Re: Apple IIgs AppleTalk and CD-ROM questions

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

Michael replied:

>Michael J. Mahon wrote:
>> The Apple II peripheral bus has a maximum transfer rate of 1MB/sec.
>> 
>> This can be achieved only with DMA.  Any other form of data transfer
>> will get a fraction of that speed.
>
>I know that, and it doesn't fit the explanation that my 12X (1.8 MB/sec) 
>CD-ROM drive crashes the machine occasionally, whereas the 5 MB/sec SCSI 
>hard disk does not.
>
>The RamFast would be doing DMA for both drives, as far as I can tell.

I didn't post this in reply to your question, but in reply to a
comment about how fast a peripheral would be useful on
an Apple II.

I expect that the more modern CD-ROM drive crashes the system
because it crashes the RAMFast firmware, which very likely does
not understand something that the CD-ROM is trying to tell it.

-michael

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