<Golly! I wasn't aware that they actually put a SCSI controller on the
<board. That must have been several rev's later than mine. My two boards
Next rev. Also Ampro was one of the guns in setting the base SCSI spec
around 85ish.
<were the beta and first release. I put a couple of hundred of these into
<the field because I liked them and they allowed pretty compact packaging.
Not hard to understand.
<I was propping the door to a room in the basement with a couple of 10MB
<RODIME 3.5" drives which might work really well with this arrangement. I
<once ran one of these with a 1"-high 3.5"Sony drive which a PC believed wa
<a 1.2MB drive. Maybe I can fool the FDC drivers into doing a similar thing
<That would be handy. There's no "standard" 3.5" driver for CP/M.
I have 3.5" miniscribe 20mb MFM hooked to a xybec scsi bridge on a
SB180(also has 5380). Looks silly since the scsi bridge is larger than
the drive and the SB180s. It works because the drive is faster seek than
most older mfm drives like the st225 or 251. That and it throws less
heat.
<>Here we go again... I DIDN'T SAY IT WAS IDE. I said it was similar in
<>respect that it was a bus level interface for a controller and predates
<
<
<No, you surely didn't say that! It doesn't use the same cable definition o
<any thing like it. It just happens to use a 40-conductor cable. The reaso
Doesnt saying "its not IDE" cover that? I wes refering to the idea that
the bus can be a base micro IO bus (read, write, address, data, reset,
misc). That at the CONCEPT level is similar to IDE.
<I said I'd try modifying the firmware to talk to an IDE drive is that ther
<is reason to believe that the command structure is identical although the
<hardware would have to be modified to load the registers as it's done on th
<16-bit -WAH controller. The fact is that the 1000-05 and the 1002-05 bridg
<controller boards use the same chip (WD1010-05) as the HDD interface.
<That's where the command registers are located and they'll require
<programming in the same way. Since the IDE drive has, essentially, the sam
<register set on it to accomplish the controller functions, and the registe
<set mapped in the same way as the WD1003-WAH, it should be possible to mak
<it work similarly.
No yes at the concept level. At the real level the IDE has 16 bit data
path like the 1003, but the 1000-5 and 1002-5 tended to ahve differences
that are quite distinct. I turned them up while doing an article for TCJ.
That was about applying ISA-8 WD1002-WX cards as a cheap MFM host interface.
I found the -HDO board had a different address and register layout.
<>Finding them can be tough. the 6mhz are more common. 8530s or 8330s are
<>easier to find and offer better perfomance.
<>
<I'm really not that hot for it, but think it would be charming to put a se
<of '-H' parts in an early AMPRO Little Board and make it work at 8MHz. Th
<timing should work with 100ns DRAMs. Aside from the PROM, I doubt anythin
<other than the peripherals would be affected by the speed change. Of cours
There were articles for upgrading the amproLB to 8mhz. See TCJ
<www.psyber.com/~tcj>.
<the FDC would require a different tap from the clock divider, but everythin
<else should work as is, save, perhaps the PROM. The PROM might work if th
<clock switch were hacked as well. (I believe there was a little sorcery
<with switching the clock speed after copying the PROM into RAM, by switchin
<the preset on a counter. What I liked about this was the really sensible
Why not goo whole hog if your going to switch clock speeds and do clock
stuttering. That way only certain parts or the processor cycle are
stretched and the rest can run full bore.
<packaging you could use with these small boards. I have a video
<display/keyboard on a similar form factor which I'd really like to package
<with these other two boards and the drives. That would be truly minimalis
<for the time.
I packed mine in a box I found at DEC (oddball) that was very compact. It
also allows for external DC power (battery and solar) as mine has been
modded to take mostly cmos parts (CPU, CTC, SIOs, EPROM, 53C80, and some
of the losse ttl to 74hct). Power is way down.
Allison
Received on Sat Apr 17 1999 - 09:43:54 BST