Hi Mike,
Here are the options to attach 3340 DASD emulation to an IBM System/3
1) direct connect to the internal channel of the S/3. Some disk OEM's did
this.
Requires a FPGA with at one side MST-1 interface logic and at the other side
IDE or SCSI interface.
The availabe IBM documentation is complete enough to finish this project.
You need good IBM HW & VHDL knowledge.
2) direct connect to the BUS/TAG interface connector.
This needs a 8+P bit stream. You have to do some reverse engineering to
figure out what the exact format is.
I have no idea if the HW must be implemented in a FPGA (for timing reasons)
or if an AVR processor will do the job.
Advantage is that you don't have to modify anything inside the S/3.
3) IBM has implemented an IOP (I/O Processor) between the S/3 CPU and the
3340 drives.
This IOP is a modified version of the ones used in the IBM 370/115 & 125. It
is a powerfull multi thread capable beast.
With small HW modification you can connect an IDE or SCSI drives to it.
The difficult part is modifying the firmware of the IOP. This requires a
special assembler (to be written) and very good assembler skill's.
All options requires quite alot of time to implement.
My 2 cents
Henk
I've recently been poking about with various bits of emulation with
hardware interfaces... Dave's MFM emulator; various SCSI-to-USB or
SCSI-to-SDcard devices; my Setasi RP12 Massbus disk emulator; the
Sigma Seven Lisa widget/ProFile emulator etc.
What about IBM channel-attached DASD?
There are various CPUs lying around in private collections and museums
- System/360s; System/370s; System/3 Model 15s; all used
channel-attached DASD: and working reliable disks are much rarer than
the damn CPUs!
Questions:
1. There are or were various 3rd party companies producing rather
obscure emulated DASD replacement subsystems - Virtualblue and Bustech
are two names that come to mind. Has anyone looked into the
possibility of using them to emulate older devices that would be
usable on the above vintage CPUs?
2. To those with hardware design experience: how big a task do you
reckon it would be to do this as a home-brew with modern hardware -
exactly as Dave did with his MFM emulator? Is it feasible? Do the
entire thing in software - Pi or Arduino or FPGA - with appropriate
driver electronics to drive a channel interface?
I've BCC'd some experts with experience - Rich Alderson; William
Donzelli; Henk Stegeman - in the hope that they'll be able to
contribute.
What do people reckon would be the best target for emulation? 3340
springs to mind initially... would that work on machines as old as
System/360s? It's about the *only* option for 5415 DASD...
(To digress briefly - a modern reimplementation of something like the
Setasi Massbus disk emulator would also be very useful; Rich - weren't
LCM working on something like that?)
Mike
http://www.corestore.org
'No greater love hath a man than he lay down his life for his brother.
Not for millions, not for glory, not for fame.
For one person, in the dark, where no one will ever know or see.'
To all readers/followers of this website - for those who love
classic/vintage computers - I want to wish all the best of the holiday
season no matter what your beliefs. In this day of political
correctness it is simply to acknowledge Mother Nature's transition
>from fall to winter and we should take time from our busy schedules to
reflect on this 'special' time of the year.
Happy computing!
Murray :)
My VAX4000-500 will no longer power up, with the PSU starting up and then
immediately shutting down. I suspect a possible short somewhere. I have
measured the resistance of the load presented to the PSU by connecting
probes to the backplane sockets used to power the machine. The odd one is
the 5V load. With all the boards in and drives inserted I measure a
resistance of about 4R. As I pulled out boards, drives and fans, it
gradually crept up to 6R. So with nothing connected to the backplane I get a
6R load across the 5V supply.
To my inexperienced mind, that seems a bit low. Should I expect such a
value, or should I be dismantling the box to investigate possible shorts or
failed components on the backplane?
Additionally, the 12V side seems to be charging a capacitor as the
resistance slowly climbs to about 130K. Is that reasonable? Again, nothing
but the backplane.
The 3.3 and -12V show very high resistance at all times.
Thanks
Rob
In the series "looking for drivers". I have taken to using DolchPac 65's as
my retro workhorses so I can multi-boot DOS, Win98 , WinNT, WinXP and Linux
while sticking weird old PCI and ISA interface cards in it. One of the OS
always ends up having some software for the card. It has a custom video card
that identifies itself as a "Trident Video Accelerator 3D Cyber9520". I
found the driver for Win98 which works very well, the machine came
pre-installed running NT, and Linux installs a driver that is a bit glitchy
but usable (I can't believe I could run modern Linux on this!). The video is
auto-recognized and the right driver installs under XP, but the default
version is ultra-buggy, video gets corrupted. Does anyone have an updated
driver for this chip? Internet didn't come up with anything apart from the
ones necessitating scary hardware scanners that crashed my old machine
anyhow.
Marc
Just wanted to say a very sincere Thank You to all the talented folks that
hang out here and call this place home, and also to wish you and yours a
Merry Christmas.
Best,
Jay West
jwest at classiccmp.org
>> -----Oorspronkelijk bericht-----
>> Van: cctalk [mailto:cctalk-bounces at classiccmp.org] Namens Terry
Stewart
>> Verzonden: dinsdag 22 december 2015 21:50
>> Aan: General Discussion: On-Topic and Off-Topic Posts
>> Onderwerp: Piggybacking 74LS logic chips to confirm a suspected fault
>>
>> Hi,
>>
>> I've written up my recent third Apple II repair, this time an Apple IIe.
>>
http://www.classic-computers.org.nz/blog/2015-12-22-appleiIIe-no-video.htm
>>
>> One interesting aspect of this repair is that piggy-backing a logic
chip helped
>> confirm a faulty one. I'd only ever used this technique with RAM.
>> I'm sure it only works if the chip has a particular type of fault,
but it worked this
>> time for me.
>>
>> Terry (Tez)
>
> I use a HP 10529A logic comparator on regular basis for fault finding
in ttl circuits.
> It compares a reference chip with the CUT (Chip under test;) it's a
very nice diagnostic tool.
> It's a bit like piggy backing just a little more sophisticated :0
>
> -Rik
In my experience, the type of socket you used is quite unreliable and
will tend to develop bad contacts. There is a reason they are cheap... I
would use a turned pin type socket instead, e g an Augat socket. They
will not let you down. More expensive, but considering the work involved
in replacing a socket and the risk of messing up the PCB, the cost is
negligible.
Jonas
BAMA is probably the best known site for old test equipment and amateur radio manuals, followed by Ebaman.
Dale H. Cook, GR / HP Collector, Roanoke/Lynchburg, VA
http://plymouthcolony.net/starcity/radios/index.html
> From: Guy Sotomayor
> It's typical of most of the vintage gear. Folks save the CPUs and ditch
> the peripherals.
It's not entirely sloth and stupidity, though. Disk drives in particular
(usually the biggest issue in this area) are complex precision machinery that
operate at very high speeds, etc, and working on them is a formidable job,
and requires specialized parts which are, in general, no longer available.
> I think the biggest problem is that there isn't a spec per-se on
> Massbus. A lot of reverse engineering will be required to make it work
> properly in all cases.
If it were done, though, that would be wonderful, especially for people with
PDP-11/70's; the UNIBUS on those machines is reputedly the slowest of any
PDP-11, so having mass storage on the MASSBUS is really necessary for good
performance. (Apologies for my -11 centrism in an IBM-focused thread... :-)
But finding the connectors (and probably the cables too) is going to be a
cast-iron nightmare. Maybe we could settle on an alternative (the way I think
we should switch to pairs of dual cards with Berg/DuPont headers, with
standard flat cables between them, to replace the now-unobtainable BC11-A's -
DEC showed this works, with the M9014/M9042..)
Noel
Is there anything like Appleworks 1.0 for the commodore 64? if so could
you be kind enough to give me the name of the program? I have searched
but have found nothing of any value. I just would like a checkbool
ledger and a savings spreadsheet.