CF/IDE board designed by John Monahan. This board has CP/M support but “out of the box” there is no Cromix support. Fortunately, a talented chap, Damian Wildie up in Brisbane, has written a driver for Cromix. I contacted him to see if he would help me to get a CF/IDE card up and running, and he agreed without hesitation.
That left me needing the card itself. These cannot (as far as I know) be bought in an assembled or even kit state. The PCB was available locally which was a bit of a fluke; not many S-100 boards are available in Australia. I had already bought an extender card from the same seller. The rest of the parts came from stock, element14, ebay and wherever I could find them. Some of the parts are not easy to find here in Australia.
I built up the extender and the CF/IDE card and Damian came through with a disk image for the CF card and another for a boot floppy – the driver doesn’t allow for boot from the CF card but it can be the root filesystem. Damian even customised it for my system which was above and beyond.
After some problems with the first image and a couple of mysteries with the card (one turned out to be a badly soldered artificial resistor pack) the other I’m not sure about. I swapped out 54LS244s for 74F244s, and it got better – it may have been speed, but the sockets feel a little loose to me.
- Does not support booting
- The disks cannot be initialised from Cromix
- Diskinfo does not seem to always work.
The size of the disks seems to cause some issues for my 512kB system eg dcheck and icheck don’t work. This really means that the disk needs to be imaged regularly. (Resolved with increased memory – about 370k required to do the check!)
The major device number is 12. The first partition on card A has a minor number of 0. These need to be entered as the root device.
Damian has provided a customised gen directory at /usr/ide. Regeneration works fine.
Installation of apps is now a lot easier.
The /etc/ttys has been edited to set the terminals to Televideo 925 (T925 in termcaps) which works with the IBM terminal.
Users Admin, Graham, User1, and User2 have been added.
Messages have been customised. Damian (message is in ide_sysdef) and Vic have been acknowledged (/etc).
The help system works!
It is relatively easy to backup cards using dd even on Windows. Writing seems to be easier with balenaEtcher. I have bought some additional CF cards, but they seem to have some incompatibility. I will try a different brand.