I just watched @This Does Not Compute 's video on the PowerBook 540c and was curious about the SCSI-IDE bridge on the upgraded HDD. That seems like a possibly good solution to retain a mechanical drive without spending a lot of money on a SCSI drive. Especially so for 2.5" drives. Is there an existing source for inexpensive bridges? Has anyone developed a reproduction PCB?
SCSI-IDE bridge
- Thread starter Elemenoh
- Start date
Here's a still from the video showing the component side of the board, for those curious. The machine's back together, but if there's serious interest from anyone who wants to reproduce it, I can pull the drive back out and scan both sides of the board.
That said -- given the components on it, I doubt the BOM for a replacement would be less than the cost of a BlueSCSI or SCSI2SD.
That said -- given the components on it, I doubt the BOM for a replacement would be less than the cost of a BlueSCSI or SCSI2SD.
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I don't think that will be reproduceable. The Lattice CPLD probably kills the deal. The K5C80 is a Z80 compatible processor made by Kawasaki. ??! I guess Kawasaki builds everything. I loved my '78 KZ1000. The only other notable chip is the 53CF96 which cost about $15 each these days. I don't why those are so expensive.
@Elemenoh SCSI-IDE bridges have gotten ridiculously expensive for some reason. I guess supply and demand. Back around 2007 you could get the Acard 7720U used for about $40 on Ebay. Now they're $250 if you can find them at all.
While that wouldn't solve your PowerBook craving, there aren't that many components. I'm looking at designing a PowerBook sized card and moving the components over. I would like to get my hands on a dead 2.5" SCSI drive so I'm sure to get teh dimensions just right...
@Elemenoh SCSI-IDE bridges have gotten ridiculously expensive for some reason. I guess supply and demand. Back around 2007 you could get the Acard 7720U used for about $40 on Ebay. Now they're $250 if you can find them at all.
While that wouldn't solve your PowerBook craving, there aren't that many components. I'm looking at designing a PowerBook sized card and moving the components over. I would like to get my hands on a dead 2.5" SCSI drive so I'm sure to get teh dimensions just right...
Does that mean you're looking into designing a modern SCSI/IDE bridge?
If you need a drive, I can send one to you.
I just made arrangements for a couple from a member over on 68kmla. But thank you for the kind offer.
No, nothing so ambitious. The Acard adapters have good, solid performance. Since the 7722 converts to a 7726 and is available for about $25 right now, I'm going to steal the bridge chip off of some 7722s and add a parallel => serial chip and socket to support MSATA. My goal is a 2.5" SCSI drive replacement with an MSATA drive as the storage. Since many MSATA controllers handle wear leveling automatically, this should relieve concerns that exist with using CF or SD cards in this application.
But at the rate I'm going right now, don't expect anything soon. Work keeps me mostly exhausted.
I would buy the ARC-760B chip separately, but the chip sellers want more for the bare chip, than the whole 7722 adapter sells for. Of course, a bare chip doesn't need desoldering and clean up, but still.
Thank you.
Work heated up again. Plus various aspects of life. I'm dead in the water on extraneous projects again.
Just mentioning in case anyone was anticipating me ever actually finishing the project. I hope to pick things up again, but not any time soon.
Hi @Elemenoh!
I am curious, why is the SCSI 2 IDE needed? What benefits would IDE have over the SD through SCSI 2 SD, such as BlueSCSI, available at reasonable prices for the priced Powerbooks? Unless that is because some vintage Macs do IDE for internal storage rather than SCSI?
@Elemenoh, I came across this web page about R-IDSC-E/R Experiments by bbraun. It looks like there are some ideas about bridging SCSI to IDE there. 
