I just found this very tasty tidbit:
http://www.freeinfosociety.com/electronics/schemview.php?id=1475
The ole' wooden cogs betwixt the ears began to smokin' . . .
. . . so I whipped out my trusty, special ordered waaaaayyyyy back in the day, copy of DCaDftMF AKA: Designing Cards and Drivers for the Macintosh Family. And found the SCSI-NuBus Test Card design example I remembered, fully documented therein!
I quote: DCaDftMF p. 231 "The SCSI-NuBus Test Card is an example of how a simple 8-bit I/O chip may be supported over NuBus."
What better example of an (intelligent/programmable) 8-bit I/O chip is there than the Z80 family, a PIC emulating a Z80 maybe?
Question: can the modern Z80 family support throughput from a modern IDE HDD or SATA HDD/IDE Bridge combo that would compare favorably with yesteryear's Fast/Wide SCSI HDDs or RAIDs on a JackHammer NuBus Card?
From what I gather, it's not all that hard to swamp NuBus I/O, especially so with a pre-NuBus '90 design, I would think. Unfortunately, the design examples in this 1992 tome were prepared before the NuBus '90 specification. Were the Fast/Wide SCSI 2 NuBus cards vanilla NuBus or NuBus '90?
Food for thought . . . [}
] ]'>
This kinda stuff is waaayyyyy over my head! :
http://www.freeinfosociety.com/electronics/schemview.php?id=1475
The ole' wooden cogs betwixt the ears began to smokin' . . .
. . . so I whipped out my trusty, special ordered waaaaayyyyy back in the day, copy of DCaDftMF AKA: Designing Cards and Drivers for the Macintosh Family. And found the SCSI-NuBus Test Card design example I remembered, fully documented therein!
I quote: DCaDftMF p. 231 "The SCSI-NuBus Test Card is an example of how a simple 8-bit I/O chip may be supported over NuBus."
What better example of an (intelligent/programmable) 8-bit I/O chip is there than the Z80 family, a PIC emulating a Z80 maybe?
Question: can the modern Z80 family support throughput from a modern IDE HDD or SATA HDD/IDE Bridge combo that would compare favorably with yesteryear's Fast/Wide SCSI HDDs or RAIDs on a JackHammer NuBus Card?
From what I gather, it's not all that hard to swamp NuBus I/O, especially so with a pre-NuBus '90 design, I would think. Unfortunately, the design examples in this 1992 tome were prepared before the NuBus '90 specification. Were the Fast/Wide SCSI 2 NuBus cards vanilla NuBus or NuBus '90?
Food for thought . . . [}
] ]'>This kinda stuff is waaayyyyy over my head! :