Re: EPROM 341-0009 & 341-0010

[mjmahon@aol.com (Michael J. Mahon)]

Bryan Parkoff wrote:

>Paul,
>> I recently purchased the two FDD ROMs 341-0009 and 341-0010
>> for $5 each plus $3 shipping from these folks:
>>
>> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2781885240
>>
>> You only need the code ROM because the 16 sector state machine
>> ROM will work with the 13 sector code ROM.
>    Sorry, you are wrong.  Sixteen sector state machine ROM will not work
>with the 13 sector code ROM.  Slate Machine for 16 sectors and 13 sectors
>are very different because 16 sectors support two zero bits, but 13 sectors
>support only one zero bits.

No, Bryan, Paul is correct.

The 16-sector ROM will properly read both 13-sector and 16-sector
disks.  (If this were not true, then the BASICS pre-boot disk would
not be sufficient to run 13-sector disks on a 16-sector controller.)

Put another way, "one zero bit" is a subset of "up to two zero bits".

>    I do have binary data for Slate Machine that can be burned into EPROM
>chip.
>    You claim that you bought 341-0009 and 341-0010 from eBay.  You are
>probably mistaken that it is not truly 341-0009 and 341-0010.  It is true
>that photo does show the label that prints 341-0009 and 341-0010.  The
>seller does not have any 341-0009 and 341-0010.

So, wouldn't you expect that the logical explanation is that the seller
_used to have_ the ROMs, but is now sold out?

-michael

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