27 May
2023
27 May
'23
11:37 p.m.
On Thu, May 25, 2023 at 12:52:39PM +0100, Tony Duell via cctalk wrote:
[...]
USB interfacing is hard, but SD cards are a lot
simpler. So use a card
reader thing to transfer the files to an SD card and design an
interface for that to ISA bus.
No need even to design anything or faff around copying files between formats
as flash-to-IDE widgets are available from the likes of AliExpress for
peanuts. Your choice of flash: CF, SD, mSATA, NVMe, there are widgets for
them all and probably some I've missed. On the IDE side you've got the chose
of male or female, 40- or 44-pin IDE. (Watch out for that "50-pin IDE" that
some of the less knowledgable sellers have, unless you actually want SCSI.)
Given free choice, I'm more inclined to go SD-to-IDE. CF cards may well
emulate IDE devices and can use a passive adaptor and so feel more
appropriate to the task, but unless you've got a nice cache of old CF cards
which aren't knackered, the cost of new ones are prohibitive as they're
intended for professional applications such as high-end digital cameras. SD
cards are dirt cheap unless you're buying them by the terabyte (and not
unreasonably expensive even then).
For the specific case of a desktop PC, there are CF-to-IDE widgets mounted
on a card slot bracket so you can swap cards without opening the machine
(but powering-down is probably wise). These are completely passive and don't
go into a slot, so can be installed in any machine it'll physically fit;
ISA, PCIe, Zorro, whatever. Depending on clearances, it might even be able
to share the same slot with a plug-in IDE controller.
SD extension cables are a thing for smaller machines without card slots. I
have one in my Amiga 1000 as the ribbon cable can be routed through quite
small gaps in the case.