The Cromemco GIT has a huge range of software, but being able to use it turned out to be somewhat more difficult than i had expected.
At this point i thought it may have been possible to run Z80 programs, but i didn’t know for sure, and i certainly didn’t know how to do it. I concentrated on 68000 software instead.
There is a huge catalogue that accompanies the hundreds of disk images in the archive. The range of software for 68000 is not huge, but there are some compilers, for example.
The catalogue also shows the disk format. It turned out that a lot of the disks with 68000 software were in a particular format referred to as Uniform, which i knew nothing about. As it turned out Cromix 20.09 knew nothing about it either, which left me with a problem.
By this stage searching the text catalogue was starting to get tedious, so i translated it to a spreadsheet. The repository is not static, so my spreadsheet is just a snap-shot:
Faced with this problem as i’m re-writing this a couple of years later, i would probably turn to Damian Wildie’s image manipulation program, cromix-fs, but that was beyond me back then.
I sought some help from the Cromemco google group and they were very helpful. They thought was that Uniform support was added at about version 31.50. This was much later than the simple 20.09. In fact, it had crossed over into Cromix Plus and into a new versioning scheme: Cromix Plus 150.
Things got very complex very fast at this point. For a start the boot and install disks were no longer 40 track images but RDOS 2.01 can only do 40 tracks so it would be necessary to construct a 40 track boot disk. (I could have made a new EPROM, but i was reluctant to mess with a working card.)
Also tricky is that Uniform support has to be included in the cromix.sys that is executed at boot. If the version in the repository has not included it, then it would need to be regenerated. And what if the install disks are actually in Uniform format?
And, wait, regeneration requires disk and memory space. Cromix Plus is bigger. The systems it supports are also bigger, and the configurations on the archives have more functions installed. That 512kB memory starts to look quite small, and the floppy disks claustrophobic.
The install itself is also larger. 20.09 essentials would fit on one 1.2MB disk. That’s not possible with Cromix Plus.
There was a lot of chicken and egg going on!
Just to add a little more complexity, somehow some of the archive disks had been archived with the wrong rotational speed, so before use it was necessary to “cleanse” them through the HxC software.
The speed should have been 360rpm, but was 300rpm. This is obvious in the track viewer in the hxc software. This can be corrected using the hxc software by converting IMD to raw and then importing the img as a raw file. They can then be exported as hfe and scp for Greaseweazle or gotek/flashfloppy.
The cromix format uses 1 boot track of 26x128B sectors with FM and the rest of the 2*77-1 are 16x512B sectors with MFM. The uniform format is 2*77*15*512B sectors with MFM. Getting the number of sectors wrong produces some odd results eg checksum errors on ftar/uniform disks!
After numerous attempts, i found a way through with the version 162 disks. These disks seemed to be close to original so that the existing cromix.sys was a bit smaller.
Three of the four installation disks were in uniform format (tarred). But the first one was not, and there was one more seemingly random disk that contained the regen directory for this version in the standard format. That was the “get out of gaol free card” that i needed.
Most of the Cromix Plus disks are 8”. That means that I had to construct a boot disk by copying the cromix.sys from the 8” boot disk to a 360k disk. Worse than that it turned out that bootloader from the 20.09 disks would not load the Cromix Plus cromix.sys.
I was able to create a boot disk by getting a copy of the Cromix Plus fdboot file and popping it into the /etc directory of the 20.09 root disk. Then I could use wboot to write the Cromix Plus bootloader to the 360k disk. That gave a Cromix Plus loader and a Cromix Plus cromix.sys. Having made one boot disk it was easy to make boot disks for other versions just by copying the cromix.sys file.
Once the system booted, i updated the sysdef to add the Uniform driver (uflop), regenerated cromix.sys, updated the boot disk, and created the device files for uniform disk drives.
I set up the following drives.
| Select | Current Setup | Play | Final? | Drives | Use |
| 0 | 5.25” 40 track DD | Gotek | Gotek | fda/sfda/ufda | Boot initially and then access to images. Good compromise because 360k works with RDOS 2.01 for boot and then the gotek switches format with the image |
| 1 | 8” | Gotek / 8” | 8” | fda/sfda/ufda | / |
| 2 | 8” | 8” | 8” | fda/ufda | /usr |
| 3 | 5.25” 80 track HD | 5.25” 80 track HD | 5.25” 80 track HD | fda/ufda | Temporary mounts eg /usr/help /gen |
This gave an absolute minimum system that would allow software to be installed on disks on the fourth floppy drive. I could install from disk images that were in Uniform format. Software disks would need to be mounted prior to use and help would not be available.
