[Coco] OS9 vs Flex

[John Kent]

I think the standard version of UniFlex for the SWTPc that they are 
trying to get going on the SWTPc emulator uses the DMAF-2 floppy Disk 
controller that uses a 6844 DMA controller and FD179X floppy disk 
controller. I was hoping to design a FPGA 6844 DMA controller and 
implement a FD179X interface to a CF card, to emulate the DMAF-2, but 
it's been a fairly low priority up until now.

The UniFlex Archive I think was at rtmx:

http://www.rtmx.com/UniFLEX/

I think the DMA was required for the 8" Double Density disks. I'm not 
sure that it would be a very easy job porting UniFlex to the CoCo3. It 
would need the extended memory of the CoCo3.

Has anyone interfaced high density 3.5" floppies to the CoCo ? Because 
you'd be up for the same problem with those. The data rate would be too 
fast for a 6809 software polling loop for the 1.44MB floppies. You'd 
need a floppy disk controller with sector buffering for the CoCo.

John.

On 1/01/2012 7:36 AM, Aaron Wolfe wrote:
> In Frank Hogg Laboratories ads in 68 mj, they refer to "Flex, UniFlex 
> and OS9" as three different operating systems, and offer different 
> versions of their software for each. I think when people say simply 
> "Flex" they mostly mean the original single tasking CP/M or MSDOS like 
> system, basically a bunch of routines at known/fixed memory locations 
> that a single program uses, the shell is unloaded when a program is 
> loaded, etc. Probably more useful than OS9 on a 64k system in some 
> applications simply due to lower memory footprint, but not nearly so 
> refined and powerful an OS. UniFlex is a multiuser/multitasking 
> environment that is somewhat Flex-like, but seems to need its own 
> versions of software. There are some good articles written by Frank 
> Hogg and others about exactly what UniFlex is, but I can't seem to 
> find them. There was a good deal of comparison from readers and 
> various authors of the two systems as well. Somewhere in those mags 
> are the gory details. Hard to judge popularity precisely, but it 
> seemed a lot more time was spent in the magazine talking about regular 
> Flex than UniFlex. 
> -- Coco mailing list Coco at maltedmedia.com 
> http://five.pairlist.net/mailman/listinfo/coco 

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