[Coco] format memory (was) Gotek floppy emulator

Steven Hirsch snhirsch at gmail.com
Tue Feb 16 17:45:58 EST 2016


On Tue, 16 Feb 2016, William Astle wrote:

> For floppies, you have to issue a "write track" command to the 
> controller. (This includes anything that pretends to be a standard 
> floppy drive/controller combination.) That command *does* need the whole 
> track data in one lump, and the total size of that is larger than the 
> data size of 18 sectors. Depending on the specific implementation of the 
> floppy driver, this might require a system memory buffer the size of the 
> raw track data.

I've never seen a floppy disk controller that didn't require writing an 
entire track during format, but perhaps they exist.

The Coco CPU is not fast enough to piece together the proper byte sequence 
for a format-track command on the fly, so there's really no choice but to 
stage the entire image in memory.



-- 


More information about the Coco mailing list