[Coco] Robocop on the cocoflash

[RETRO Innovations]

On 5/4/2017 7:43 PM, Barry Nelson wrote:
>> Rietveld Rietveld rietveldh at hotmail.com  <mailto:coco%40maltedmedia.com?Subject=Re%3A%20%5BCoco%5D%20Robocop%20on%20the%20cocoflash&In-Reply-To=%3CDM5PR14MB13068936DCE378A2221E540EB6EB0%40DM5PR14MB1306.namprd14.prod.outlook.com%3E>
>> Thu May 4 20:20:30 EDT 2017
>>
>> Btw if u know of a simpler solution I am definitely open to it. This was a bit more tedious than I thought
I think the progflash should be extended to support larger images directly:

  * scan the selected file to sense length.  Rewind pointer to disk file
  * if 32kB, then read and skip the first 16K in file
  * Write IMage:  for i = 1 to 4: read 4kB from file/select cocoflash
    slot/write 4kB
  * If 32kB image, rewind and repeat for first 16kB
  * if > 32kB, repeat for size of file / 16kB

Jim

>> ,
>>>    Original Message
>>> From: Barry Nelson
>>> Sent: Thursday, May 4, 2017 8:17 PM
>>> To: coco at maltedmedia.com <https://pairlist5.pair.net/mailman/listinfo/coco>
>>> Reply To: CoCoList for Color Computer Enthusiasts
>>> Subject: [Coco] Robocop on the cocoflash
>>>
>>>
>>> I am pretty certain that when I flashed this rom I did it from the lowest numbered segment to the highest, not highest to lowest.
>>>
>>> ??
> Because the CoCo can only access 64k of memory at one time, and because of the way the PRGFLASH program was designed to work on a CoCo 1, the maximum amount of rom that can be flashed at one time is 16k. Any rom larger than 16k must be broken into smaller pieces before being flashed.
>
> I am fairly certain that you should be flashing the lowest numbered segment first for any 64k or 128k rom such as Robocop. It is only the 32k rom image files where the two 16k segments are reversed. I believe this is discussed in the documentation. The reverse order for 32k roms really just has to do with the weird file format chosen for 32k ccc files. If you were to read the rom your self in an eprom burner, the segments would not be reversed, just for some reason someone arbitrarily decided that the ccc file format for 32k rom files would have the two 16k halves reversed, but only for 32k roms, non of the other sizes. I’ll be darned if I know why they did that.
>
>


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